From c89126eabb1ec17ab3af43ec7975bc49fdc729aa Mon Sep 17 00:00:00 2001 From: Dan Magenheimer Date: Wed, 15 Feb 2012 07:54:18 -0800 Subject: [PATCH] staging: ramster: ramster-specific changes to zcache/tmem RAMster implements peer-to-peer transcendent memory, allowing a "cluster" of kernels to dynamically pool their RAM. This patch incorporates changes transforming zcache to work with a remote store. In tmem.[ch], new "repatriate" (provoke async get) and "localify" (handle incoming data resulting from an async get) routines combine with a handful of changes to existing pamops interfaces allow the generic tmem code to support asynchronous operations. Also, a new tmem_xhandle struct groups together key information that must be passed to remote tmem stores. Zcache-main.c is augmented with a large amount of ramster-specific code to handle remote operations and "foreign" pages on both ends of the "remotify" protocol. New "foreign" pools are auto-created on demand. A "selfshrinker" thread periodically repatriates remote persistent pages when local memory conditions allow. For certain operations, a queue is necessary to guarantee strict ordering as out-of-order puts/flushes can cause strange race conditions. Pampd pointers now either point to local memory OR describe a remote page; to allow the same 64-bits to describe either, the LSB is used to differentiate. Some acrobatics must be performed to ensure local memory is available to handle a remote persistent get, or deal with the data directly anyway if the malloc failed. Lots of ramster-specific statistics are available via sysfs. Note: Some debug ifdefs left in for now. Signed-off-by: Dan Magenheimer Signed-off-by: Greg Kroah-Hartman --- drivers/staging/ramster/Kconfig | 18 +- drivers/staging/ramster/Makefile | 4 +- drivers/staging/ramster/tmem.c | 115 +- drivers/staging/ramster/tmem.h | 46 +- drivers/staging/ramster/zcache-main.c | 1850 +++++++++++++++++++++---- 5 files changed, 1741 insertions(+), 292 deletions(-) diff --git a/drivers/staging/ramster/Kconfig b/drivers/staging/ramster/Kconfig index 7fabcb2bc80d..acfb974f9ef0 100644 --- a/drivers/staging/ramster/Kconfig +++ b/drivers/staging/ramster/Kconfig @@ -1,13 +1,13 @@ -config ZCACHE - tristate "Dynamic compression of swap pages and clean pagecache pages" - depends on CLEANCACHE || FRONTSWAP - select XVMALLOC +config RAMSTER + bool "Cross-machine RAM capacity sharing, aka peer-to-peer tmem" + depends on (CLEANCACHE || FRONTSWAP) && CONFIGFS_FS && !ZCACHE && !XVMALLOC && !HIGHMEM select LZO_COMPRESS select LZO_DECOMPRESS default n help - Zcache doubles RAM efficiency while providing a significant - performance boosts on many workloads. Zcache uses lzo1x - compression and an in-kernel implementation of transcendent - memory to store clean page cache pages and swap in RAM, - providing a noticeable reduction in disk I/O. + RAMster allows RAM on other machines in a cluster to be utilized + dynamically and symmetrically instead of swapping to a local swap + disk, thus improving performance on memory-constrained workloads + while minimizing total RAM across the cluster. RAMster, like + zcache, compresses swap pages into local RAM, but then remotifies + the compressed pages to another node in the RAMster cluster. diff --git a/drivers/staging/ramster/Makefile b/drivers/staging/ramster/Makefile index 60daa272c204..bcc13c87f996 100644 --- a/drivers/staging/ramster/Makefile +++ b/drivers/staging/ramster/Makefile @@ -1,3 +1 @@ -zcache-y := zcache-main.o tmem.o - -obj-$(CONFIG_ZCACHE) += zcache.o +obj-$(CONFIG_RAMSTER) += zcache-main.o tmem.o r2net.o xvmalloc.o cluster/ diff --git a/drivers/staging/ramster/tmem.c b/drivers/staging/ramster/tmem.c index 1ca66ea9b281..8f2f6892d8d3 100644 --- a/drivers/staging/ramster/tmem.c +++ b/drivers/staging/ramster/tmem.c @@ -27,6 +27,7 @@ #include #include #include +#include #include "tmem.h" @@ -316,7 +317,7 @@ static void *tmem_pampd_lookup_in_obj(struct tmem_obj *obj, uint32_t index) } static void *tmem_pampd_replace_in_obj(struct tmem_obj *obj, uint32_t index, - void *new_pampd) + void *new_pampd, bool no_free) { struct tmem_objnode **slot; void *ret = NULL; @@ -325,7 +326,9 @@ static void *tmem_pampd_replace_in_obj(struct tmem_obj *obj, uint32_t index, if ((slot != NULL) && (*slot != NULL)) { void *old_pampd = *(void **)slot; *(void **)slot = new_pampd; - (*tmem_pamops.free)(old_pampd, obj->pool, NULL, 0); + if (!no_free) + (*tmem_pamops.free)(old_pampd, obj->pool, + NULL, 0, false); ret = new_pampd; } return ret; @@ -481,7 +484,7 @@ static void tmem_objnode_node_destroy(struct tmem_obj *obj, if (ht == 1) { obj->pampd_count--; (*tmem_pamops.free)(objnode->slots[i], - obj->pool, NULL, 0); + obj->pool, NULL, 0, true); objnode->slots[i] = NULL; continue; } @@ -498,7 +501,8 @@ static void tmem_pampd_destroy_all_in_obj(struct tmem_obj *obj) return; if (obj->objnode_tree_height == 0) { obj->pampd_count--; - (*tmem_pamops.free)(obj->objnode_tree_root, obj->pool, NULL, 0); + (*tmem_pamops.free)(obj->objnode_tree_root, + obj->pool, NULL, 0, true); } else { tmem_objnode_node_destroy(obj, obj->objnode_tree_root, obj->objnode_tree_height); @@ -529,7 +533,7 @@ static void tmem_pampd_destroy_all_in_obj(struct tmem_obj *obj) * always flushes for simplicity. */ int tmem_put(struct tmem_pool *pool, struct tmem_oid *oidp, uint32_t index, - char *data, size_t size, bool raw, bool ephemeral) + char *data, size_t size, bool raw, int ephemeral) { struct tmem_obj *obj = NULL, *objfound = NULL, *objnew = NULL; void *pampd = NULL, *pampd_del = NULL; @@ -545,7 +549,7 @@ int tmem_put(struct tmem_pool *pool, struct tmem_oid *oidp, uint32_t index, /* if found, is a dup put, flush the old one */ pampd_del = tmem_pampd_delete_from_obj(obj, index); BUG_ON(pampd_del != pampd); - (*tmem_pamops.free)(pampd, pool, oidp, index); + (*tmem_pamops.free)(pampd, pool, oidp, index, true); if (obj->pampd_count == 0) { objnew = obj; objfound = NULL; @@ -576,7 +580,7 @@ delete_and_free: (void)tmem_pampd_delete_from_obj(obj, index); free: if (pampd) - (*tmem_pamops.free)(pampd, pool, NULL, 0); + (*tmem_pamops.free)(pampd, pool, NULL, 0, true); if (objnew) { tmem_obj_free(objnew, hb); (*tmem_hostops.obj_free)(objnew, pool); @@ -586,6 +590,65 @@ out: return ret; } +void *tmem_localify_get_pampd(struct tmem_pool *pool, struct tmem_oid *oidp, + uint32_t index, struct tmem_obj **ret_obj, + void **saved_hb) +{ + struct tmem_hashbucket *hb; + struct tmem_obj *obj = NULL; + void *pampd = NULL; + + hb = &pool->hashbucket[tmem_oid_hash(oidp)]; + spin_lock(&hb->lock); + obj = tmem_obj_find(hb, oidp); + if (likely(obj != NULL)) + pampd = tmem_pampd_lookup_in_obj(obj, index); + *ret_obj = obj; + *saved_hb = (void *)hb; + /* note, hashbucket remains locked */ + return pampd; +} + +void tmem_localify_finish(struct tmem_obj *obj, uint32_t index, + void *pampd, void *saved_hb, bool delete) +{ + struct tmem_hashbucket *hb = (struct tmem_hashbucket *)saved_hb; + + BUG_ON(!spin_is_locked(&hb->lock)); + if (pampd != NULL) { + BUG_ON(obj == NULL); + (void)tmem_pampd_replace_in_obj(obj, index, pampd, 1); + } else if (delete) { + BUG_ON(obj == NULL); + (void)tmem_pampd_delete_from_obj(obj, index); + } + spin_unlock(&hb->lock); +} + +static int tmem_repatriate(void **ppampd, struct tmem_hashbucket *hb, + struct tmem_pool *pool, struct tmem_oid *oidp, + uint32_t index, bool free, char *data) +{ + void *old_pampd = *ppampd, *new_pampd = NULL; + bool intransit = false; + int ret = 0; + + + if (!is_ephemeral(pool)) + new_pampd = (*tmem_pamops.repatriate_preload)( + old_pampd, pool, oidp, index, &intransit); + if (intransit) + ret = -EAGAIN; + else if (new_pampd != NULL) + *ppampd = new_pampd; + /* must release the hb->lock else repatriate can't sleep */ + spin_unlock(&hb->lock); + if (!intransit) + ret = (*tmem_pamops.repatriate)(old_pampd, new_pampd, pool, + oidp, index, free, data); + return ret; +} + /* * "Get" a page, e.g. if one can be found, copy the tmem page with the * matching handle from PAM space to the kernel. By tmem definition, @@ -607,14 +670,36 @@ int tmem_get(struct tmem_pool *pool, struct tmem_oid *oidp, uint32_t index, int ret = -1; struct tmem_hashbucket *hb; bool free = (get_and_free == 1) || ((get_and_free == 0) && ephemeral); - bool lock_held = false; + bool lock_held = 0; + void **ppampd; +again: hb = &pool->hashbucket[tmem_oid_hash(oidp)]; spin_lock(&hb->lock); - lock_held = true; + lock_held = 1; obj = tmem_obj_find(hb, oidp); if (obj == NULL) goto out; + ppampd = __tmem_pampd_lookup_in_obj(obj, index); + if (ppampd == NULL) + goto out; + if (tmem_pamops.is_remote(*ppampd)) { + ret = tmem_repatriate(ppampd, hb, pool, oidp, + index, free, data); + lock_held = 0; /* note hb->lock has been unlocked */ + if (ret == -EAGAIN) { + /* rare I think, but should cond_resched()??? */ + usleep_range(10, 1000); + goto again; + } else if (ret != 0) { + if (ret != -ENOENT) + pr_err("UNTESTED case in tmem_get, ret=%d\n", + ret); + ret = -1; + goto out; + } + goto out; + } if (free) pampd = tmem_pampd_delete_from_obj(obj, index); else @@ -628,10 +713,6 @@ int tmem_get(struct tmem_pool *pool, struct tmem_oid *oidp, uint32_t index, obj = NULL; } } - if (tmem_pamops.is_remote(pampd)) { - lock_held = false; - spin_unlock(&hb->lock); - } if (free) ret = (*tmem_pamops.get_data_and_free)( data, size, raw, pampd, pool, oidp, index); @@ -668,7 +749,7 @@ int tmem_flush_page(struct tmem_pool *pool, pampd = tmem_pampd_delete_from_obj(obj, index); if (pampd == NULL) goto out; - (*tmem_pamops.free)(pampd, pool, oidp, index); + (*tmem_pamops.free)(pampd, pool, oidp, index, true); if (obj->pampd_count == 0) { tmem_obj_free(obj, hb); (*tmem_hostops.obj_free)(obj, pool); @@ -682,8 +763,8 @@ out: /* * If a page in tmem matches the handle, replace the page so that any - * subsequent "get" gets the new page. Returns 0 if - * there was a page to replace, else returns -1. + * subsequent "get" gets the new page. Returns the new page if + * there was a page to replace, else returns NULL. */ int tmem_replace(struct tmem_pool *pool, struct tmem_oid *oidp, uint32_t index, void *new_pampd) @@ -697,7 +778,7 @@ int tmem_replace(struct tmem_pool *pool, struct tmem_oid *oidp, obj = tmem_obj_find(hb, oidp); if (obj == NULL) goto out; - new_pampd = tmem_pampd_replace_in_obj(obj, index, new_pampd); + new_pampd = tmem_pampd_replace_in_obj(obj, index, new_pampd, 0); ret = (*tmem_pamops.replace_in_obj)(new_pampd, obj); out: spin_unlock(&hb->lock); diff --git a/drivers/staging/ramster/tmem.h b/drivers/staging/ramster/tmem.h index ed147c4b110d..47f1918c8314 100644 --- a/drivers/staging/ramster/tmem.h +++ b/drivers/staging/ramster/tmem.h @@ -9,7 +9,6 @@ #ifndef _TMEM_H_ #define _TMEM_H_ -#include #include #include #include @@ -89,6 +88,31 @@ struct tmem_oid { uint64_t oid[3]; }; +struct tmem_xhandle { + uint8_t client_id; + uint8_t xh_data_cksum; + uint16_t xh_data_size; + uint16_t pool_id; + struct tmem_oid oid; + uint32_t index; + void *extra; +}; + +static inline struct tmem_xhandle tmem_xhandle_fill(uint16_t client_id, + struct tmem_pool *pool, + struct tmem_oid *oidp, + uint32_t index) +{ + struct tmem_xhandle xh; + xh.client_id = client_id; + xh.xh_data_cksum = (uint8_t)-1; + xh.xh_data_size = (uint16_t)-1; + xh.pool_id = pool->pool_id; + xh.oid = *oidp; + xh.index = index; + return xh; +} + static inline void tmem_oid_set_invalid(struct tmem_oid *oidp) { oidp->oid[0] = oidp->oid[1] = oidp->oid[2] = -1UL; @@ -147,7 +171,11 @@ struct tmem_obj { unsigned int objnode_tree_height; unsigned long objnode_count; long pampd_count; - void *extra; /* for private use by pampd implementation */ + /* for current design of ramster, all pages belonging to + * an object reside on the same remotenode and extra is + * used to record the number of the remotenode so a + * flush-object operation can specify it */ + void *extra; /* for use by pampd implementation */ DECL_SENTINEL }; @@ -174,9 +202,14 @@ struct tmem_pamops { int (*get_data_and_free)(char *, size_t *, bool, void *, struct tmem_pool *, struct tmem_oid *, uint32_t); - void (*free)(void *, struct tmem_pool *, struct tmem_oid *, uint32_t); + void (*free)(void *, struct tmem_pool *, + struct tmem_oid *, uint32_t, bool); void (*free_obj)(struct tmem_pool *, struct tmem_obj *); bool (*is_remote)(void *); + void *(*repatriate_preload)(void *, struct tmem_pool *, + struct tmem_oid *, uint32_t, bool *); + int (*repatriate)(void *, void *, struct tmem_pool *, + struct tmem_oid *, uint32_t, bool, void *); void (*new_obj)(struct tmem_obj *); int (*replace_in_obj)(void *, struct tmem_obj *); }; @@ -193,11 +226,16 @@ extern void tmem_register_hostops(struct tmem_hostops *m); /* core tmem accessor functions */ extern int tmem_put(struct tmem_pool *, struct tmem_oid *, uint32_t index, - char *, size_t, bool, bool); + char *, size_t, bool, int); extern int tmem_get(struct tmem_pool *, struct tmem_oid *, uint32_t index, char *, size_t *, bool, int); extern int tmem_replace(struct tmem_pool *, struct tmem_oid *, uint32_t index, void *); +extern void *tmem_localify_get_pampd(struct tmem_pool *, struct tmem_oid *, + uint32_t index, struct tmem_obj **, + void **); +extern void tmem_localify_finish(struct tmem_obj *, uint32_t index, + void *, void *, bool); extern int tmem_flush_page(struct tmem_pool *, struct tmem_oid *, uint32_t index); extern int tmem_flush_object(struct tmem_pool *, struct tmem_oid *); diff --git a/drivers/staging/ramster/zcache-main.c b/drivers/staging/ramster/zcache-main.c index 49c8791462f4..36d53ed9d71a 100644 --- a/drivers/staging/ramster/zcache-main.c +++ b/drivers/staging/ramster/zcache-main.c @@ -1,7 +1,7 @@ /* * zcache.c * - * Copyright (c) 2010,2011, Dan Magenheimer, Oracle Corp. + * Copyright (c) 2010-2012, Dan Magenheimer, Oracle Corp. * Copyright (c) 2010,2011, Nitin Gupta * * Zcache provides an in-kernel "host implementation" for transcendent memory @@ -17,6 +17,9 @@ * * [1] For a definition of page-accessible memory (aka PAM), see: * http://marc.info/?l=linux-mm&m=127811271605009 + * RAMSTER TODO: + * - handle remotifying of buddied pages (see zbud_remotify_zbpg) + * - kernel boot params: nocleancache/nofrontswap don't always work?!? */ #include @@ -30,11 +33,16 @@ #include #include #include "tmem.h" +#include "zcache.h" +#include "ramster.h" +#include "cluster/tcp.h" -#include "../zram/xvmalloc.h" /* if built in drivers/staging */ +#include "xvmalloc.h" /* temporary until change to zsmalloc */ + +#define RAMSTER_TESTING #if (!defined(CONFIG_CLEANCACHE) && !defined(CONFIG_FRONTSWAP)) -#error "zcache is useless without CONFIG_CLEANCACHE or CONFIG_FRONTSWAP" +#error "ramster is useless without CONFIG_CLEANCACHE or CONFIG_FRONTSWAP" #endif #ifdef CONFIG_CLEANCACHE #include @@ -43,6 +51,61 @@ #include #endif +enum ramster_remotify_op { + RAMSTER_REMOTIFY_EPH_PUT, + RAMSTER_REMOTIFY_PERS_PUT, + RAMSTER_REMOTIFY_FLUSH_PAGE, + RAMSTER_REMOTIFY_FLUSH_OBJ, + RAMSTER_INTRANSIT_PERS +}; + +struct ramster_remotify_hdr { + enum ramster_remotify_op op; + struct list_head list; +}; + +#define ZBH_SENTINEL 0x43214321 +#define ZBPG_SENTINEL 0xdeadbeef + +#define ZBUD_MAX_BUDS 2 + +struct zbud_hdr { + struct ramster_remotify_hdr rem_op; + uint16_t client_id; + uint16_t pool_id; + struct tmem_oid oid; + uint32_t index; + uint16_t size; /* compressed size in bytes, zero means unused */ + DECL_SENTINEL +}; + +#define ZVH_SENTINEL 0x43214321 +static const int zv_max_page_size = (PAGE_SIZE / 8) * 7; + +struct zv_hdr { + struct ramster_remotify_hdr rem_op; + uint16_t client_id; + uint16_t pool_id; + struct tmem_oid oid; + uint32_t index; + DECL_SENTINEL +}; + +struct flushlist_node { + struct ramster_remotify_hdr rem_op; + struct tmem_xhandle xh; +}; + +union { + struct ramster_remotify_hdr rem_op; + struct zv_hdr zv; + struct zbud_hdr zbud; + struct flushlist_node flist; +} remotify_list_node; + +static LIST_HEAD(zcache_rem_op_list); +static DEFINE_SPINLOCK(zcache_rem_op_list_lock); + #if 0 /* this is more aggressive but may cause other problems? */ #define ZCACHE_GFP_MASK (GFP_ATOMIC | __GFP_NORETRY | __GFP_NOWARN) @@ -98,20 +161,6 @@ static inline bool is_local_client(struct zcache_client *cli) * read or written unless the zbpg's lock is held. */ -#define ZBH_SENTINEL 0x43214321 -#define ZBPG_SENTINEL 0xdeadbeef - -#define ZBUD_MAX_BUDS 2 - -struct zbud_hdr { - uint16_t client_id; - uint16_t pool_id; - struct tmem_oid oid; - uint32_t index; - uint16_t size; /* compressed size in bytes, zero means unused */ - DECL_SENTINEL -}; - struct zbud_page { struct list_head bud_list; spinlock_t lock; @@ -141,20 +190,43 @@ static unsigned long zcache_zbud_buddied_count; /* protects the buddied list and all unbuddied lists */ static DEFINE_SPINLOCK(zbud_budlists_spinlock); -static LIST_HEAD(zbpg_unused_list); -static unsigned long zcache_zbpg_unused_list_count; - -/* protects the unused page list */ -static DEFINE_SPINLOCK(zbpg_unused_list_spinlock); - static atomic_t zcache_zbud_curr_raw_pages; static atomic_t zcache_zbud_curr_zpages; static unsigned long zcache_zbud_curr_zbytes; static unsigned long zcache_zbud_cumul_zpages; static unsigned long zcache_zbud_cumul_zbytes; static unsigned long zcache_compress_poor; +static unsigned long zcache_policy_percent_exceeded; static unsigned long zcache_mean_compress_poor; +/* + * RAMster counters + * - Remote pages are pages with a local pampd but the data is remote + * - Foreign pages are pages stored locally but belonging to another node + */ +static atomic_t ramster_remote_pers_pages = ATOMIC_INIT(0); +static unsigned long ramster_pers_remotify_enable; +static unsigned long ramster_eph_remotify_enable; +static unsigned long ramster_eph_pages_remoted; +static unsigned long ramster_eph_pages_remote_failed; +static unsigned long ramster_pers_pages_remoted; +static unsigned long ramster_pers_pages_remote_failed; +static unsigned long ramster_pers_pages_remote_nomem; +static unsigned long ramster_remote_objects_flushed; +static unsigned long ramster_remote_object_flushes_failed; +static unsigned long ramster_remote_pages_flushed; +static unsigned long ramster_remote_page_flushes_failed; +static unsigned long ramster_remote_eph_pages_succ_get; +static unsigned long ramster_remote_pers_pages_succ_get; +static unsigned long ramster_remote_eph_pages_unsucc_get; +static unsigned long ramster_remote_pers_pages_unsucc_get; +static atomic_t ramster_curr_flnode_count = ATOMIC_INIT(0); +static unsigned long ramster_curr_flnode_count_max; +static atomic_t ramster_foreign_eph_pampd_count = ATOMIC_INIT(0); +static unsigned long ramster_foreign_eph_pampd_count_max; +static atomic_t ramster_foreign_pers_pampd_count = ATOMIC_INIT(0); +static unsigned long ramster_foreign_pers_pampd_count_max; + /* forward references */ static void *zcache_get_free_page(void); static void zcache_free_page(void *p); @@ -210,6 +282,29 @@ static char *zbud_data(struct zbud_hdr *zh, unsigned size) return p; } +static void zbud_copy_from_pampd(char *data, size_t *size, struct zbud_hdr *zh) +{ + struct zbud_page *zbpg; + char *p; + unsigned budnum; + + ASSERT_SENTINEL(zh, ZBH); + budnum = zbud_budnum(zh); + zbpg = container_of(zh, struct zbud_page, buddy[budnum]); + spin_lock(&zbpg->lock); + BUG_ON(zh->size > *size); + p = (char *)zbpg; + if (budnum == 0) + p += ((sizeof(struct zbud_page) + CHUNK_SIZE - 1) & + CHUNK_MASK); + else if (budnum == 1) + p += PAGE_SIZE - ((zh->size + CHUNK_SIZE - 1) & CHUNK_MASK); + /* client should be filled in by caller */ + memcpy(data, p, zh->size); + *size = zh->size; + spin_unlock(&zbpg->lock); +} + /* * zbud raw page management */ @@ -218,38 +313,17 @@ static struct zbud_page *zbud_alloc_raw_page(void) { struct zbud_page *zbpg = NULL; struct zbud_hdr *zh0, *zh1; - bool recycled = 0; - - /* if any pages on the zbpg list, use one */ - spin_lock(&zbpg_unused_list_spinlock); - if (!list_empty(&zbpg_unused_list)) { - zbpg = list_first_entry(&zbpg_unused_list, - struct zbud_page, bud_list); - list_del_init(&zbpg->bud_list); - zcache_zbpg_unused_list_count--; - recycled = 1; - } - spin_unlock(&zbpg_unused_list_spinlock); - if (zbpg == NULL) - /* none on zbpg list, try to get a kernel page */ zbpg = zcache_get_free_page(); if (likely(zbpg != NULL)) { INIT_LIST_HEAD(&zbpg->bud_list); zh0 = &zbpg->buddy[0]; zh1 = &zbpg->buddy[1]; spin_lock_init(&zbpg->lock); - if (recycled) { - ASSERT_INVERTED_SENTINEL(zbpg, ZBPG); - SET_SENTINEL(zbpg, ZBPG); - BUG_ON(zh0->size != 0 || tmem_oid_valid(&zh0->oid)); - BUG_ON(zh1->size != 0 || tmem_oid_valid(&zh1->oid)); - } else { - atomic_inc(&zcache_zbud_curr_raw_pages); - INIT_LIST_HEAD(&zbpg->bud_list); - SET_SENTINEL(zbpg, ZBPG); - zh0->size = 0; zh1->size = 0; - tmem_oid_set_invalid(&zh0->oid); - tmem_oid_set_invalid(&zh1->oid); - } + atomic_inc(&zcache_zbud_curr_raw_pages); + INIT_LIST_HEAD(&zbpg->bud_list); + SET_SENTINEL(zbpg, ZBPG); + zh0->size = 0; zh1->size = 0; + tmem_oid_set_invalid(&zh0->oid); + tmem_oid_set_invalid(&zh1->oid); } return zbpg; } @@ -265,10 +339,8 @@ static void zbud_free_raw_page(struct zbud_page *zbpg) BUG_ON(zh1->size != 0 || tmem_oid_valid(&zh1->oid)); INVERT_SENTINEL(zbpg, ZBPG); spin_unlock(&zbpg->lock); - spin_lock(&zbpg_unused_list_spinlock); - list_add(&zbpg->bud_list, &zbpg_unused_list); - zcache_zbpg_unused_list_count++; - spin_unlock(&zbpg_unused_list_spinlock); + atomic_dec(&zcache_zbud_curr_raw_pages); + zcache_free_page(zbpg); } /* @@ -299,6 +371,10 @@ static void zbud_free_and_delist(struct zbud_hdr *zh) struct zbud_page *zbpg = container_of(zh, struct zbud_page, buddy[budnum]); + /* FIXME, should be BUG_ON, pool destruction path doesn't disable + * interrupts tmem_destroy_pool()->tmem_pampd_destroy_all_in_obj()-> + * tmem_objnode_node_destroy()-> zcache_pampd_free() */ + WARN_ON(!irqs_disabled()); spin_lock(&zbpg->lock); if (list_empty(&zbpg->bud_list)) { /* ignore zombie page... see zbud_evict_pages() */ @@ -358,8 +434,8 @@ static struct zbud_hdr *zbud_create(uint16_t client_id, uint16_t pool_id, if (unlikely(zbpg == NULL)) goto out; /* ok, have a page, now compress the data before taking locks */ - spin_lock(&zbpg->lock); spin_lock(&zbud_budlists_spinlock); + spin_lock(&zbpg->lock); list_add_tail(&zbpg->bud_list, &zbud_unbuddied[nchunks].list); zbud_unbuddied[nchunks].count++; zh = &zbpg->buddy[0]; @@ -389,12 +465,10 @@ init_zh: zh->oid = *oid; zh->pool_id = pool_id; zh->client_id = client_id; - /* can wait to copy the data until the list locks are dropped */ - spin_unlock(&zbud_budlists_spinlock); - to = zbud_data(zh, size); memcpy(to, cdata, size); spin_unlock(&zbpg->lock); + spin_unlock(&zbud_budlists_spinlock); zbud_cumul_chunk_counts[nchunks]++; atomic_inc(&zcache_zbud_curr_zpages); zcache_zbud_cumul_zpages++; @@ -458,9 +532,9 @@ static void zbud_evict_zbpg(struct zbud_page *zbpg) uint32_t index[ZBUD_MAX_BUDS]; struct tmem_oid oid[ZBUD_MAX_BUDS]; struct tmem_pool *pool; + unsigned long flags; ASSERT_SPINLOCK(&zbpg->lock); - BUG_ON(!list_empty(&zbpg->bud_list)); for (i = 0, j = 0; i < ZBUD_MAX_BUDS; i++) { zh = &zbpg->buddy[i]; if (zh->size) { @@ -469,20 +543,18 @@ static void zbud_evict_zbpg(struct zbud_page *zbpg) oid[j] = zh->oid; index[j] = zh->index; j++; - zbud_free(zh); } } spin_unlock(&zbpg->lock); for (i = 0; i < j; i++) { pool = zcache_get_pool_by_id(client_id[i], pool_id[i]); - if (pool != NULL) { - tmem_flush_page(pool, &oid[i], index[i]); - zcache_put_pool(pool); - } + BUG_ON(pool == NULL); + local_irq_save(flags); + /* these flushes should dispose of any local storage */ + tmem_flush_page(pool, &oid[i], index[i]); + local_irq_restore(flags); + zcache_put_pool(pool); } - ASSERT_SENTINEL(zbpg, ZBPG); - spin_lock(&zbpg->lock); - zbud_free_raw_page(zbpg); } /* @@ -496,26 +568,8 @@ static void zbud_evict_zbpg(struct zbud_page *zbpg) static void zbud_evict_pages(int nr) { struct zbud_page *zbpg; - int i; + int i, newly_unused_pages = 0; - /* first try freeing any pages on unused list */ -retry_unused_list: - spin_lock_bh(&zbpg_unused_list_spinlock); - if (!list_empty(&zbpg_unused_list)) { - /* can't walk list here, since it may change when unlocked */ - zbpg = list_first_entry(&zbpg_unused_list, - struct zbud_page, bud_list); - list_del_init(&zbpg->bud_list); - zcache_zbpg_unused_list_count--; - atomic_dec(&zcache_zbud_curr_raw_pages); - spin_unlock_bh(&zbpg_unused_list_spinlock); - zcache_free_page(zbpg); - zcache_evicted_raw_pages++; - if (--nr <= 0) - goto out; - goto retry_unused_list; - } - spin_unlock_bh(&zbpg_unused_list_spinlock); /* now try freeing unbuddied pages, starting with least space avail */ for (i = 0; i < MAX_CHUNK; i++) { @@ -528,15 +582,15 @@ retry_unbud_list_i: list_for_each_entry(zbpg, &zbud_unbuddied[i].list, bud_list) { if (unlikely(!spin_trylock(&zbpg->lock))) continue; - list_del_init(&zbpg->bud_list); zbud_unbuddied[i].count--; spin_unlock(&zbud_budlists_spinlock); zcache_evicted_unbuddied_pages++; /* want budlists unlocked when doing zbpg eviction */ zbud_evict_zbpg(zbpg); + newly_unused_pages++; local_bh_enable(); if (--nr <= 0) - goto out; + goto evict_unused; goto retry_unbud_list_i; } spin_unlock_bh(&zbud_budlists_spinlock); @@ -547,27 +601,413 @@ retry_bud_list: spin_lock_bh(&zbud_budlists_spinlock); if (list_empty(&zbud_buddied_list)) { spin_unlock_bh(&zbud_budlists_spinlock); - goto out; + goto evict_unused; } list_for_each_entry(zbpg, &zbud_buddied_list, bud_list) { if (unlikely(!spin_trylock(&zbpg->lock))) continue; - list_del_init(&zbpg->bud_list); zcache_zbud_buddied_count--; spin_unlock(&zbud_budlists_spinlock); zcache_evicted_buddied_pages++; /* want budlists unlocked when doing zbpg eviction */ zbud_evict_zbpg(zbpg); + newly_unused_pages++; local_bh_enable(); if (--nr <= 0) - goto out; + goto evict_unused; goto retry_bud_list; } spin_unlock_bh(&zbud_budlists_spinlock); + +evict_unused: + return; +} + +static DEFINE_PER_CPU(unsigned char *, zcache_remoteputmem); + +static int zbud_remotify_zbud(struct tmem_xhandle *xh, char *data, + size_t size) +{ + struct tmem_pool *pool; + int i, remotenode, ret = -1; + unsigned char cksum, *p; + unsigned long flags; + + for (p = data, cksum = 0, i = 0; i < size; i++) + cksum += *p; + ret = ramster_remote_put(xh, data, size, true, &remotenode); + if (ret == 0) { + /* data was successfully remoted so change the local version + * to point to the remote node where it landed */ + pool = zcache_get_pool_by_id(LOCAL_CLIENT, xh->pool_id); + BUG_ON(pool == NULL); + local_irq_save(flags); + /* tmem_replace will also free up any local space */ + (void)tmem_replace(pool, &xh->oid, xh->index, + pampd_make_remote(remotenode, size, cksum)); + local_irq_restore(flags); + zcache_put_pool(pool); + ramster_eph_pages_remoted++; + ret = 0; + } else + ramster_eph_pages_remote_failed++; + return ret; +} + +static int zbud_remotify_zbpg(struct zbud_page *zbpg) +{ + struct zbud_hdr *zh1, *zh2 = NULL; + struct tmem_xhandle xh1, xh2 = { 0 }; + char *data1 = NULL, *data2 = NULL; + size_t size1 = 0, size2 = 0; + int ret = 0; + unsigned char *tmpmem = __get_cpu_var(zcache_remoteputmem); + + ASSERT_SPINLOCK(&zbpg->lock); + if (zbpg->buddy[0].size == 0) + zh1 = &zbpg->buddy[1]; + else if (zbpg->buddy[1].size == 0) + zh1 = &zbpg->buddy[0]; + else { + zh1 = &zbpg->buddy[0]; + zh2 = &zbpg->buddy[1]; + } + /* don't remotify pages that are already remotified */ + if (zh1->client_id != LOCAL_CLIENT) + zh1 = NULL; + if ((zh2 != NULL) && (zh2->client_id != LOCAL_CLIENT)) + zh2 = NULL; + + /* copy the data and metadata so can release lock */ + if (zh1 != NULL) { + xh1.client_id = zh1->client_id; + xh1.pool_id = zh1->pool_id; + xh1.oid = zh1->oid; + xh1.index = zh1->index; + size1 = zh1->size; + data1 = zbud_data(zh1, size1); + memcpy(tmpmem, zbud_data(zh1, size1), size1); + data1 = tmpmem; + tmpmem += size1; + } + if (zh2 != NULL) { + xh2.client_id = zh2->client_id; + xh2.pool_id = zh2->pool_id; + xh2.oid = zh2->oid; + xh2.index = zh2->index; + size2 = zh2->size; + memcpy(tmpmem, zbud_data(zh2, size2), size2); + data2 = tmpmem; + } + spin_unlock(&zbpg->lock); + preempt_enable(); + + /* OK, no locks held anymore, remotify one or both zbuds */ + if (zh1 != NULL) + ret = zbud_remotify_zbud(&xh1, data1, size1); + if (zh2 != NULL) + ret |= zbud_remotify_zbud(&xh2, data2, size2); + return ret; +} + +void zbud_remotify_pages(int nr) +{ + struct zbud_page *zbpg; + int i, ret; + + /* + * for now just try remotifying unbuddied pages, starting with + * least space avail + */ + for (i = 0; i < MAX_CHUNK; i++) { +retry_unbud_list_i: + preempt_disable(); /* enable in zbud_remotify_zbpg */ + spin_lock_bh(&zbud_budlists_spinlock); + if (list_empty(&zbud_unbuddied[i].list)) { + spin_unlock_bh(&zbud_budlists_spinlock); + preempt_enable(); + continue; /* next i in for loop */ + } + list_for_each_entry(zbpg, &zbud_unbuddied[i].list, bud_list) { + if (unlikely(!spin_trylock(&zbpg->lock))) + continue; /* next list_for_each_entry */ + zbud_unbuddied[i].count--; + /* want budlists unlocked when doing zbpg remotify */ + spin_unlock_bh(&zbud_budlists_spinlock); + ret = zbud_remotify_zbpg(zbpg); + /* preemption is re-enabled in zbud_remotify_zbpg */ + if (ret == 0) { + if (--nr <= 0) + goto out; + goto retry_unbud_list_i; + } + /* if fail to remotify any page, quit */ + pr_err("TESTING zbud_remotify_pages failed on page," + " trying to re-add\n"); + spin_lock_bh(&zbud_budlists_spinlock); + spin_lock(&zbpg->lock); + list_add_tail(&zbpg->bud_list, &zbud_unbuddied[i].list); + zbud_unbuddied[i].count++; + spin_unlock(&zbpg->lock); + spin_unlock_bh(&zbud_budlists_spinlock); + pr_err("TESTING zbud_remotify_pages failed on page," + " finished re-add\n"); + goto out; + } + spin_unlock_bh(&zbud_budlists_spinlock); + preempt_enable(); + } + +next_buddied_zbpg: + preempt_disable(); /* enable in zbud_remotify_zbpg */ + spin_lock_bh(&zbud_budlists_spinlock); + if (list_empty(&zbud_buddied_list)) + goto unlock_out; + list_for_each_entry(zbpg, &zbud_buddied_list, bud_list) { + if (unlikely(!spin_trylock(&zbpg->lock))) + continue; /* next list_for_each_entry */ + zcache_zbud_buddied_count--; + /* want budlists unlocked when doing zbpg remotify */ + spin_unlock_bh(&zbud_budlists_spinlock); + ret = zbud_remotify_zbpg(zbpg); + /* preemption is re-enabled in zbud_remotify_zbpg */ + if (ret == 0) { + if (--nr <= 0) + goto out; + goto next_buddied_zbpg; + } + /* if fail to remotify any page, quit */ + pr_err("TESTING zbud_remotify_pages failed on BUDDIED page," + " trying to re-add\n"); + spin_lock_bh(&zbud_budlists_spinlock); + spin_lock(&zbpg->lock); + list_add_tail(&zbpg->bud_list, &zbud_buddied_list); + zcache_zbud_buddied_count++; + spin_unlock(&zbpg->lock); + spin_unlock_bh(&zbud_budlists_spinlock); + pr_err("TESTING zbud_remotify_pages failed on BUDDIED page," + " finished re-add\n"); + goto out; + } +unlock_out: + spin_unlock_bh(&zbud_budlists_spinlock); + preempt_enable(); out: return; } +/* the "flush list" asynchronously collects pages to remotely flush */ +#define FLUSH_ENTIRE_OBJECT ((uint32_t)-1) +static void ramster_flnode_free(struct flushlist_node *, + struct tmem_pool *); + +static void zcache_remote_flush_page(struct flushlist_node *flnode) +{ + struct tmem_xhandle *xh; + int remotenode, ret; + + preempt_disable(); + xh = &flnode->xh; + remotenode = flnode->xh.client_id; + ret = ramster_remote_flush(xh, remotenode); + if (ret >= 0) + ramster_remote_pages_flushed++; + else + ramster_remote_page_flushes_failed++; + preempt_enable_no_resched(); + ramster_flnode_free(flnode, NULL); +} + +static void zcache_remote_flush_object(struct flushlist_node *flnode) +{ + struct tmem_xhandle *xh; + int remotenode, ret; + + preempt_disable(); + xh = &flnode->xh; + remotenode = flnode->xh.client_id; + ret = ramster_remote_flush_object(xh, remotenode); + if (ret >= 0) + ramster_remote_objects_flushed++; + else + ramster_remote_object_flushes_failed++; + preempt_enable_no_resched(); + ramster_flnode_free(flnode, NULL); +} + +static void zcache_remote_eph_put(struct zbud_hdr *zbud) +{ + /* FIXME */ +} + +static void zcache_remote_pers_put(struct zv_hdr *zv) +{ + struct tmem_xhandle xh; + uint16_t size; + bool ephemeral; + int remotenode, ret = -1; + char *data; + struct tmem_pool *pool; + unsigned long flags; + unsigned char cksum; + char *p; + int i; + unsigned char *tmpmem = __get_cpu_var(zcache_remoteputmem); + + ASSERT_SENTINEL(zv, ZVH); + BUG_ON(zv->client_id != LOCAL_CLIENT); + local_bh_disable(); + xh.client_id = zv->client_id; + xh.pool_id = zv->pool_id; + xh.oid = zv->oid; + xh.index = zv->index; + size = xv_get_object_size(zv) - sizeof(*zv); + BUG_ON(size == 0 || size > zv_max_page_size); + data = (char *)zv + sizeof(*zv); + for (p = data, cksum = 0, i = 0; i < size; i++) + cksum += *p; + memcpy(tmpmem, data, size); + data = tmpmem; + pool = zcache_get_pool_by_id(zv->client_id, zv->pool_id); + ephemeral = is_ephemeral(pool); + zcache_put_pool(pool); + /* now OK to release lock set in caller */ + spin_unlock(&zcache_rem_op_list_lock); + local_bh_enable(); + preempt_disable(); + ret = ramster_remote_put(&xh, data, size, ephemeral, &remotenode); + preempt_enable_no_resched(); + if (ret != 0) { + /* + * This is some form of a memory leak... if the remote put + * fails, there will never be another attempt to remotify + * this page. But since we've dropped the zv pointer, + * the page may have been freed or the data replaced + * so we can't just "put it back" in the remote op list. + * Even if we could, not sure where to put it in the list + * because there may be flushes that must be strictly + * ordered vs the put. So leave this as a FIXME for now. + * But count them so we know if it becomes a problem. + */ + ramster_pers_pages_remote_failed++; + goto out; + } else + atomic_inc(&ramster_remote_pers_pages); + ramster_pers_pages_remoted++; + /* + * data was successfully remoted so change the local version to + * point to the remote node where it landed + */ + local_bh_disable(); + pool = zcache_get_pool_by_id(LOCAL_CLIENT, xh.pool_id); + local_irq_save(flags); + (void)tmem_replace(pool, &xh.oid, xh.index, + pampd_make_remote(remotenode, size, cksum)); + local_irq_restore(flags); + zcache_put_pool(pool); + local_bh_enable(); +out: + return; +} + +static void zcache_do_remotify_ops(int nr) +{ + struct ramster_remotify_hdr *rem_op; + union remotify_list_node *u; + + while (1) { + if (!nr) + goto out; + spin_lock(&zcache_rem_op_list_lock); + if (list_empty(&zcache_rem_op_list)) { + spin_unlock(&zcache_rem_op_list_lock); + goto out; + } + rem_op = list_first_entry(&zcache_rem_op_list, + struct ramster_remotify_hdr, list); + list_del_init(&rem_op->list); + if (rem_op->op != RAMSTER_REMOTIFY_PERS_PUT) + spin_unlock(&zcache_rem_op_list_lock); + u = (union remotify_list_node *)rem_op; + switch (rem_op->op) { + case RAMSTER_REMOTIFY_EPH_PUT: +BUG(); + zcache_remote_eph_put((struct zbud_hdr *)rem_op); + break; + case RAMSTER_REMOTIFY_PERS_PUT: + zcache_remote_pers_put((struct zv_hdr *)rem_op); + break; + case RAMSTER_REMOTIFY_FLUSH_PAGE: + zcache_remote_flush_page((struct flushlist_node *)u); + break; + case RAMSTER_REMOTIFY_FLUSH_OBJ: + zcache_remote_flush_object((struct flushlist_node *)u); + break; + default: + BUG(); + } + } +out: + return; +} + +/* + * Communicate interface revision with userspace + */ +#include "cluster/ramster_nodemanager.h" +static unsigned long ramster_interface_revision = R2NM_API_VERSION; + +/* + * For now, just push over a few pages every few seconds to + * ensure that it basically works + */ +static struct workqueue_struct *ramster_remotify_workqueue; +static void ramster_remotify_process(struct work_struct *work); +static DECLARE_DELAYED_WORK(ramster_remotify_worker, + ramster_remotify_process); + +static void ramster_remotify_queue_delayed_work(unsigned long delay) +{ + if (!queue_delayed_work(ramster_remotify_workqueue, + &ramster_remotify_worker, delay)) + pr_err("ramster_remotify: bad workqueue\n"); +} + + +static int use_frontswap; +static int use_cleancache; +static int ramster_remote_target_nodenum = -1; +static void ramster_remotify_process(struct work_struct *work) +{ + static bool remotify_in_progress; + + BUG_ON(irqs_disabled()); + if (remotify_in_progress) + ramster_remotify_queue_delayed_work(HZ); + else if (ramster_remote_target_nodenum != -1) { + remotify_in_progress = true; +#ifdef CONFIG_CLEANCACHE + if (use_cleancache && ramster_eph_remotify_enable) + zbud_remotify_pages(5000); /* FIXME is this a good number? */ +#endif +#ifdef CONFIG_FRONTSWAP + if (use_frontswap && ramster_pers_remotify_enable) + zcache_do_remotify_ops(500); /* FIXME is this a good number? */ +#endif + remotify_in_progress = false; + ramster_remotify_queue_delayed_work(HZ); + } +} + +static void ramster_remotify_init(void) +{ + unsigned long n = 60UL; + ramster_remotify_workqueue = + create_singlethread_workqueue("ramster_remotify"); + ramster_remotify_queue_delayed_work(n * HZ); +} + + static void zbud_init(void) { int i; @@ -631,15 +1071,6 @@ static int zbud_show_cumul_chunk_counts(char *buf) * necessary for decompression) immediately preceding the compressed data. */ -#define ZVH_SENTINEL 0x43214321 - -struct zv_hdr { - uint32_t pool_id; - struct tmem_oid oid; - uint32_t index; - DECL_SENTINEL -}; - /* rudimentary policy limits */ /* total number of persistent pages may not exceed this percentage */ static unsigned int zv_page_count_policy_percent = 75; @@ -655,10 +1086,11 @@ static unsigned int zv_max_zsize = (PAGE_SIZE / 8) * 7; */ static unsigned int zv_max_mean_zsize = (PAGE_SIZE / 8) * 5; -static unsigned long zv_curr_dist_counts[NCHUNKS]; -static unsigned long zv_cumul_dist_counts[NCHUNKS]; +static atomic_t zv_curr_dist_counts[NCHUNKS]; +static atomic_t zv_cumul_dist_counts[NCHUNKS]; -static struct zv_hdr *zv_create(struct xv_pool *xvpool, uint32_t pool_id, + +static struct zv_hdr *zv_create(struct zcache_client *cli, uint32_t pool_id, struct tmem_oid *oid, uint32_t index, void *cdata, unsigned clen) { @@ -671,23 +1103,61 @@ static struct zv_hdr *zv_create(struct xv_pool *xvpool, uint32_t pool_id, BUG_ON(!irqs_disabled()); BUG_ON(chunks >= NCHUNKS); - ret = xv_malloc(xvpool, alloc_size, + ret = xv_malloc(cli->xvpool, clen + sizeof(struct zv_hdr), &page, &offset, ZCACHE_GFP_MASK); if (unlikely(ret)) goto out; - zv_curr_dist_counts[chunks]++; - zv_cumul_dist_counts[chunks]++; + atomic_inc(&zv_curr_dist_counts[chunks]); + atomic_inc(&zv_cumul_dist_counts[chunks]); zv = kmap_atomic(page, KM_USER0) + offset; zv->index = index; zv->oid = *oid; zv->pool_id = pool_id; SET_SENTINEL(zv, ZVH); + INIT_LIST_HEAD(&zv->rem_op.list); + zv->client_id = get_client_id_from_client(cli); + zv->rem_op.op = RAMSTER_REMOTIFY_PERS_PUT; + if (zv->client_id == LOCAL_CLIENT) { + spin_lock(&zcache_rem_op_list_lock); + list_add_tail(&zv->rem_op.list, &zcache_rem_op_list); + spin_unlock(&zcache_rem_op_list_lock); + } memcpy((char *)zv + sizeof(struct zv_hdr), cdata, clen); kunmap_atomic(zv, KM_USER0); out: return zv; } +/* similar to zv_create, but just reserve space, no data yet */ +static struct zv_hdr *zv_alloc(struct tmem_pool *pool, + struct tmem_oid *oid, uint32_t index, + unsigned clen) +{ + struct zcache_client *cli = pool->client; + struct page *page; + struct zv_hdr *zv = NULL; + uint32_t offset; + int ret; + + BUG_ON(!irqs_disabled()); + BUG_ON(!is_local_client(pool->client)); + ret = xv_malloc(cli->xvpool, clen + sizeof(struct zv_hdr), + &page, &offset, ZCACHE_GFP_MASK); + if (unlikely(ret)) + goto out; + zv = kmap_atomic(page, KM_USER0) + offset; + SET_SENTINEL(zv, ZVH); + INIT_LIST_HEAD(&zv->rem_op.list); + zv->client_id = LOCAL_CLIENT; + zv->rem_op.op = RAMSTER_INTRANSIT_PERS; + zv->index = index; + zv->oid = *oid; + zv->pool_id = pool->pool_id; + kunmap_atomic(zv, KM_USER0); +out: + return zv; +} + static void zv_free(struct xv_pool *xvpool, struct zv_hdr *zv) { unsigned long flags; @@ -698,10 +1168,15 @@ static void zv_free(struct xv_pool *xvpool, struct zv_hdr *zv) ASSERT_SENTINEL(zv, ZVH); BUG_ON(chunks >= NCHUNKS); - zv_curr_dist_counts[chunks]--; + atomic_dec(&zv_curr_dist_counts[chunks]); size -= sizeof(*zv); + spin_lock(&zcache_rem_op_list_lock); + size = xv_get_object_size(zv) - sizeof(*zv); BUG_ON(size == 0); INVERT_SENTINEL(zv, ZVH); + if (!list_empty(&zv->rem_op.list)) + list_del_init(&zv->rem_op.list); + spin_unlock(&zcache_rem_op_list_lock); page = virt_to_page(zv); offset = (unsigned long)zv & ~PAGE_MASK; local_irq_save(flags); @@ -727,6 +1202,29 @@ static void zv_decompress(struct page *page, struct zv_hdr *zv) BUG_ON(clen != PAGE_SIZE); } +static void zv_copy_from_pampd(char *data, size_t *bufsize, struct zv_hdr *zv) +{ + unsigned size; + + ASSERT_SENTINEL(zv, ZVH); + size = xv_get_object_size(zv) - sizeof(*zv); + BUG_ON(size == 0 || size > zv_max_page_size); + BUG_ON(size > *bufsize); + memcpy(data, (char *)zv + sizeof(*zv), size); + *bufsize = size; +} + +static void zv_copy_to_pampd(struct zv_hdr *zv, char *data, size_t size) +{ + unsigned zv_size; + + ASSERT_SENTINEL(zv, ZVH); + zv_size = xv_get_object_size(zv) - sizeof(*zv); + BUG_ON(zv_size != size); + BUG_ON(zv_size == 0 || zv_size > zv_max_page_size); + memcpy((char *)zv + sizeof(*zv), data, size); +} + #ifdef CONFIG_SYSFS /* * show a distribution of compression stats for zv pages. @@ -738,7 +1236,7 @@ static int zv_curr_dist_counts_show(char *buf) char *p = buf; for (i = 0; i < NCHUNKS; i++) { - n = zv_curr_dist_counts[i]; + n = atomic_read(&zv_curr_dist_counts[i]); p += sprintf(p, "%lu ", n); chunks += n; sum_total_chunks += i * n; @@ -754,7 +1252,7 @@ static int zv_cumul_dist_counts_show(char *buf) char *p = buf; for (i = 0; i < NCHUNKS; i++) { - n = zv_cumul_dist_counts[i]; + n = atomic_read(&zv_cumul_dist_counts[i]); p += sprintf(p, "%lu ", n); chunks += n; sum_total_chunks += i * n; @@ -787,7 +1285,7 @@ static ssize_t zv_max_zsize_store(struct kobject *kobj, if (!capable(CAP_SYS_ADMIN)) return -EPERM; - err = strict_strtoul(buf, 10, &val); + err = kstrtoul(buf, 10, &val); if (err || (val == 0) || (val > (PAGE_SIZE / 8) * 7)) return -EINVAL; zv_max_zsize = val; @@ -819,7 +1317,7 @@ static ssize_t zv_max_mean_zsize_store(struct kobject *kobj, if (!capable(CAP_SYS_ADMIN)) return -EPERM; - err = strict_strtoul(buf, 10, &val); + err = kstrtoul(buf, 10, &val); if (err || (val == 0) || (val > (PAGE_SIZE / 8) * 7)) return -EINVAL; zv_max_mean_zsize = val; @@ -853,7 +1351,7 @@ static ssize_t zv_page_count_policy_percent_store(struct kobject *kobj, if (!capable(CAP_SYS_ADMIN)) return -EPERM; - err = strict_strtoul(buf, 10, &val); + err = kstrtoul(buf, 10, &val); if (err || (val == 0) || (val > 150)) return -EINVAL; zv_page_count_policy_percent = val; @@ -890,6 +1388,7 @@ static unsigned long zcache_flush_found; static unsigned long zcache_flobj_total; static unsigned long zcache_flobj_found; static unsigned long zcache_failed_eph_puts; +static unsigned long zcache_nonactive_puts; static unsigned long zcache_failed_pers_puts; /* @@ -970,6 +1469,7 @@ static unsigned long zcache_put_to_flush; */ static struct kmem_cache *zcache_objnode_cache; static struct kmem_cache *zcache_obj_cache; +static struct kmem_cache *ramster_flnode_cache; static atomic_t zcache_curr_obj_count = ATOMIC_INIT(0); static unsigned long zcache_curr_obj_count_max; static atomic_t zcache_curr_objnode_count = ATOMIC_INIT(0); @@ -985,6 +1485,7 @@ struct zcache_preload { struct tmem_obj *obj; int nr; struct tmem_objnode *objnodes[OBJNODE_TREE_MAX_PATH]; + struct flushlist_node *flnode; }; static DEFINE_PER_CPU(struct zcache_preload, zcache_preloads) = { 0, }; @@ -993,6 +1494,7 @@ static int zcache_do_preload(struct tmem_pool *pool) struct zcache_preload *kp; struct tmem_objnode *objnode; struct tmem_obj *obj; + struct flushlist_node *flnode; void *page; int ret = -ENOMEM; @@ -1023,27 +1525,61 @@ static int zcache_do_preload(struct tmem_pool *pool) zcache_failed_alloc++; goto out; } - page = (void *)__get_free_page(ZCACHE_GFP_MASK); - if (unlikely(page == NULL)) { - zcache_failed_get_free_pages++; - kmem_cache_free(zcache_obj_cache, obj); + flnode = kmem_cache_alloc(ramster_flnode_cache, ZCACHE_GFP_MASK); + if (unlikely(flnode == NULL)) { + zcache_failed_alloc++; goto out; } + if (is_ephemeral(pool)) { + page = (void *)__get_free_page(ZCACHE_GFP_MASK); + if (unlikely(page == NULL)) { + zcache_failed_get_free_pages++; + kmem_cache_free(zcache_obj_cache, obj); + kmem_cache_free(ramster_flnode_cache, flnode); + goto out; + } + } preempt_disable(); kp = &__get_cpu_var(zcache_preloads); if (kp->obj == NULL) kp->obj = obj; else kmem_cache_free(zcache_obj_cache, obj); - if (kp->page == NULL) - kp->page = page; + if (kp->flnode == NULL) + kp->flnode = flnode; else - free_page((unsigned long)page); + kmem_cache_free(ramster_flnode_cache, flnode); + if (is_ephemeral(pool)) { + if (kp->page == NULL) + kp->page = page; + else + free_page((unsigned long)page); + } ret = 0; out: return ret; } +static int ramster_do_preload_flnode_only(struct tmem_pool *pool) +{ + struct zcache_preload *kp; + struct flushlist_node *flnode; + int ret = -ENOMEM; + + BUG_ON(!irqs_disabled()); + if (unlikely(ramster_flnode_cache == NULL)) + BUG(); + kp = &__get_cpu_var(zcache_preloads); + flnode = kmem_cache_alloc(ramster_flnode_cache, GFP_ATOMIC); + if (unlikely(flnode == NULL) && kp->flnode == NULL) + BUG(); /* FIXME handle more gracefully, but how??? */ + else if (kp->flnode == NULL) + kp->flnode = flnode; + else + kmem_cache_free(ramster_flnode_cache, flnode); + return ret; +} + static void *zcache_get_free_page(void) { struct zcache_preload *kp; @@ -1116,6 +1652,30 @@ static void zcache_obj_free(struct tmem_obj *obj, struct tmem_pool *pool) kmem_cache_free(zcache_obj_cache, obj); } +static struct flushlist_node *ramster_flnode_alloc(struct tmem_pool *pool) +{ + struct flushlist_node *flnode = NULL; + struct zcache_preload *kp; + int count; + + kp = &__get_cpu_var(zcache_preloads); + flnode = kp->flnode; + BUG_ON(flnode == NULL); + kp->flnode = NULL; + count = atomic_inc_return(&ramster_curr_flnode_count); + if (count > ramster_curr_flnode_count_max) + ramster_curr_flnode_count_max = count; + return flnode; +} + +static void ramster_flnode_free(struct flushlist_node *flnode, + struct tmem_pool *pool) +{ + atomic_dec(&ramster_curr_flnode_count); + BUG_ON(atomic_read(&ramster_curr_flnode_count) < 0); + kmem_cache_free(ramster_flnode_cache, flnode); +} + static struct tmem_hostops zcache_hostops = { .obj_alloc = zcache_obj_alloc, .obj_free = zcache_obj_free, @@ -1127,6 +1687,14 @@ static struct tmem_hostops zcache_hostops = { * zcache implementations for PAM page descriptor ops */ + +static inline void dec_and_check(atomic_t *pvar) +{ + atomic_dec(pvar); + /* later when all accounting is fixed, make this a BUG */ + WARN_ON_ONCE(atomic_read(pvar) < 0); +} + static atomic_t zcache_curr_eph_pampd_count = ATOMIC_INIT(0); static unsigned long zcache_curr_eph_pampd_count_max; static atomic_t zcache_curr_pers_pampd_count = ATOMIC_INIT(0); @@ -1135,22 +1703,20 @@ static unsigned long zcache_curr_pers_pampd_count_max; /* forward reference */ static int zcache_compress(struct page *from, void **out_va, size_t *out_len); -static void *zcache_pampd_create(char *data, size_t size, bool raw, int eph, +static int zcache_pampd_eph_create(char *data, size_t size, bool raw, struct tmem_pool *pool, struct tmem_oid *oid, - uint32_t index) + uint32_t index, void **pampd) { - void *pampd = NULL, *cdata; - size_t clen; - int ret; - unsigned long count; - struct page *page = (struct page *)(data); + int ret = -1; + void *cdata = data; + size_t clen = size; struct zcache_client *cli = pool->client; uint16_t client_id = get_client_id_from_client(cli); - unsigned long zv_mean_zsize; - unsigned long curr_pers_pampd_count; - u64 total_zsize; + struct page *page = NULL; + unsigned long count; - if (eph) { + if (!raw) { + page = virt_to_page(data); ret = zcache_compress(page, &cdata, &clen); if (ret == 0) goto out; @@ -1158,46 +1724,114 @@ static void *zcache_pampd_create(char *data, size_t size, bool raw, int eph, zcache_compress_poor++; goto out; } - pampd = (void *)zbud_create(client_id, pool->pool_id, oid, - index, page, cdata, clen); - if (pampd != NULL) { - count = atomic_inc_return(&zcache_curr_eph_pampd_count); - if (count > zcache_curr_eph_pampd_count_max) - zcache_curr_eph_pampd_count_max = count; - } - } else { - curr_pers_pampd_count = - atomic_read(&zcache_curr_pers_pampd_count); - if (curr_pers_pampd_count > - (zv_page_count_policy_percent * totalram_pages) / 100) - goto out; - ret = zcache_compress(page, &cdata, &clen); - if (ret == 0) - goto out; - /* reject if compression is too poor */ - if (clen > zv_max_zsize) { - zcache_compress_poor++; + } + *pampd = (void *)zbud_create(client_id, pool->pool_id, oid, + index, page, cdata, clen); + if (*pampd == NULL) { + ret = -ENOMEM; + goto out; + } + ret = 0; + count = atomic_inc_return(&zcache_curr_eph_pampd_count); + if (count > zcache_curr_eph_pampd_count_max) + zcache_curr_eph_pampd_count_max = count; + if (client_id != LOCAL_CLIENT) { + count = atomic_inc_return(&ramster_foreign_eph_pampd_count); + if (count > ramster_foreign_eph_pampd_count_max) + ramster_foreign_eph_pampd_count_max = count; + } +out: + return ret; +} + +static int zcache_pampd_pers_create(char *data, size_t size, bool raw, + struct tmem_pool *pool, struct tmem_oid *oid, + uint32_t index, void **pampd) +{ + int ret = -1; + void *cdata = data; + size_t clen = size; + struct zcache_client *cli = pool->client; + struct page *page; + unsigned long count; + unsigned long zv_mean_zsize; + struct zv_hdr *zv; + long curr_pers_pampd_count; + u64 total_zsize; +#ifdef RAMSTER_TESTING + static bool pampd_neg_warned; +#endif + + curr_pers_pampd_count = atomic_read(&zcache_curr_pers_pampd_count) - + atomic_read(&ramster_remote_pers_pages); +#ifdef RAMSTER_TESTING + /* should always be positive, but warn if accounting is off */ + if (!pampd_neg_warned) { + pr_warn("ramster: bad accounting for curr_pers_pampd_count\n"); + pampd_neg_warned = true; + } +#endif + if (curr_pers_pampd_count > + (zv_page_count_policy_percent * totalram_pages) / 100) { + zcache_policy_percent_exceeded++; + goto out; + } + if (raw) + goto ok_to_create; + page = virt_to_page(data); + if (zcache_compress(page, &cdata, &clen) == 0) + goto out; + /* reject if compression is too poor */ + if (clen > zv_max_zsize) { + zcache_compress_poor++; + goto out; + } + /* reject if mean compression is too poor */ + if ((clen > zv_max_mean_zsize) && (curr_pers_pampd_count > 0)) { + total_zsize = xv_get_total_size_bytes(cli->xvpool); + zv_mean_zsize = div_u64(total_zsize, curr_pers_pampd_count); + if (zv_mean_zsize > zv_max_mean_zsize) { + zcache_mean_compress_poor++; goto out; } - /* reject if mean compression is too poor */ - if ((clen > zv_max_mean_zsize) && (curr_pers_pampd_count > 0)) { - total_zsize = xv_get_total_size_bytes(cli->xvpool); - zv_mean_zsize = div_u64(total_zsize, - curr_pers_pampd_count); - if (zv_mean_zsize > zv_max_mean_zsize) { - zcache_mean_compress_poor++; - goto out; - } - } - pampd = (void *)zv_create(cli->xvpool, pool->pool_id, - oid, index, cdata, clen); - if (pampd == NULL) - goto out; - count = atomic_inc_return(&zcache_curr_pers_pampd_count); - if (count > zcache_curr_pers_pampd_count_max) - zcache_curr_pers_pampd_count_max = count; } +ok_to_create: + *pampd = (void *)zv_create(cli, pool->pool_id, oid, index, cdata, clen); + if (*pampd == NULL) { + ret = -ENOMEM; + goto out; + } + ret = 0; + count = atomic_inc_return(&zcache_curr_pers_pampd_count); + if (count > zcache_curr_pers_pampd_count_max) + zcache_curr_pers_pampd_count_max = count; + if (is_local_client(cli)) + goto out; + zv = *(struct zv_hdr **)pampd; + count = atomic_inc_return(&ramster_foreign_pers_pampd_count); + if (count > ramster_foreign_pers_pampd_count_max) + ramster_foreign_pers_pampd_count_max = count; out: + return ret; +} + +static void *zcache_pampd_create(char *data, size_t size, bool raw, int eph, + struct tmem_pool *pool, struct tmem_oid *oid, + uint32_t index) +{ + void *pampd = NULL; + int ret; + bool ephemeral; + + BUG_ON(preemptible()); + ephemeral = (eph == 1) || ((eph == 0) && is_ephemeral(pool)); + if (ephemeral) + ret = zcache_pampd_eph_create(data, size, raw, pool, + oid, index, &pampd); + else + ret = zcache_pampd_pers_create(data, size, raw, pool, + oid, index, &pampd); + /* FIXME add some counters here for failed creates? */ return pampd; } @@ -1211,75 +1845,343 @@ static int zcache_pampd_get_data(char *data, size_t *bufsize, bool raw, { int ret = 0; - BUG_ON(is_ephemeral(pool)); - zv_decompress((struct page *)(data), pampd); - return ret; -} - -/* - * fill the pageframe corresponding to the struct page with the data - * from the passed pampd - */ + BUG_ON(preemptible()); + BUG_ON(is_ephemeral(pool)); /* Fix later for shared pools? */ + BUG_ON(pampd_is_remote(pampd)); + if (raw) + zv_copy_from_pampd(data, bufsize, pampd); + else + zv_decompress(virt_to_page(data), pampd); + return ret; +} + static int zcache_pampd_get_data_and_free(char *data, size_t *bufsize, bool raw, void *pampd, struct tmem_pool *pool, struct tmem_oid *oid, uint32_t index) { int ret = 0; + unsigned long flags; + struct zcache_client *cli = pool->client; - BUG_ON(!is_ephemeral(pool)); - zbud_decompress((struct page *)(data), pampd); - zbud_free_and_delist((struct zbud_hdr *)pampd); - atomic_dec(&zcache_curr_eph_pampd_count); + BUG_ON(preemptible()); + BUG_ON(pampd_is_remote(pampd)); + if (is_ephemeral(pool)) { + local_irq_save(flags); + if (raw) + zbud_copy_from_pampd(data, bufsize, pampd); + else + ret = zbud_decompress(virt_to_page(data), pampd); + zbud_free_and_delist((struct zbud_hdr *)pampd); + local_irq_restore(flags); + if (!is_local_client(cli)) + dec_and_check(&ramster_foreign_eph_pampd_count); + dec_and_check(&zcache_curr_eph_pampd_count); + } else { + if (is_local_client(cli)) + BUG(); + if (raw) + zv_copy_from_pampd(data, bufsize, pampd); + else + zv_decompress(virt_to_page(data), pampd); + zv_free(cli->xvpool, pampd); + if (!is_local_client(cli)) + dec_and_check(&ramster_foreign_pers_pampd_count); + dec_and_check(&zcache_curr_pers_pampd_count); + ret = 0; + } return ret; } +static bool zcache_pampd_is_remote(void *pampd) +{ + return pampd_is_remote(pampd); +} + /* * free the pampd and remove it from any zcache lists * pampd must no longer be pointed to from any tmem data structures! */ static void zcache_pampd_free(void *pampd, struct tmem_pool *pool, - struct tmem_oid *oid, uint32_t index) + struct tmem_oid *oid, uint32_t index, bool acct) { struct zcache_client *cli = pool->client; - - if (is_ephemeral(pool)) { + bool eph = is_ephemeral(pool); + struct zv_hdr *zv; + + BUG_ON(preemptible()); + if (pampd_is_remote(pampd)) { + WARN_ON(acct == false); + if (oid == NULL) { + /* + * a NULL oid means to ignore this pampd free + * as the remote freeing will be handled elsewhere + */ + } else if (eph) { + /* FIXME remote flush optional but probably good idea */ + /* FIXME get these working properly again */ + dec_and_check(&zcache_curr_eph_pampd_count); + } else if (pampd_is_intransit(pampd)) { + /* did a pers remote get_and_free, so just free local */ + pampd = pampd_mask_intransit_and_remote(pampd); + goto local_pers; + } else { + struct flushlist_node *flnode = + ramster_flnode_alloc(pool); + + flnode->xh.client_id = pampd_remote_node(pampd); + flnode->xh.pool_id = pool->pool_id; + flnode->xh.oid = *oid; + flnode->xh.index = index; + flnode->rem_op.op = RAMSTER_REMOTIFY_FLUSH_PAGE; + spin_lock(&zcache_rem_op_list_lock); + list_add(&flnode->rem_op.list, &zcache_rem_op_list); + spin_unlock(&zcache_rem_op_list_lock); + dec_and_check(&zcache_curr_pers_pampd_count); + dec_and_check(&ramster_remote_pers_pages); + } + } else if (eph) { zbud_free_and_delist((struct zbud_hdr *)pampd); - atomic_dec(&zcache_curr_eph_pampd_count); - BUG_ON(atomic_read(&zcache_curr_eph_pampd_count) < 0); + if (!is_local_client(pool->client)) + dec_and_check(&ramster_foreign_eph_pampd_count); + if (acct) + /* FIXME get these working properly again */ + dec_and_check(&zcache_curr_eph_pampd_count); } else { - zv_free(cli->xvpool, (struct zv_hdr *)pampd); - atomic_dec(&zcache_curr_pers_pampd_count); - BUG_ON(atomic_read(&zcache_curr_pers_pampd_count) < 0); +local_pers: + zv = (struct zv_hdr *)pampd; + if (!is_local_client(pool->client)) + dec_and_check(&ramster_foreign_pers_pampd_count); + zv_free(cli->xvpool, zv); + if (acct) + /* FIXME get these working properly again */ + dec_and_check(&zcache_curr_pers_pampd_count); } } -static void zcache_pampd_free_obj(struct tmem_pool *pool, struct tmem_obj *obj) +static void zcache_pampd_free_obj(struct tmem_pool *pool, + struct tmem_obj *obj) { + struct flushlist_node *flnode; + + BUG_ON(preemptible()); + if (obj->extra == NULL) + return; + BUG_ON(!pampd_is_remote(obj->extra)); + flnode = ramster_flnode_alloc(pool); + flnode->xh.client_id = pampd_remote_node(obj->extra); + flnode->xh.pool_id = pool->pool_id; + flnode->xh.oid = obj->oid; + flnode->xh.index = FLUSH_ENTIRE_OBJECT; + flnode->rem_op.op = RAMSTER_REMOTIFY_FLUSH_OBJ; + spin_lock(&zcache_rem_op_list_lock); + list_add(&flnode->rem_op.list, &zcache_rem_op_list); + spin_unlock(&zcache_rem_op_list_lock); } -static void zcache_pampd_new_obj(struct tmem_obj *obj) +void zcache_pampd_new_obj(struct tmem_obj *obj) { + obj->extra = NULL; } -static int zcache_pampd_replace_in_obj(void *pampd, struct tmem_obj *obj) +int zcache_pampd_replace_in_obj(void *new_pampd, struct tmem_obj *obj) { - return -1; + int ret = -1; + + if (new_pampd != NULL) { + if (obj->extra == NULL) + obj->extra = new_pampd; + /* enforce that all remote pages in an object reside + * in the same node! */ + else if (pampd_remote_node(new_pampd) != + pampd_remote_node((void *)(obj->extra))) + BUG(); + ret = 0; + } + return ret; } -static bool zcache_pampd_is_remote(void *pampd) +/* + * Called by the message handler after a (still compressed) page has been + * fetched from the remote machine in response to an "is_remote" tmem_get + * or persistent tmem_localify. For a tmem_get, "extra" is the address of + * the page that is to be filled to succesfully resolve the tmem_get; for + * a (persistent) tmem_localify, "extra" is NULL (as the data is placed only + * in the local zcache). "data" points to "size" bytes of (compressed) data + * passed in the message. In the case of a persistent remote get, if + * pre-allocation was successful (see zcache_repatriate_preload), the page + * is placed into both local zcache and at "extra". + */ +int zcache_localify(int pool_id, struct tmem_oid *oidp, + uint32_t index, char *data, size_t size, + void *extra) { - return 0; + int ret = -ENOENT; + unsigned long flags; + struct tmem_pool *pool; + bool ephemeral, delete = false; + size_t clen = PAGE_SIZE; + void *pampd, *saved_hb; + struct tmem_obj *obj; + + pool = zcache_get_pool_by_id(LOCAL_CLIENT, pool_id); + if (unlikely(pool == NULL)) + /* pool doesn't exist anymore */ + goto out; + ephemeral = is_ephemeral(pool); + local_irq_save(flags); /* FIXME: maybe only disable softirqs? */ + pampd = tmem_localify_get_pampd(pool, oidp, index, &obj, &saved_hb); + if (pampd == NULL) { + /* hmmm... must have been a flush while waiting */ +#ifdef RAMSTER_TESTING + pr_err("UNTESTED pampd==NULL in zcache_localify\n"); +#endif + if (ephemeral) + ramster_remote_eph_pages_unsucc_get++; + else + ramster_remote_pers_pages_unsucc_get++; + obj = NULL; + goto finish; + } else if (unlikely(!pampd_is_remote(pampd))) { + /* hmmm... must have been a dup put while waiting */ +#ifdef RAMSTER_TESTING + pr_err("UNTESTED dup while waiting in zcache_localify\n"); +#endif + if (ephemeral) + ramster_remote_eph_pages_unsucc_get++; + else + ramster_remote_pers_pages_unsucc_get++; + obj = NULL; + pampd = NULL; + ret = -EEXIST; + goto finish; + } else if (size == 0) { + /* no remote data, delete the local is_remote pampd */ + pampd = NULL; + if (ephemeral) + ramster_remote_eph_pages_unsucc_get++; + else + BUG(); + delete = true; + goto finish; + } + if (!ephemeral && pampd_is_intransit(pampd)) { + /* localify to zcache */ + pampd = pampd_mask_intransit_and_remote(pampd); + zv_copy_to_pampd(pampd, data, size); + } else { + pampd = NULL; + obj = NULL; + } + if (extra != NULL) { + /* decompress direct-to-memory to complete remotify */ + ret = lzo1x_decompress_safe((char *)data, size, + (char *)extra, &clen); + BUG_ON(ret != LZO_E_OK); + BUG_ON(clen != PAGE_SIZE); + } + if (ephemeral) + ramster_remote_eph_pages_succ_get++; + else + ramster_remote_pers_pages_succ_get++; + ret = 0; +finish: + tmem_localify_finish(obj, index, pampd, saved_hb, delete); + zcache_put_pool(pool); + local_irq_restore(flags); +out: + return ret; +} + +/* + * Called on a remote persistent tmem_get to attempt to preallocate + * local storage for the data contained in the remote persistent page. + * If succesfully preallocated, returns the pampd, marked as remote and + * in_transit. Else returns NULL. Note that the appropriate tmem data + * structure must be locked. + */ +static void *zcache_pampd_repatriate_preload(void *pampd, + struct tmem_pool *pool, + struct tmem_oid *oid, + uint32_t index, + bool *intransit) +{ + int clen = pampd_remote_size(pampd); + void *ret_pampd = NULL; + unsigned long flags; + + if (!pampd_is_remote(pampd)) + BUG(); + if (is_ephemeral(pool)) + BUG(); + if (pampd_is_intransit(pampd)) { + /* + * to avoid multiple allocations (and maybe a memory leak) + * don't preallocate if already in the process of being + * repatriated + */ + *intransit = true; + goto out; + } + *intransit = false; + local_irq_save(flags); + ret_pampd = (void *)zv_alloc(pool, oid, index, clen); + if (ret_pampd != NULL) { + /* + * a pampd is marked intransit if it is remote and space has + * been allocated for it locally (note, only happens for + * persistent pages, in which case the remote copy is freed) + */ + ret_pampd = pampd_mark_intransit(ret_pampd); + dec_and_check(&ramster_remote_pers_pages); + } else + ramster_pers_pages_remote_nomem++; + local_irq_restore(flags); +out: + return ret_pampd; +} + +/* + * Called on a remote tmem_get to invoke a message to fetch the page. + * Might sleep so no tmem locks can be held. "extra" is passed + * all the way through the round-trip messaging to zcache_localify. + */ +static int zcache_pampd_repatriate(void *fake_pampd, void *real_pampd, + struct tmem_pool *pool, + struct tmem_oid *oid, uint32_t index, + bool free, void *extra) +{ + struct tmem_xhandle xh; + int ret; + + if (pampd_is_intransit(real_pampd)) + /* have local space pre-reserved, so free remote copy */ + free = true; + xh = tmem_xhandle_fill(LOCAL_CLIENT, pool, oid, index); + /* unreliable request/response for now */ + ret = ramster_remote_async_get(&xh, free, + pampd_remote_node(fake_pampd), + pampd_remote_size(fake_pampd), + pampd_remote_cksum(fake_pampd), + extra); +#ifdef RAMSTER_TESTING + if (ret != 0 && ret != -ENOENT) + pr_err("TESTING zcache_pampd_repatriate returns, ret=%d\n", + ret); +#endif + return ret; } static struct tmem_pamops zcache_pamops = { .create = zcache_pampd_create, .get_data = zcache_pampd_get_data, - .get_data_and_free = zcache_pampd_get_data_and_free, .free = zcache_pampd_free, + .get_data_and_free = zcache_pampd_get_data_and_free, .free_obj = zcache_pampd_free_obj, + .is_remote = zcache_pampd_is_remote, + .repatriate_preload = zcache_pampd_repatriate_preload, + .repatriate = zcache_pampd_repatriate, .new_obj = zcache_pampd_new_obj, .replace_in_obj = zcache_pampd_replace_in_obj, - .is_remote = zcache_pampd_is_remote, }; /* @@ -1327,9 +2229,13 @@ static int zcache_cpu_notifier(struct notifier_block *nb, per_cpu(zcache_workmem, cpu) = kzalloc(LZO1X_MEM_COMPRESS, GFP_KERNEL | __GFP_REPEAT); + per_cpu(zcache_remoteputmem, cpu) = + kzalloc(PAGE_SIZE, GFP_KERNEL | __GFP_REPEAT); break; case CPU_DEAD: case CPU_UP_CANCELED: + kfree(per_cpu(zcache_remoteputmem, cpu)); + per_cpu(zcache_remoteputmem, cpu) = NULL; free_pages((unsigned long)per_cpu(zcache_dstmem, cpu), LZO_DSTMEM_PAGE_ORDER); per_cpu(zcache_dstmem, cpu) = NULL; @@ -1346,6 +2252,10 @@ static int zcache_cpu_notifier(struct notifier_block *nb, kmem_cache_free(zcache_obj_cache, kp->obj); kp->obj = NULL; } + if (kp->flnode) { + kmem_cache_free(ramster_flnode_cache, kp->flnode); + kp->flnode = NULL; + } if (kp->page) { free_page((unsigned long)kp->page); kp->page = NULL; @@ -1402,12 +2312,12 @@ ZCACHE_SYSFS_RO(flush_found); ZCACHE_SYSFS_RO(flobj_total); ZCACHE_SYSFS_RO(flobj_found); ZCACHE_SYSFS_RO(failed_eph_puts); +ZCACHE_SYSFS_RO(nonactive_puts); ZCACHE_SYSFS_RO(failed_pers_puts); ZCACHE_SYSFS_RO(zbud_curr_zbytes); ZCACHE_SYSFS_RO(zbud_cumul_zpages); ZCACHE_SYSFS_RO(zbud_cumul_zbytes); ZCACHE_SYSFS_RO(zbud_buddied_count); -ZCACHE_SYSFS_RO(zbpg_unused_list_count); ZCACHE_SYSFS_RO(evicted_raw_pages); ZCACHE_SYSFS_RO(evicted_unbuddied_pages); ZCACHE_SYSFS_RO(evicted_buddied_pages); @@ -1416,6 +2326,7 @@ ZCACHE_SYSFS_RO(failed_alloc); ZCACHE_SYSFS_RO(put_to_flush); ZCACHE_SYSFS_RO(compress_poor); ZCACHE_SYSFS_RO(mean_compress_poor); +ZCACHE_SYSFS_RO(policy_percent_exceeded); ZCACHE_SYSFS_RO_ATOMIC(zbud_curr_raw_pages); ZCACHE_SYSFS_RO_ATOMIC(zbud_curr_zpages); ZCACHE_SYSFS_RO_ATOMIC(curr_obj_count); @@ -1439,7 +2350,9 @@ static struct attribute *zcache_attrs[] = { &zcache_flush_found_attr.attr, &zcache_flobj_found_attr.attr, &zcache_failed_eph_puts_attr.attr, + &zcache_nonactive_puts_attr.attr, &zcache_failed_pers_puts_attr.attr, + &zcache_policy_percent_exceeded_attr.attr, &zcache_compress_poor_attr.attr, &zcache_mean_compress_poor_attr.attr, &zcache_zbud_curr_raw_pages_attr.attr, @@ -1448,7 +2361,6 @@ static struct attribute *zcache_attrs[] = { &zcache_zbud_cumul_zpages_attr.attr, &zcache_zbud_cumul_zbytes_attr.attr, &zcache_zbud_buddied_count_attr.attr, - &zcache_zbpg_unused_list_count_attr.attr, &zcache_evicted_raw_pages_attr.attr, &zcache_evicted_unbuddied_pages_attr.attr, &zcache_evicted_buddied_pages_attr.attr, @@ -1470,6 +2382,202 @@ static struct attribute_group zcache_attr_group = { .name = "zcache", }; +#define RAMSTER_SYSFS_RO(_name) \ + static ssize_t ramster_##_name##_show(struct kobject *kobj, \ + struct kobj_attribute *attr, char *buf) \ + { \ + return sprintf(buf, "%lu\n", ramster_##_name); \ + } \ + static struct kobj_attribute ramster_##_name##_attr = { \ + .attr = { .name = __stringify(_name), .mode = 0444 }, \ + .show = ramster_##_name##_show, \ + } + +#define RAMSTER_SYSFS_RW(_name) \ + static ssize_t ramster_##_name##_show(struct kobject *kobj, \ + struct kobj_attribute *attr, char *buf) \ + { \ + return sprintf(buf, "%lu\n", ramster_##_name); \ + } \ + static ssize_t ramster_##_name##_store(struct kobject *kobj, \ + struct kobj_attribute *attr, const char *buf, size_t count) \ + { \ + int err; \ + unsigned long enable; \ + err = kstrtoul(buf, 10, &enable); \ + if (err) \ + return -EINVAL; \ + ramster_##_name = enable; \ + return count; \ + } \ + static struct kobj_attribute ramster_##_name##_attr = { \ + .attr = { .name = __stringify(_name), .mode = 0644 }, \ + .show = ramster_##_name##_show, \ + .store = ramster_##_name##_store, \ + } + +#define RAMSTER_SYSFS_RO_ATOMIC(_name) \ + static ssize_t ramster_##_name##_show(struct kobject *kobj, \ + struct kobj_attribute *attr, char *buf) \ + { \ + return sprintf(buf, "%d\n", atomic_read(&ramster_##_name)); \ + } \ + static struct kobj_attribute ramster_##_name##_attr = { \ + .attr = { .name = __stringify(_name), .mode = 0444 }, \ + .show = ramster_##_name##_show, \ + } + +RAMSTER_SYSFS_RO(interface_revision); +RAMSTER_SYSFS_RO_ATOMIC(remote_pers_pages); +RAMSTER_SYSFS_RW(pers_remotify_enable); +RAMSTER_SYSFS_RW(eph_remotify_enable); +RAMSTER_SYSFS_RO(eph_pages_remoted); +RAMSTER_SYSFS_RO(eph_pages_remote_failed); +RAMSTER_SYSFS_RO(pers_pages_remoted); +RAMSTER_SYSFS_RO(pers_pages_remote_failed); +RAMSTER_SYSFS_RO(pers_pages_remote_nomem); +RAMSTER_SYSFS_RO(remote_pages_flushed); +RAMSTER_SYSFS_RO(remote_page_flushes_failed); +RAMSTER_SYSFS_RO(remote_objects_flushed); +RAMSTER_SYSFS_RO(remote_object_flushes_failed); +RAMSTER_SYSFS_RO(remote_eph_pages_succ_get); +RAMSTER_SYSFS_RO(remote_eph_pages_unsucc_get); +RAMSTER_SYSFS_RO(remote_pers_pages_succ_get); +RAMSTER_SYSFS_RO(remote_pers_pages_unsucc_get); +RAMSTER_SYSFS_RO_ATOMIC(foreign_eph_pampd_count); +RAMSTER_SYSFS_RO(foreign_eph_pampd_count_max); +RAMSTER_SYSFS_RO_ATOMIC(foreign_pers_pampd_count); +RAMSTER_SYSFS_RO(foreign_pers_pampd_count_max); +RAMSTER_SYSFS_RO_ATOMIC(curr_flnode_count); +RAMSTER_SYSFS_RO(curr_flnode_count_max); + +#define MANUAL_NODES 8 +static bool ramster_nodes_manual_up[MANUAL_NODES]; +static ssize_t ramster_manual_node_up_show(struct kobject *kobj, + struct kobj_attribute *attr, char *buf) +{ + int i; + char *p = buf; + for (i = 0; i < MANUAL_NODES; i++) + if (ramster_nodes_manual_up[i]) + p += sprintf(p, "%d ", i); + p += sprintf(p, "\n"); + return p - buf; +} + +static ssize_t ramster_manual_node_up_store(struct kobject *kobj, + struct kobj_attribute *attr, const char *buf, size_t count) +{ + int err; + unsigned long node_num; + + err = kstrtoul(buf, 10, &node_num); + if (err) { + pr_err("ramster: bad strtoul?\n"); + return -EINVAL; + } + if (node_num >= MANUAL_NODES) { + pr_err("ramster: bad node_num=%lu?\n", node_num); + return -EINVAL; + } + if (ramster_nodes_manual_up[node_num]) { + pr_err("ramster: node %d already up, ignoring\n", + (int)node_num); + } else { + ramster_nodes_manual_up[node_num] = true; + r2net_hb_node_up_manual((int)node_num); + } + return count; +} + +static struct kobj_attribute ramster_manual_node_up_attr = { + .attr = { .name = "manual_node_up", .mode = 0644 }, + .show = ramster_manual_node_up_show, + .store = ramster_manual_node_up_store, +}; + +static ssize_t ramster_remote_target_nodenum_show(struct kobject *kobj, + struct kobj_attribute *attr, char *buf) +{ + if (ramster_remote_target_nodenum == -1UL) + return sprintf(buf, "unset\n"); + else + return sprintf(buf, "%d\n", ramster_remote_target_nodenum); +} + +static ssize_t ramster_remote_target_nodenum_store(struct kobject *kobj, + struct kobj_attribute *attr, const char *buf, size_t count) +{ + int err; + unsigned long node_num; + + err = kstrtoul(buf, 10, &node_num); + if (err) { + pr_err("ramster: bad strtoul?\n"); + return -EINVAL; + } else if (node_num == -1UL) { + pr_err("ramster: disabling all remotification, " + "data may still reside on remote nodes however\n"); + return -EINVAL; + } else if (node_num >= MANUAL_NODES) { + pr_err("ramster: bad node_num=%lu?\n", node_num); + return -EINVAL; + } else if (!ramster_nodes_manual_up[node_num]) { + pr_err("ramster: node %d not up, ignoring setting " + "of remotification target\n", (int)node_num); + } else if (r2net_remote_target_node_set((int)node_num) >= 0) { + pr_info("ramster: node %d set as remotification target\n", + (int)node_num); + ramster_remote_target_nodenum = (int)node_num; + } else { + pr_err("ramster: bad num to node node_num=%d?\n", + (int)node_num); + return -EINVAL; + } + return count; +} + +static struct kobj_attribute ramster_remote_target_nodenum_attr = { + .attr = { .name = "remote_target_nodenum", .mode = 0644 }, + .show = ramster_remote_target_nodenum_show, + .store = ramster_remote_target_nodenum_store, +}; + + +static struct attribute *ramster_attrs[] = { + &ramster_interface_revision_attr.attr, + &ramster_pers_remotify_enable_attr.attr, + &ramster_eph_remotify_enable_attr.attr, + &ramster_remote_pers_pages_attr.attr, + &ramster_eph_pages_remoted_attr.attr, + &ramster_eph_pages_remote_failed_attr.attr, + &ramster_pers_pages_remoted_attr.attr, + &ramster_pers_pages_remote_failed_attr.attr, + &ramster_pers_pages_remote_nomem_attr.attr, + &ramster_remote_pages_flushed_attr.attr, + &ramster_remote_page_flushes_failed_attr.attr, + &ramster_remote_objects_flushed_attr.attr, + &ramster_remote_object_flushes_failed_attr.attr, + &ramster_remote_eph_pages_succ_get_attr.attr, + &ramster_remote_eph_pages_unsucc_get_attr.attr, + &ramster_remote_pers_pages_succ_get_attr.attr, + &ramster_remote_pers_pages_unsucc_get_attr.attr, + &ramster_foreign_eph_pampd_count_attr.attr, + &ramster_foreign_eph_pampd_count_max_attr.attr, + &ramster_foreign_pers_pampd_count_attr.attr, + &ramster_foreign_pers_pampd_count_max_attr.attr, + &ramster_curr_flnode_count_attr.attr, + &ramster_curr_flnode_count_max_attr.attr, + &ramster_manual_node_up_attr.attr, + &ramster_remote_target_nodenum_attr.attr, + NULL, +}; + +static struct attribute_group ramster_attr_group = { + .attrs = ramster_attrs, + .name = "ramster", +}; + #endif /* CONFIG_SYSFS */ /* * When zcache is disabled ("frozen"), pools can be created and destroyed, @@ -1510,8 +2618,9 @@ static struct shrinker zcache_shrinker = { * zcache shims between cleancache/frontswap ops and tmem */ -static int zcache_put_page(int cli_id, int pool_id, struct tmem_oid *oidp, - uint32_t index, struct page *page) +int zcache_put(int cli_id, int pool_id, struct tmem_oid *oidp, + uint32_t index, char *data, size_t size, + bool raw, int ephemeral) { struct tmem_pool *pool; int ret = -1; @@ -1522,8 +2631,7 @@ static int zcache_put_page(int cli_id, int pool_id, struct tmem_oid *oidp, goto out; if (!zcache_freeze && zcache_do_preload(pool) == 0) { /* preload does preempt_disable on success */ - ret = tmem_put(pool, oidp, index, (char *)(page), - PAGE_SIZE, 0, is_ephemeral(pool)); + ret = tmem_put(pool, oidp, index, data, size, raw, ephemeral); if (ret < 0) { if (is_ephemeral(pool)) zcache_failed_eph_puts++; @@ -1543,27 +2651,38 @@ out: return ret; } -static int zcache_get_page(int cli_id, int pool_id, struct tmem_oid *oidp, - uint32_t index, struct page *page) +int zcache_get(int cli_id, int pool_id, struct tmem_oid *oidp, + uint32_t index, char *data, size_t *sizep, + bool raw, int get_and_free) { struct tmem_pool *pool; int ret = -1; - unsigned long flags; - size_t size = PAGE_SIZE; + bool eph; - local_irq_save(flags); + if (!raw) { + BUG_ON(irqs_disabled()); + BUG_ON(in_softirq()); + } pool = zcache_get_pool_by_id(cli_id, pool_id); + eph = is_ephemeral(pool); if (likely(pool != NULL)) { if (atomic_read(&pool->obj_count) > 0) - ret = tmem_get(pool, oidp, index, (char *)(page), - &size, 0, is_ephemeral(pool)); + ret = tmem_get(pool, oidp, index, data, sizep, + raw, get_and_free); zcache_put_pool(pool); } - local_irq_restore(flags); + WARN_ONCE((!eph && (ret != 0)), "zcache_get fails on persistent pool, " + "bad things are very likely to happen soon\n"); +#ifdef RAMSTER_TESTING + if (ret != 0 && ret != -1 && !(ret == -EINVAL && is_ephemeral(pool))) + pr_err("TESTING zcache_get tmem_get returns ret=%d\n", ret); +#endif + if (ret == -EAGAIN) + BUG(); /* FIXME... don't need this anymore??? let's ensure */ return ret; } -static int zcache_flush_page(int cli_id, int pool_id, +int zcache_flush(int cli_id, int pool_id, struct tmem_oid *oidp, uint32_t index) { struct tmem_pool *pool; @@ -1573,6 +2692,7 @@ static int zcache_flush_page(int cli_id, int pool_id, local_irq_save(flags); zcache_flush_total++; pool = zcache_get_pool_by_id(cli_id, pool_id); + ramster_do_preload_flnode_only(pool); if (likely(pool != NULL)) { if (atomic_read(&pool->obj_count) > 0) ret = tmem_flush_page(pool, oidp, index); @@ -1584,8 +2704,7 @@ static int zcache_flush_page(int cli_id, int pool_id, return ret; } -static int zcache_flush_object(int cli_id, int pool_id, - struct tmem_oid *oidp) +int zcache_flush_object(int cli_id, int pool_id, struct tmem_oid *oidp) { struct tmem_pool *pool; int ret = -1; @@ -1594,6 +2713,7 @@ static int zcache_flush_object(int cli_id, int pool_id, local_irq_save(flags); zcache_flobj_total++; pool = zcache_get_pool_by_id(cli_id, pool_id); + ramster_do_preload_flnode_only(pool); if (likely(pool != NULL)) { if (atomic_read(&pool->obj_count) > 0) ret = tmem_flush_object(pool, oidp); @@ -1605,7 +2725,7 @@ static int zcache_flush_object(int cli_id, int pool_id, return ret; } -static int zcache_destroy_pool(int cli_id, int pool_id) +int zcache_client_destroy_pool(int cli_id, int pool_id) { struct tmem_pool *pool = NULL; struct zcache_client *cli = NULL; @@ -1632,13 +2752,17 @@ static int zcache_destroy_pool(int cli_id, int pool_id) ret = tmem_destroy_pool(pool); local_bh_enable(); kfree(pool); - pr_info("zcache: destroyed pool id=%d, cli_id=%d\n", - pool_id, cli_id); + pr_info("ramster: destroyed pool id=%d cli_id=%d\n", pool_id, cli_id); out: return ret; } -static int zcache_new_pool(uint16_t cli_id, uint32_t flags) +static int zcache_destroy_pool(int pool_id) +{ + return zcache_client_destroy_pool(LOCAL_CLIENT, pool_id); +} + +int zcache_new_pool(uint16_t cli_id, uint32_t flags) { int poolid = -1; struct tmem_pool *pool; @@ -1653,7 +2777,7 @@ static int zcache_new_pool(uint16_t cli_id, uint32_t flags) atomic_inc(&cli->refcount); pool = kmalloc(sizeof(struct tmem_pool), GFP_ATOMIC); if (pool == NULL) { - pr_info("zcache: pool creation failed: out of memory\n"); + pr_info("ramster: pool creation failed: out of memory\n"); goto out; } @@ -1661,7 +2785,7 @@ static int zcache_new_pool(uint16_t cli_id, uint32_t flags) if (cli->tmem_pools[poolid] == NULL) break; if (poolid >= MAX_POOLS_PER_CLIENT) { - pr_info("zcache: pool creation failed: max exceeded\n"); + pr_info("ramster: pool creation failed: max exceeded\n"); kfree(pool); poolid = -1; goto out; @@ -1671,15 +2795,78 @@ static int zcache_new_pool(uint16_t cli_id, uint32_t flags) pool->pool_id = poolid; tmem_new_pool(pool, flags); cli->tmem_pools[poolid] = pool; - pr_info("zcache: created %s tmem pool, id=%d, client=%d\n", - flags & TMEM_POOL_PERSIST ? "persistent" : "ephemeral", - poolid, cli_id); + if (cli_id == LOCAL_CLIENT) + pr_info("ramster: created %s tmem pool, id=%d, local client\n", + flags & TMEM_POOL_PERSIST ? "persistent" : "ephemeral", + poolid); + else + pr_info("ramster: created %s tmem pool, id=%d, client=%d\n", + flags & TMEM_POOL_PERSIST ? "persistent" : "ephemeral", + poolid, cli_id); out: if (cli != NULL) atomic_dec(&cli->refcount); return poolid; } +static int zcache_local_new_pool(uint32_t flags) +{ + return zcache_new_pool(LOCAL_CLIENT, flags); +} + +int zcache_autocreate_pool(int cli_id, int pool_id, bool ephemeral) +{ + struct tmem_pool *pool; + struct zcache_client *cli = NULL; + uint32_t flags = ephemeral ? 0 : TMEM_POOL_PERSIST; + int ret = -1; + + if (cli_id == LOCAL_CLIENT) + goto out; + if (pool_id >= MAX_POOLS_PER_CLIENT) + goto out; + else if ((unsigned int)cli_id < MAX_CLIENTS) + cli = &zcache_clients[cli_id]; + if ((ephemeral && !use_cleancache) || (!ephemeral && !use_frontswap)) + BUG(); /* FIXME, handle more gracefully later */ + if (!cli->allocated) { + if (zcache_new_client(cli_id)) + BUG(); /* FIXME, handle more gracefully later */ + cli = &zcache_clients[cli_id]; + } + atomic_inc(&cli->refcount); + pool = cli->tmem_pools[pool_id]; + if (pool != NULL) { + if (pool->persistent && ephemeral) { + pr_err("zcache_autocreate_pool: type mismatch\n"); + goto out; + } + ret = 0; + goto out; + } + pool = kmalloc(sizeof(struct tmem_pool), GFP_KERNEL); + if (pool == NULL) { + pr_info("ramster: pool creation failed: out of memory\n"); + goto out; + } + atomic_set(&pool->refcount, 0); + pool->client = cli; + pool->pool_id = pool_id; + tmem_new_pool(pool, flags); + cli->tmem_pools[pool_id] = pool; + pr_info("ramster: AUTOcreated %s tmem poolid=%d, for remote client=%d\n", + flags & TMEM_POOL_PERSIST ? "persistent" : "ephemeral", + pool_id, cli_id); + ret = 0; +out: + if (cli == NULL) + BUG(); /* FIXME, handle more gracefully later */ + /* pr_err("zcache_autocreate_pool: failed\n"); */ + if (cli != NULL) + atomic_dec(&cli->refcount); + return ret; +} + /********** * Two kernel functionalities currently can be layered on top of tmem. * These are "cleancache" which is used as a second-chance cache for clean @@ -1696,8 +2883,18 @@ static void zcache_cleancache_put_page(int pool_id, u32 ind = (u32) index; struct tmem_oid oid = *(struct tmem_oid *)&key; - if (likely(ind == index)) - (void)zcache_put_page(LOCAL_CLIENT, pool_id, &oid, index, page); +#ifdef __PG_WAS_ACTIVE + if (!PageWasActive(page)) { + zcache_nonactive_puts++; + return; + } +#endif + if (likely(ind == index)) { + char *kva = page_address(page); + + (void)zcache_put(LOCAL_CLIENT, pool_id, &oid, index, + kva, PAGE_SIZE, 0, 1); + } } static int zcache_cleancache_get_page(int pool_id, @@ -1708,8 +2905,19 @@ static int zcache_cleancache_get_page(int pool_id, struct tmem_oid oid = *(struct tmem_oid *)&key; int ret = -1; - if (likely(ind == index)) - ret = zcache_get_page(LOCAL_CLIENT, pool_id, &oid, index, page); + preempt_disable(); + if (likely(ind == index)) { + char *kva = page_address(page); + size_t size = PAGE_SIZE; + + ret = zcache_get(LOCAL_CLIENT, pool_id, &oid, index, + kva, &size, 0, 0); +#ifdef __PG_WAS_ACTIVE + if (ret == 0) + SetPageWasActive(page); +#endif + } + preempt_enable(); return ret; } @@ -1721,7 +2929,7 @@ static void zcache_cleancache_flush_page(int pool_id, struct tmem_oid oid = *(struct tmem_oid *)&key; if (likely(ind == index)) - (void)zcache_flush_page(LOCAL_CLIENT, pool_id, &oid, ind); + (void)zcache_flush(LOCAL_CLIENT, pool_id, &oid, ind); } static void zcache_cleancache_flush_inode(int pool_id, @@ -1735,7 +2943,7 @@ static void zcache_cleancache_flush_inode(int pool_id, static void zcache_cleancache_flush_fs(int pool_id) { if (pool_id >= 0) - (void)zcache_destroy_pool(LOCAL_CLIENT, pool_id); + (void)zcache_destroy_pool(pool_id); } static int zcache_cleancache_init_fs(size_t pagesize) @@ -1743,7 +2951,7 @@ static int zcache_cleancache_init_fs(size_t pagesize) BUG_ON(sizeof(struct cleancache_filekey) != sizeof(struct tmem_oid)); BUG_ON(pagesize != PAGE_SIZE); - return zcache_new_pool(LOCAL_CLIENT, 0); + return zcache_local_new_pool(0); } static int zcache_cleancache_init_shared_fs(char *uuid, size_t pagesize) @@ -1752,7 +2960,7 @@ static int zcache_cleancache_init_shared_fs(char *uuid, size_t pagesize) BUG_ON(sizeof(struct cleancache_filekey) != sizeof(struct tmem_oid)); BUG_ON(pagesize != PAGE_SIZE); - return zcache_new_pool(LOCAL_CLIENT, 0); + return zcache_local_new_pool(0); } static struct cleancache_ops zcache_cleancache_ops = { @@ -1781,10 +2989,8 @@ static int zcache_frontswap_poolid = -1; /* * Swizzling increases objects per swaptype, increasing tmem concurrency * for heavy swaploads. Later, larger nr_cpus -> larger SWIZ_BITS - * Setting SWIZ_BITS to 27 basically reconstructs the swap entry from - * frontswap_get_page() */ -#define SWIZ_BITS 27 +#define SWIZ_BITS 8 #define SWIZ_MASK ((1 << SWIZ_BITS) - 1) #define _oswiz(_type, _ind) ((_type << SWIZ_BITS) | (_ind & SWIZ_MASK)) #define iswiz(_ind) (_ind >> SWIZ_BITS) @@ -1804,12 +3010,14 @@ static int zcache_frontswap_put_page(unsigned type, pgoff_t offset, struct tmem_oid oid = oswiz(type, ind); int ret = -1; unsigned long flags; + char *kva; BUG_ON(!PageLocked(page)); if (likely(ind64 == ind)) { local_irq_save(flags); - ret = zcache_put_page(LOCAL_CLIENT, zcache_frontswap_poolid, - &oid, iswiz(ind), page); + kva = page_address(page); + ret = zcache_put(LOCAL_CLIENT, zcache_frontswap_poolid, + &oid, iswiz(ind), kva, PAGE_SIZE, 0, 0); local_irq_restore(flags); } return ret; @@ -1825,10 +3033,16 @@ static int zcache_frontswap_get_page(unsigned type, pgoff_t offset, struct tmem_oid oid = oswiz(type, ind); int ret = -1; + preempt_disable(); /* FIXME, remove this? */ BUG_ON(!PageLocked(page)); - if (likely(ind64 == ind)) - ret = zcache_get_page(LOCAL_CLIENT, zcache_frontswap_poolid, - &oid, iswiz(ind), page); + if (likely(ind64 == ind)) { + char *kva = page_address(page); + size_t size = PAGE_SIZE; + + ret = zcache_get(LOCAL_CLIENT, zcache_frontswap_poolid, + &oid, iswiz(ind), kva, &size, 0, -1); + } + preempt_enable(); /* FIXME, remove this? */ return ret; } @@ -1840,7 +3054,7 @@ static void zcache_frontswap_flush_page(unsigned type, pgoff_t offset) struct tmem_oid oid = oswiz(type, ind); if (likely(ind64 == ind)) - (void)zcache_flush_page(LOCAL_CLIENT, zcache_frontswap_poolid, + (void)zcache_flush(LOCAL_CLIENT, zcache_frontswap_poolid, &oid, iswiz(ind)); } @@ -1862,7 +3076,7 @@ static void zcache_frontswap_init(unsigned ignored) /* a single tmem poolid is used for all frontswap "types" (swapfiles) */ if (zcache_frontswap_poolid < 0) zcache_frontswap_poolid = - zcache_new_pool(LOCAL_CLIENT, TMEM_POOL_PERSIST); + zcache_local_new_pool(TMEM_POOL_PERSIST); } static struct frontswap_ops zcache_frontswap_ops = { @@ -1882,20 +3096,126 @@ struct frontswap_ops zcache_frontswap_register_ops(void) } #endif +/* + * frontswap selfshrinking + */ + +#ifdef CONFIG_FRONTSWAP +/* In HZ, controls frequency of worker invocation. */ +static unsigned int selfshrink_interval __read_mostly = 5; + +static void selfshrink_process(struct work_struct *work); +static DECLARE_DELAYED_WORK(selfshrink_worker, selfshrink_process); + +/* Enable/disable with sysfs. */ +static bool frontswap_selfshrinking __read_mostly; + +/* Enable/disable with kernel boot option. */ +static bool use_frontswap_selfshrink __initdata = true; + +/* + * The default values for the following parameters were deemed reasonable + * by experimentation, may be workload-dependent, and can all be + * adjusted via sysfs. + */ + +/* Control rate for frontswap shrinking. Higher hysteresis is slower. */ +static unsigned int frontswap_hysteresis __read_mostly = 20; + +/* + * Number of selfshrink worker invocations to wait before observing that + * frontswap selfshrinking should commence. Note that selfshrinking does + * not use a separate worker thread. + */ +static unsigned int frontswap_inertia __read_mostly = 3; + +/* Countdown to next invocation of frontswap_shrink() */ +static unsigned long frontswap_inertia_counter; + +/* + * Invoked by the selfshrink worker thread, uses current number of pages + * in frontswap (frontswap_curr_pages()), previous status, and control + * values (hysteresis and inertia) to determine if frontswap should be + * shrunk and what the new frontswap size should be. Note that + * frontswap_shrink is essentially a partial swapoff that immediately + * transfers pages from the "swap device" (frontswap) back into kernel + * RAM; despite the name, frontswap "shrinking" is very different from + * the "shrinker" interface used by the kernel MM subsystem to reclaim + * memory. + */ +static void frontswap_selfshrink(void) +{ + static unsigned long cur_frontswap_pages; + static unsigned long last_frontswap_pages; + static unsigned long tgt_frontswap_pages; + + last_frontswap_pages = cur_frontswap_pages; + cur_frontswap_pages = frontswap_curr_pages(); + if (!cur_frontswap_pages || + (cur_frontswap_pages > last_frontswap_pages)) { + frontswap_inertia_counter = frontswap_inertia; + return; + } + if (frontswap_inertia_counter && --frontswap_inertia_counter) + return; + if (cur_frontswap_pages <= frontswap_hysteresis) + tgt_frontswap_pages = 0; + else + tgt_frontswap_pages = cur_frontswap_pages - + (cur_frontswap_pages / frontswap_hysteresis); + frontswap_shrink(tgt_frontswap_pages); +} + +static int __init ramster_nofrontswap_selfshrink_setup(char *s) +{ + use_frontswap_selfshrink = false; + return 1; +} + +__setup("noselfshrink", ramster_nofrontswap_selfshrink_setup); + +static void selfshrink_process(struct work_struct *work) +{ + if (frontswap_selfshrinking && frontswap_enabled) { + frontswap_selfshrink(); + schedule_delayed_work(&selfshrink_worker, + selfshrink_interval * HZ); + } +} + +static int ramster_enabled; + +static int __init ramster_selfshrink_init(void) +{ + frontswap_selfshrinking = ramster_enabled && use_frontswap_selfshrink; + if (frontswap_selfshrinking) + pr_info("ramster: Initializing frontswap " + "selfshrinking driver.\n"); + else + return -ENODEV; + + schedule_delayed_work(&selfshrink_worker, selfshrink_interval * HZ); + + return 0; +} + +subsys_initcall(ramster_selfshrink_init); +#endif + /* * zcache initialization - * NOTE FOR NOW zcache MUST BE PROVIDED AS A KERNEL BOOT PARAMETER OR + * NOTE FOR NOW ramster MUST BE PROVIDED AS A KERNEL BOOT PARAMETER OR * NOTHING HAPPENS! */ -static int zcache_enabled; +static int ramster_enabled; -static int __init enable_zcache(char *s) +static int __init enable_ramster(char *s) { - zcache_enabled = 1; + ramster_enabled = 1; return 1; } -__setup("zcache", enable_zcache); +__setup("ramster", enable_ramster); /* allow independent dynamic disabling of cleancache and frontswap */ @@ -1903,16 +3223,22 @@ static int use_cleancache = 1; static int __init no_cleancache(char *s) { + pr_info("INIT no_cleancache called\n"); use_cleancache = 0; return 1; } -__setup("nocleancache", no_cleancache); +/* + * FIXME: need to guarantee this gets checked before zcache_init is called + * What is the correct way to achieve this? + */ +early_param("nocleancache", no_cleancache); static int use_frontswap = 1; static int __init no_frontswap(char *s) { + pr_info("INIT no_frontswap called\n"); use_frontswap = 0; return 1; } @@ -1925,20 +3251,22 @@ static int __init zcache_init(void) #ifdef CONFIG_SYSFS ret = sysfs_create_group(mm_kobj, &zcache_attr_group); + ret = sysfs_create_group(mm_kobj, &ramster_attr_group); if (ret) { - pr_err("zcache: can't create sysfs\n"); + pr_err("ramster: can't create sysfs\n"); goto out; } #endif /* CONFIG_SYSFS */ #if defined(CONFIG_CLEANCACHE) || defined(CONFIG_FRONTSWAP) - if (zcache_enabled) { + if (ramster_enabled) { unsigned int cpu; + (void)r2net_register_handlers(); tmem_register_hostops(&zcache_hostops); tmem_register_pamops(&zcache_pamops); ret = register_cpu_notifier(&zcache_cpu_notifier_block); if (ret) { - pr_err("zcache: can't register cpu notifier\n"); + pr_err("ramster: can't register cpu notifier\n"); goto out; } for_each_online_cpu(cpu) { @@ -1951,35 +3279,39 @@ static int __init zcache_init(void) sizeof(struct tmem_objnode), 0, 0, NULL); zcache_obj_cache = kmem_cache_create("zcache_obj", sizeof(struct tmem_obj), 0, 0, NULL); - ret = zcache_new_client(LOCAL_CLIENT); - if (ret) { - pr_err("zcache: can't create client\n"); - goto out; - } + ramster_flnode_cache = kmem_cache_create("ramster_flnode", + sizeof(struct flushlist_node), 0, 0, NULL); #endif #ifdef CONFIG_CLEANCACHE - if (zcache_enabled && use_cleancache) { + pr_info("INIT ramster_enabled=%d use_cleancache=%d\n", + ramster_enabled, use_cleancache); + if (ramster_enabled && use_cleancache) { struct cleancache_ops old_ops; zbud_init(); register_shrinker(&zcache_shrinker); old_ops = zcache_cleancache_register_ops(); - pr_info("zcache: cleancache enabled using kernel " + pr_info("ramster: cleancache enabled using kernel " "transcendent memory and compression buddies\n"); if (old_ops.init_fs != NULL) - pr_warning("zcache: cleancache_ops overridden"); + pr_warning("ramster: cleancache_ops overridden"); } #endif #ifdef CONFIG_FRONTSWAP - if (zcache_enabled && use_frontswap) { + pr_info("INIT ramster_enabled=%d use_frontswap=%d\n", + ramster_enabled, use_frontswap); + if (ramster_enabled && use_frontswap) { struct frontswap_ops old_ops; + zcache_new_client(LOCAL_CLIENT); old_ops = zcache_frontswap_register_ops(); - pr_info("zcache: frontswap enabled using kernel " + pr_info("ramster: frontswap enabled using kernel " "transcendent memory and xvmalloc\n"); if (old_ops.init != NULL) - pr_warning("zcache: frontswap_ops overridden"); + pr_warning("ramster: frontswap_ops overridden"); } + if (ramster_enabled && (use_frontswap || use_cleancache)) + ramster_remotify_init(); #endif out: return ret; -- 2.20.1