From d52f847a841bfeba0ea87a7842732d388a1ca2e8 Mon Sep 17 00:00:00 2001 From: Sage Weil Date: Thu, 1 Apr 2010 15:23:14 -0700 Subject: [PATCH] ceph: rewrite msgpool using mempool_t Since we don't need to maintain large pools of messages, we can just use the standard mempool_t. We maintain a msgpool 'wrapper' because we need the mempool_t* in the alloc function, and mempool gives us only pool_data. Signed-off-by: Sage Weil --- fs/ceph/msgpool.c | 172 ++++++++-------------------------------------- fs/ceph/msgpool.h | 8 +-- 2 files changed, 29 insertions(+), 151 deletions(-) diff --git a/fs/ceph/msgpool.c b/fs/ceph/msgpool.c index 030297f62fb7..ca032223e87b 100644 --- a/fs/ceph/msgpool.c +++ b/fs/ceph/msgpool.c @@ -7,106 +7,43 @@ #include "msgpool.h" -/* - * We use msg pools to preallocate memory for messages we expect to - * receive over the wire, to avoid getting ourselves into OOM - * conditions at unexpected times. We take use a few different - * strategies: - * - * - for request/response type interactions, we preallocate the - * memory needed for the response when we generate the request. - * - * - for messages we can receive at any time from the MDS, we preallocate - * a pool of messages we can re-use. - * - * - for writeback, we preallocate some number of messages to use for - * requests and their replies, so that we always make forward - * progress. - * - * The msgpool behaves like a mempool_t, but keeps preallocated - * ceph_msgs strung together on a list_head instead of using a pointer - * vector. This avoids vector reallocation when we adjust the number - * of preallocated items (which happens frequently). - */ +static void *alloc_fn(gfp_t gfp_mask, void *arg) +{ + struct ceph_msgpool *pool = arg; + struct ceph_msg *m; + m = ceph_msg_new(0, pool->front_len, 0, 0, NULL); + if (IS_ERR(m)) + return NULL; + return m; +} -/* - * Allocate or release as necessary to meet our target pool size. - */ -static int __fill_msgpool(struct ceph_msgpool *pool) +static void free_fn(void *element, void *arg) { - struct ceph_msg *msg; - - while (pool->num < pool->min) { - dout("fill_msgpool %p %d/%d allocating\n", pool, pool->num, - pool->min); - spin_unlock(&pool->lock); - msg = ceph_msg_new(0, pool->front_len, 0, 0, NULL); - spin_lock(&pool->lock); - if (IS_ERR(msg)) - return PTR_ERR(msg); - msg->pool = pool; - list_add(&msg->list_head, &pool->msgs); - pool->num++; - } - while (pool->num > pool->min) { - msg = list_first_entry(&pool->msgs, struct ceph_msg, list_head); - dout("fill_msgpool %p %d/%d releasing %p\n", pool, pool->num, - pool->min, msg); - list_del_init(&msg->list_head); - pool->num--; - ceph_msg_kfree(msg); - } - return 0; + ceph_msg_put(element); } int ceph_msgpool_init(struct ceph_msgpool *pool, - int front_len, int min, bool blocking) + int front_len, int size, bool blocking) { - int ret; - - dout("msgpool_init %p front_len %d min %d\n", pool, front_len, min); - spin_lock_init(&pool->lock); pool->front_len = front_len; - INIT_LIST_HEAD(&pool->msgs); - pool->num = 0; - pool->min = min; - pool->blocking = blocking; - init_waitqueue_head(&pool->wait); - - spin_lock(&pool->lock); - ret = __fill_msgpool(pool); - spin_unlock(&pool->lock); - return ret; + pool->pool = mempool_create(size, alloc_fn, free_fn, pool); + if (!pool->pool) + return -ENOMEM; + return 0; } void ceph_msgpool_destroy(struct ceph_msgpool *pool) { - dout("msgpool_destroy %p\n", pool); - spin_lock(&pool->lock); - pool->min = 0; - __fill_msgpool(pool); - spin_unlock(&pool->lock); -} - -int ceph_msgpool_resv(struct ceph_msgpool *pool, int delta) -{ - int ret; - - spin_lock(&pool->lock); - dout("msgpool_resv %p delta %d\n", pool, delta); - pool->min += delta; - ret = __fill_msgpool(pool); - spin_unlock(&pool->lock); - return ret; + mempool_destroy(pool->pool); } -struct ceph_msg *ceph_msgpool_get(struct ceph_msgpool *pool, int front_len) +struct ceph_msg *ceph_msgpool_get(struct ceph_msgpool *pool, + int front_len) { - wait_queue_t wait; - struct ceph_msg *msg; + if (front_len > pool->front_len) { + struct ceph_msg *msg; - if (front_len && front_len > pool->front_len) { pr_err("msgpool_get pool %p need front %d, pool size is %d\n", pool, front_len, pool->front_len); WARN_ON(1); @@ -115,72 +52,17 @@ struct ceph_msg *ceph_msgpool_get(struct ceph_msgpool *pool, int front_len) msg = ceph_msg_new(0, front_len, 0, 0, NULL); if (!IS_ERR(msg)) return msg; + return NULL; } - if (!front_len) - front_len = pool->front_len; - - if (pool->blocking) { - /* mempool_t behavior; first try to alloc */ - msg = ceph_msg_new(0, front_len, 0, 0, NULL); - if (!IS_ERR(msg)) - return msg; - } - - while (1) { - spin_lock(&pool->lock); - if (likely(pool->num)) { - msg = list_entry(pool->msgs.next, struct ceph_msg, - list_head); - list_del_init(&msg->list_head); - pool->num--; - dout("msgpool_get %p got %p, now %d/%d\n", pool, msg, - pool->num, pool->min); - spin_unlock(&pool->lock); - return msg; - } - pr_err("msgpool_get %p now %d/%d, %s\n", pool, pool->num, - pool->min, pool->blocking ? "waiting" : "may fail"); - spin_unlock(&pool->lock); - - if (!pool->blocking) { - WARN_ON(1); - - /* maybe we can allocate it now? */ - msg = ceph_msg_new(0, front_len, 0, 0, NULL); - if (!IS_ERR(msg)) - return msg; - - pr_err("msgpool_get %p empty + alloc failed\n", pool); - return ERR_PTR(-ENOMEM); - } - - init_wait(&wait); - prepare_to_wait(&pool->wait, &wait, TASK_UNINTERRUPTIBLE); - schedule(); - finish_wait(&pool->wait, &wait); - } + return mempool_alloc(pool->pool, GFP_NOFS); } void ceph_msgpool_put(struct ceph_msgpool *pool, struct ceph_msg *msg) { - spin_lock(&pool->lock); - if (pool->num < pool->min) { - /* reset msg front_len; user may have changed it */ - msg->front.iov_len = pool->front_len; - msg->hdr.front_len = cpu_to_le32(pool->front_len); + /* reset msg front_len; user may have changed it */ + msg->front.iov_len = pool->front_len; + msg->hdr.front_len = cpu_to_le32(pool->front_len); - kref_init(&msg->kref); /* retake a single ref */ - list_add(&msg->list_head, &pool->msgs); - pool->num++; - dout("msgpool_put %p reclaim %p, now %d/%d\n", pool, msg, - pool->num, pool->min); - spin_unlock(&pool->lock); - wake_up(&pool->wait); - } else { - dout("msgpool_put %p drop %p, at %d/%d\n", pool, msg, - pool->num, pool->min); - spin_unlock(&pool->lock); - ceph_msg_kfree(msg); - } + kref_init(&msg->kref); /* retake single ref */ } diff --git a/fs/ceph/msgpool.h b/fs/ceph/msgpool.h index bc834bfcd720..62a61c7fca08 100644 --- a/fs/ceph/msgpool.h +++ b/fs/ceph/msgpool.h @@ -1,6 +1,7 @@ #ifndef _FS_CEPH_MSGPOOL #define _FS_CEPH_MSGPOOL +#include #include "messenger.h" /* @@ -8,18 +9,13 @@ * avoid unexpected OOM conditions. */ struct ceph_msgpool { - spinlock_t lock; + mempool_t *pool; int front_len; /* preallocated payload size */ - struct list_head msgs; /* msgs in the pool; each has 1 ref */ - int num, min; /* cur, min # msgs in the pool */ - bool blocking; - wait_queue_head_t wait; }; extern int ceph_msgpool_init(struct ceph_msgpool *pool, int front_len, int size, bool blocking); extern void ceph_msgpool_destroy(struct ceph_msgpool *pool); -extern int ceph_msgpool_resv(struct ceph_msgpool *, int delta); extern struct ceph_msg *ceph_msgpool_get(struct ceph_msgpool *, int front_len); extern void ceph_msgpool_put(struct ceph_msgpool *, struct ceph_msg *); -- 2.20.1