From ff57ab21995a8636cfc72efeebb09cc6034d756f Mon Sep 17 00:00:00 2001 From: Dave Chinner Date: Tue, 30 Nov 2010 17:27:57 +1100 Subject: [PATCH] xfs: convert xfsbud shrinker to a per-buftarg shrinker. Before we introduce per-buftarg LRU lists, split the shrinker implementation into per-buftarg shrinker callbacks. At the moment we wake all the xfsbufds to run the delayed write queues to free the dirty buffers and make their pages available for reclaim. However, with an LRU, we want to be able to free clean, unused buffers as well, so we need to separate the xfsbufd from the shrinker callbacks. Signed-off-by: Dave Chinner Reviewed-by: Christoph Hellwig Reviewed-by: Alex Elder --- fs/xfs/linux-2.6/xfs_buf.c | 89 ++++++++++---------------------------- fs/xfs/linux-2.6/xfs_buf.h | 4 +- 2 files changed, 27 insertions(+), 66 deletions(-) diff --git a/fs/xfs/linux-2.6/xfs_buf.c b/fs/xfs/linux-2.6/xfs_buf.c index 4c5deb6e9e3..0a00d7a2fc2 100644 --- a/fs/xfs/linux-2.6/xfs_buf.c +++ b/fs/xfs/linux-2.6/xfs_buf.c @@ -44,12 +44,7 @@ static kmem_zone_t *xfs_buf_zone; STATIC int xfsbufd(void *); -STATIC int xfsbufd_wakeup(struct shrinker *, int, gfp_t); STATIC void xfs_buf_delwri_queue(xfs_buf_t *, int); -static struct shrinker xfs_buf_shake = { - .shrink = xfsbufd_wakeup, - .seeks = DEFAULT_SEEKS, -}; static struct workqueue_struct *xfslogd_workqueue; struct workqueue_struct *xfsdatad_workqueue; @@ -337,7 +332,6 @@ _xfs_buf_lookup_pages( __func__, gfp_mask); XFS_STATS_INC(xb_page_retries); - xfsbufd_wakeup(NULL, 0, gfp_mask); congestion_wait(BLK_RW_ASYNC, HZ/50); goto retry; } @@ -1461,28 +1455,23 @@ xfs_wait_buftarg( } } -/* - * buftarg list for delwrite queue processing - */ -static LIST_HEAD(xfs_buftarg_list); -static DEFINE_SPINLOCK(xfs_buftarg_lock); - -STATIC void -xfs_register_buftarg( - xfs_buftarg_t *btp) -{ - spin_lock(&xfs_buftarg_lock); - list_add(&btp->bt_list, &xfs_buftarg_list); - spin_unlock(&xfs_buftarg_lock); -} - -STATIC void -xfs_unregister_buftarg( - xfs_buftarg_t *btp) +int +xfs_buftarg_shrink( + struct shrinker *shrink, + int nr_to_scan, + gfp_t mask) { - spin_lock(&xfs_buftarg_lock); - list_del(&btp->bt_list); - spin_unlock(&xfs_buftarg_lock); + struct xfs_buftarg *btp = container_of(shrink, + struct xfs_buftarg, bt_shrinker); + if (nr_to_scan) { + if (test_bit(XBT_FORCE_SLEEP, &btp->bt_flags)) + return -1; + if (list_empty(&btp->bt_delwrite_queue)) + return -1; + set_bit(XBT_FORCE_FLUSH, &btp->bt_flags); + wake_up_process(btp->bt_task); + } + return list_empty(&btp->bt_delwrite_queue) ? -1 : 1; } void @@ -1490,17 +1479,14 @@ xfs_free_buftarg( struct xfs_mount *mp, struct xfs_buftarg *btp) { + unregister_shrinker(&btp->bt_shrinker); + xfs_flush_buftarg(btp, 1); if (mp->m_flags & XFS_MOUNT_BARRIER) xfs_blkdev_issue_flush(btp); iput(btp->bt_mapping->host); - /* Unregister the buftarg first so that we don't get a - * wakeup finding a non-existent task - */ - xfs_unregister_buftarg(btp); kthread_stop(btp->bt_task); - kmem_free(btp); } @@ -1597,20 +1583,13 @@ xfs_alloc_delwrite_queue( xfs_buftarg_t *btp, const char *fsname) { - int error = 0; - - INIT_LIST_HEAD(&btp->bt_list); INIT_LIST_HEAD(&btp->bt_delwrite_queue); spin_lock_init(&btp->bt_delwrite_lock); btp->bt_flags = 0; btp->bt_task = kthread_run(xfsbufd, btp, "xfsbufd/%s", fsname); - if (IS_ERR(btp->bt_task)) { - error = PTR_ERR(btp->bt_task); - goto out_error; - } - xfs_register_buftarg(btp); -out_error: - return error; + if (IS_ERR(btp->bt_task)) + return PTR_ERR(btp->bt_task); + return 0; } xfs_buftarg_t * @@ -1633,6 +1612,9 @@ xfs_alloc_buftarg( goto error; if (xfs_alloc_delwrite_queue(btp, fsname)) goto error; + btp->bt_shrinker.shrink = xfs_buftarg_shrink; + btp->bt_shrinker.seeks = DEFAULT_SEEKS; + register_shrinker(&btp->bt_shrinker); return btp; error: @@ -1737,27 +1719,6 @@ xfs_buf_runall_queues( flush_workqueue(queue); } -STATIC int -xfsbufd_wakeup( - struct shrinker *shrink, - int priority, - gfp_t mask) -{ - xfs_buftarg_t *btp; - - spin_lock(&xfs_buftarg_lock); - list_for_each_entry(btp, &xfs_buftarg_list, bt_list) { - if (test_bit(XBT_FORCE_SLEEP, &btp->bt_flags)) - continue; - if (list_empty(&btp->bt_delwrite_queue)) - continue; - set_bit(XBT_FORCE_FLUSH, &btp->bt_flags); - wake_up_process(btp->bt_task); - } - spin_unlock(&xfs_buftarg_lock); - return 0; -} - /* * Move as many buffers as specified to the supplied list * idicating if we skipped any buffers to prevent deadlocks. @@ -1952,7 +1913,6 @@ xfs_buf_init(void) if (!xfsconvertd_workqueue) goto out_destroy_xfsdatad_workqueue; - register_shrinker(&xfs_buf_shake); return 0; out_destroy_xfsdatad_workqueue: @@ -1968,7 +1928,6 @@ xfs_buf_init(void) void xfs_buf_terminate(void) { - unregister_shrinker(&xfs_buf_shake); destroy_workqueue(xfsconvertd_workqueue); destroy_workqueue(xfsdatad_workqueue); destroy_workqueue(xfslogd_workqueue); diff --git a/fs/xfs/linux-2.6/xfs_buf.h b/fs/xfs/linux-2.6/xfs_buf.h index 383a3f37cf9..9344103e77d 100644 --- a/fs/xfs/linux-2.6/xfs_buf.h +++ b/fs/xfs/linux-2.6/xfs_buf.h @@ -128,10 +128,12 @@ typedef struct xfs_buftarg { /* per device delwri queue */ struct task_struct *bt_task; - struct list_head bt_list; struct list_head bt_delwrite_queue; spinlock_t bt_delwrite_lock; unsigned long bt_flags; + + /* LRU control structures */ + struct shrinker bt_shrinker; } xfs_buftarg_t; /* -- 2.20.1