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 <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Alex Elder <aelder@sgi.com>
This commit is contained in:
Dave Chinner 2010-11-30 17:27:57 +11:00 committed by Dave Chinner
parent 1a427ab0c1
commit ff57ab2199
2 changed files with 27 additions and 66 deletions

View File

@ -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)
int
xfs_buftarg_shrink(
struct shrinker *shrink,
int nr_to_scan,
gfp_t mask)
{
spin_lock(&xfs_buftarg_lock);
list_add(&btp->bt_list, &xfs_buftarg_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);
}
STATIC void
xfs_unregister_buftarg(
xfs_buftarg_t *btp)
{
spin_lock(&xfs_buftarg_lock);
list_del(&btp->bt_list);
spin_unlock(&xfs_buftarg_lock);
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);

View File

@ -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;
/*