[PATCH 1/8] xfs: use per-filesystem I/O completion workqueues

Christoph Hellwig
2012-02-29T09:55:11Z

[-- Attachment #1: xfs-split-workqueues --]
[-- Type: text/plain, Size: 7529 bytes --]

The new concurrency managed workqueues are cheap enough that we can create
per-filesystem instead of global workqueues. This allows us to remove the
trylock or defer scheme on the ilock, which is not helpful once we have
outstanding log reservations until finishing a size update.

Also allow the default concurrency on this workqueues so that I/O completions
blocking on the ilock for one inode do not block process for another inode.

Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

---
fs/xfs/xfs_aops.c | 39 ++++++++++-----------------------------
fs/xfs/xfs_aops.h | 2 --
fs/xfs/xfs_buf.c | 17 -----------------
fs/xfs/xfs_mount.h | 3 +++
fs/xfs/xfs_super.c | 39 ++++++++++++++++++++++++++++++++++++++-
5 files changed, 51 insertions(+), 49 deletions(-)

Index: xfs/fs/xfs/xfs_aops.c
===================================================================
--- xfs.orig/fs/xfs/xfs_aops.c 2012-02-13 15:59:57.997159607 -0800
+++ xfs/fs/xfs/xfs_aops.c 2012-02-19 13:21:45.653291774 -0800
@@ -126,21 +126,15 @@ static inline bool xfs_ioend_is_append(s

/*
* Update on-disk file size now that data has been written to disk.
- *
- * This function does not block as blocking on the inode lock in IO completion
- * can lead to IO completion order dependency deadlocks.. If it can't get the
- * inode ilock it will return EAGAIN. Callers must handle this.
*/
-STATIC int
+STATIC void
xfs_setfilesize(
- xfs_ioend_t *ioend)
+ struct xfs_ioend *ioend)
{
- xfs_inode_t *ip = XFS_I(ioend->io_inode);
+ struct xfs_inode *ip = XFS_I(ioend->io_inode);
xfs_fsize_t isize;

- if (!xfs_ilock_nowait(ip, XFS_ILOCK_EXCL))
- return EAGAIN;
-
+ xfs_ilock(ip, XFS_ILOCK_EXCL);
isize = xfs_ioend_new_eof(ioend);
if (isize) {
trace_xfs_setfilesize(ip, ioend->io_offset, ioend->io_size);
@@ -149,7 +143,6 @@ xfs_setfilesize(
}

xfs_iunlock(ip, XFS_ILOCK_EXCL);
- return 0;
}

/*
@@ -163,10 +156,12 @@ xfs_finish_ioend(
struct xfs_ioend *ioend)
{
if (atomic_dec_and_test(&ioend->io_remaining)) {
+ struct xfs_mount *mp = XFS_I(ioend->io_inode)->i_mount;
+
if (ioend->io_type == IO_UNWRITTEN)
- queue_work(xfsconvertd_workqueue, &ioend->io_work);
+ queue_work(mp->m_unwritten_workqueue, &ioend->io_work);
else if (xfs_ioend_is_append(ioend))
- queue_work(xfsdatad_workqueue, &ioend->io_work);
+ queue_work(mp->m_data_workqueue, &ioend->io_work);
else
xfs_destroy_ioend(ioend);
}
@@ -207,23 +202,9 @@ xfs_end_io(
* We might have to update the on-disk file size after extending
* writes.
*/
- error = xfs_setfilesize(ioend);
- ASSERT(!error || error == EAGAIN);
-
+ xfs_setfilesize(ioend);
done:
- /*
- * If we didn't complete processing of the ioend, requeue it to the
- * tail of the workqueue for another attempt later. Otherwise destroy
- * it.
- */
- if (error == EAGAIN) {
- atomic_inc(&ioend->io_remaining);
- xfs_finish_ioend(ioend);
- /* ensure we don't spin on blocked ioends */
- delay(1);
- } else {
- xfs_destroy_ioend(ioend);
- }
+ xfs_destroy_ioend(ioend);
}

/*
Index: xfs/fs/xfs/xfs_aops.h
===================================================================
--- xfs.orig/fs/xfs/xfs_aops.h 2012-02-13 13:48:02.390346163 -0800
+++ xfs/fs/xfs/xfs_aops.h 2012-02-19 13:21:45.653291774 -0800
@@ -18,8 +18,6 @@
#ifndef __XFS_AOPS_H__
#define __XFS_AOPS_H__

-extern struct workqueue_struct *xfsdatad_workqueue;
-extern struct workqueue_struct *xfsconvertd_workqueue;
extern mempool_t *xfs_ioend_pool;

/*
Index: xfs/fs/xfs/xfs_buf.c
===================================================================
--- xfs.orig/fs/xfs/xfs_buf.c 2012-02-13 13:48:02.393679497 -0800
+++ xfs/fs/xfs/xfs_buf.c 2012-02-19 13:21:45.653291774 -0800
@@ -45,8 +45,6 @@ static kmem_zone_t *xfs_buf_zone;
STATIC int xfsbufd(void *);

static struct workqueue_struct *xfslogd_workqueue;
-struct workqueue_struct *xfsdatad_workqueue;
-struct workqueue_struct *xfsconvertd_workqueue;

#ifdef XFS_BUF_LOCK_TRACKING
# define XB_SET_OWNER(bp) ((bp)->b_last_holder = current->pid)
@@ -1793,21 +1791,8 @@ xfs_buf_init(void)
if (!xfslogd_workqueue)
goto out_free_buf_zone;

- xfsdatad_workqueue = alloc_workqueue("xfsdatad", WQ_MEM_RECLAIM, 1);
- if (!xfsdatad_workqueue)
- goto out_destroy_xfslogd_workqueue;
-
- xfsconvertd_workqueue = alloc_workqueue("xfsconvertd",
- WQ_MEM_RECLAIM, 1);
- if (!xfsconvertd_workqueue)
- goto out_destroy_xfsdatad_workqueue;
-
return 0;

- out_destroy_xfsdatad_workqueue:
- destroy_workqueue(xfsdatad_workqueue);
- out_destroy_xfslogd_workqueue:
- destroy_workqueue(xfslogd_workqueue);
out_free_buf_zone:
kmem_zone_destroy(xfs_buf_zone);
out:
@@ -1817,8 +1802,6 @@ xfs_buf_init(void)
void
xfs_buf_terminate(void)
{
- destroy_workqueue(xfsconvertd_workqueue);
- destroy_workqueue(xfsdatad_workqueue);
destroy_workqueue(xfslogd_workqueue);
kmem_zone_destroy(xfs_buf_zone);
}
Index: xfs/fs/xfs/xfs_super.c
===================================================================
--- xfs.orig/fs/xfs/xfs_super.c 2012-02-19 12:58:45.823295509 -0800
+++ xfs/fs/xfs/xfs_super.c 2012-02-19 13:23:48.836624774 -0800
@@ -759,6 +759,36 @@ xfs_setup_devices(
return 0;
}

+STATIC int
+xfs_init_mount_workqueues(
+ struct xfs_mount *mp)
+{
+ mp->m_data_workqueue = alloc_workqueue("xfs-data/%s",
+ WQ_MEM_RECLAIM, 0, mp->m_fsname);
+ if (!mp->m_data_workqueue)
+ goto out;
+
+ mp->m_unwritten_workqueue = alloc_workqueue("xfs-conv/%s",
+ WQ_MEM_RECLAIM, 0, mp->m_fsname);
+ if (!mp->m_unwritten_workqueue)
+ goto out_destroy_data_iodone_queue;
+
+ return 0;
+
+out_destroy_data_iodone_queue:
+ destroy_workqueue(mp->m_data_workqueue);
+out:
+ return -ENOMEM;
+}
+
+STATIC void
+xfs_destroy_mount_workqueues(
+ struct xfs_mount *mp)
+{
+ destroy_workqueue(mp->m_data_workqueue);
+ destroy_workqueue(mp->m_unwritten_workqueue);
+}
+
/* Catch misguided souls that try to use this interface on XFS */
STATIC struct inode *
xfs_fs_alloc_inode(
@@ -982,6 +1012,7 @@ xfs_fs_put_super(
xfs_unmountfs(mp);
xfs_freesb(mp);
xfs_icsb_destroy_counters(mp);
+ xfs_destroy_mount_workqueues(mp);
xfs_close_devices(mp);
xfs_free_fsname(mp);
kfree(mp);
@@ -1308,10 +1339,14 @@ xfs_fs_fill_super(
if (error)
goto out_free_fsname;

- error = xfs_icsb_init_counters(mp);
+ error = xfs_init_mount_workqueues(mp);
if (error)
goto out_close_devices;

+ error = xfs_icsb_init_counters(mp);
+ if (error)
+ goto out_destroy_workqueues;
+
error = xfs_readsb(mp, flags);
if (error)
goto out_destroy_counters;
@@ -1374,6 +1409,8 @@ xfs_fs_fill_super(
xfs_freesb(mp);
out_destroy_counters:
xfs_icsb_destroy_counters(mp);
+out_destroy_workqueues:
+ xfs_destroy_mount_workqueues(mp);
out_close_devices:
xfs_close_devices(mp);
out_free_fsname:
Index: xfs/fs/xfs/xfs_mount.h
===================================================================
--- xfs.orig/fs/xfs/xfs_mount.h 2012-02-13 13:48:02.410346163 -0800
+++ xfs/fs/xfs/xfs_mount.h 2012-02-19 13:21:45.656625108 -0800
@@ -211,6 +211,9 @@ typedef struct xfs_mount {
struct shrinker m_inode_shrink; /* inode reclaim shrinker */
int64_t m_low_space[XFS_LOWSP_MAX];
/* low free space thresholds */
+
+ struct workqueue_struct *m_data_workqueue;
+ struct workqueue_struct *m_unwritten_workqueue;
} xfs_mount_t;

/*