2019-10-31 23:47:47

by Dave Chinner

[permalink] [raw]
Subject: [PATCH 26/28] xfs: use xfs_ail_push_all in xfs_reclaim_inodes

From: Dave Chinner <[email protected]>

If we are reclaiming all inodes, it is likely we need to flush the
entire AIL to do that. We have mechanisms to do that without needing
to push to a specific LSN.

Convert xfs_relaim_all_inodes() to use xfs_ail_push_all variant so
we can get rid of the hacky xfs_ail_push_sync() scaffolding we used
to support the intermediate stages of the non-blocking reclaim
changeset.

Signed-off-by: Dave Chinner <[email protected]>
---
fs/xfs/xfs_icache.c | 17 +++++++++++------
fs/xfs/xfs_trans_ail.c | 32 --------------------------------
fs/xfs/xfs_trans_priv.h | 2 --
3 files changed, 11 insertions(+), 40 deletions(-)

diff --git a/fs/xfs/xfs_icache.c b/fs/xfs/xfs_icache.c
index 71a729e29260..11bf4768d491 100644
--- a/fs/xfs/xfs_icache.c
+++ b/fs/xfs/xfs_icache.c
@@ -25,6 +25,7 @@
#include "xfs_log.h"

#include <linux/iversion.h>
+#include <linux/backing-dev.h> /* for congestion_wait() */

/*
* Allocate and initialise an xfs_inode.
@@ -1051,6 +1052,10 @@ xfs_dispose_inodes(
cond_resched();
}
}
+
+/*
+ * Reclaim all unused inodes in the filesystem.
+ */
void
xfs_reclaim_all_inodes(
struct xfs_mount *mp)
@@ -1059,6 +1064,9 @@ xfs_reclaim_all_inodes(
struct xfs_ireclaim_args ra;
long freed, to_free;

+ /* push the AIL to clean dirty reclaimable inodes */
+ xfs_ail_push_all(mp->m_ail);
+
xfs_ireclaim_args_init(&ra);

to_free = list_lru_count(&mp->m_inode_lru);
@@ -1066,13 +1074,10 @@ xfs_reclaim_all_inodes(
xfs_inode_reclaim_isolate, &ra, to_free);
xfs_dispose_inodes(&ra.freeable);

- if (freed == 0) {
+ if (freed == 0)
xfs_log_force(mp, XFS_LOG_SYNC);
- xfs_ail_push_all(mp->m_ail);
- } else if (ra.lowest_lsn != NULLCOMMITLSN) {
- xfs_ail_push_sync(mp->m_ail, ra.lowest_lsn);
- }
- cond_resched();
+ else if (ra.dirty_skipped)
+ congestion_wait(BLK_RW_ASYNC, HZ/10);
}
}

diff --git a/fs/xfs/xfs_trans_ail.c b/fs/xfs/xfs_trans_ail.c
index 3e1d0e1439e2..685a21cd24c0 100644
--- a/fs/xfs/xfs_trans_ail.c
+++ b/fs/xfs/xfs_trans_ail.c
@@ -662,36 +662,6 @@ xfs_ail_push_all(
xfs_ail_push(ailp, threshold_lsn);
}

-/*
- * Push the AIL to a specific lsn and wait for it to complete.
- */
-void
-xfs_ail_push_sync(
- struct xfs_ail *ailp,
- xfs_lsn_t threshold_lsn)
-{
- struct xfs_log_item *lip;
- DEFINE_WAIT(wait);
-
- spin_lock(&ailp->ail_lock);
- while ((lip = xfs_ail_min(ailp)) != NULL) {
- prepare_to_wait(&ailp->ail_push, &wait, TASK_UNINTERRUPTIBLE);
- if (XFS_FORCED_SHUTDOWN(ailp->ail_mount) ||
- XFS_LSN_CMP(threshold_lsn, lip->li_lsn) < 0)
- break;
- if (XFS_LSN_CMP(threshold_lsn, ailp->ail_target) > 0)
- ailp->ail_target = threshold_lsn;
- wake_up_process(ailp->ail_task);
- spin_unlock(&ailp->ail_lock);
- schedule();
- spin_lock(&ailp->ail_lock);
- }
- spin_unlock(&ailp->ail_lock);
-
- finish_wait(&ailp->ail_push, &wait);
-}
-
-
/*
* Push out all items in the AIL immediately and wait until the AIL is empty.
*/
@@ -732,7 +702,6 @@ xfs_ail_update_finish(
if (!XFS_FORCED_SHUTDOWN(mp))
xlog_assign_tail_lsn_locked(mp);

- wake_up_all(&ailp->ail_push);
if (list_empty(&ailp->ail_head))
wake_up_all(&ailp->ail_empty);
spin_unlock(&ailp->ail_lock);
@@ -889,7 +858,6 @@ xfs_trans_ail_init(
spin_lock_init(&ailp->ail_lock);
INIT_LIST_HEAD(&ailp->ail_buf_list);
init_waitqueue_head(&ailp->ail_empty);
- init_waitqueue_head(&ailp->ail_push);

ailp->ail_task = kthread_run(xfsaild, ailp, "xfsaild/%s",
ailp->ail_mount->m_fsname);
diff --git a/fs/xfs/xfs_trans_priv.h b/fs/xfs/xfs_trans_priv.h
index 1b6f4bbd47c0..35655eac01a6 100644
--- a/fs/xfs/xfs_trans_priv.h
+++ b/fs/xfs/xfs_trans_priv.h
@@ -61,7 +61,6 @@ struct xfs_ail {
int ail_log_flush;
struct list_head ail_buf_list;
wait_queue_head_t ail_empty;
- wait_queue_head_t ail_push;
};

/*
@@ -114,7 +113,6 @@ xfs_trans_ail_remove(
}

void xfs_ail_push(struct xfs_ail *, xfs_lsn_t);
-void xfs_ail_push_sync(struct xfs_ail *, xfs_lsn_t);
void xfs_ail_push_all(struct xfs_ail *);
void xfs_ail_push_all_sync(struct xfs_ail *);
struct xfs_log_item *xfs_ail_min(struct xfs_ail *ailp);
--
2.24.0.rc0


2019-11-06 17:25:07

by Brian Foster

[permalink] [raw]
Subject: Re: [PATCH 26/28] xfs: use xfs_ail_push_all in xfs_reclaim_inodes

On Fri, Nov 01, 2019 at 10:46:16AM +1100, Dave Chinner wrote:
> From: Dave Chinner <[email protected]>
>
> If we are reclaiming all inodes, it is likely we need to flush the
> entire AIL to do that. We have mechanisms to do that without needing
> to push to a specific LSN.
>
> Convert xfs_relaim_all_inodes() to use xfs_ail_push_all variant so
> we can get rid of the hacky xfs_ail_push_sync() scaffolding we used
> to support the intermediate stages of the non-blocking reclaim
> changeset.
>
> Signed-off-by: Dave Chinner <[email protected]>
> ---
> fs/xfs/xfs_icache.c | 17 +++++++++++------
> fs/xfs/xfs_trans_ail.c | 32 --------------------------------
> fs/xfs/xfs_trans_priv.h | 2 --
> 3 files changed, 11 insertions(+), 40 deletions(-)
>
> diff --git a/fs/xfs/xfs_icache.c b/fs/xfs/xfs_icache.c
> index 71a729e29260..11bf4768d491 100644
> --- a/fs/xfs/xfs_icache.c
> +++ b/fs/xfs/xfs_icache.c
...
> @@ -1066,13 +1074,10 @@ xfs_reclaim_all_inodes(
> xfs_inode_reclaim_isolate, &ra, to_free);
> xfs_dispose_inodes(&ra.freeable);
>
> - if (freed == 0) {
> + if (freed == 0)
> xfs_log_force(mp, XFS_LOG_SYNC);
> - xfs_ail_push_all(mp->m_ail);
> - } else if (ra.lowest_lsn != NULLCOMMITLSN) {
> - xfs_ail_push_sync(mp->m_ail, ra.lowest_lsn);
> - }
> - cond_resched();
> + else if (ra.dirty_skipped)
> + congestion_wait(BLK_RW_ASYNC, HZ/10);

Why not use xfs_ail_push_all_sync() in this function and skip the direct
stall? This is only used in the unmount and quiesce paths so the big
hammer approach seems reasonable. As it is, the former already calls
xfs_ail_push_all_sync() before xfs_reclaim_all_inodes() and the latter
calls xfs_log_force(mp, XFS_LOG_SYNC).

Brian

> }
> }
>
> diff --git a/fs/xfs/xfs_trans_ail.c b/fs/xfs/xfs_trans_ail.c
> index 3e1d0e1439e2..685a21cd24c0 100644
> --- a/fs/xfs/xfs_trans_ail.c
> +++ b/fs/xfs/xfs_trans_ail.c
> @@ -662,36 +662,6 @@ xfs_ail_push_all(
> xfs_ail_push(ailp, threshold_lsn);
> }
>
> -/*
> - * Push the AIL to a specific lsn and wait for it to complete.
> - */
> -void
> -xfs_ail_push_sync(
> - struct xfs_ail *ailp,
> - xfs_lsn_t threshold_lsn)
> -{
> - struct xfs_log_item *lip;
> - DEFINE_WAIT(wait);
> -
> - spin_lock(&ailp->ail_lock);
> - while ((lip = xfs_ail_min(ailp)) != NULL) {
> - prepare_to_wait(&ailp->ail_push, &wait, TASK_UNINTERRUPTIBLE);
> - if (XFS_FORCED_SHUTDOWN(ailp->ail_mount) ||
> - XFS_LSN_CMP(threshold_lsn, lip->li_lsn) < 0)
> - break;
> - if (XFS_LSN_CMP(threshold_lsn, ailp->ail_target) > 0)
> - ailp->ail_target = threshold_lsn;
> - wake_up_process(ailp->ail_task);
> - spin_unlock(&ailp->ail_lock);
> - schedule();
> - spin_lock(&ailp->ail_lock);
> - }
> - spin_unlock(&ailp->ail_lock);
> -
> - finish_wait(&ailp->ail_push, &wait);
> -}
> -
> -
> /*
> * Push out all items in the AIL immediately and wait until the AIL is empty.
> */
> @@ -732,7 +702,6 @@ xfs_ail_update_finish(
> if (!XFS_FORCED_SHUTDOWN(mp))
> xlog_assign_tail_lsn_locked(mp);
>
> - wake_up_all(&ailp->ail_push);
> if (list_empty(&ailp->ail_head))
> wake_up_all(&ailp->ail_empty);
> spin_unlock(&ailp->ail_lock);
> @@ -889,7 +858,6 @@ xfs_trans_ail_init(
> spin_lock_init(&ailp->ail_lock);
> INIT_LIST_HEAD(&ailp->ail_buf_list);
> init_waitqueue_head(&ailp->ail_empty);
> - init_waitqueue_head(&ailp->ail_push);
>
> ailp->ail_task = kthread_run(xfsaild, ailp, "xfsaild/%s",
> ailp->ail_mount->m_fsname);
> diff --git a/fs/xfs/xfs_trans_priv.h b/fs/xfs/xfs_trans_priv.h
> index 1b6f4bbd47c0..35655eac01a6 100644
> --- a/fs/xfs/xfs_trans_priv.h
> +++ b/fs/xfs/xfs_trans_priv.h
> @@ -61,7 +61,6 @@ struct xfs_ail {
> int ail_log_flush;
> struct list_head ail_buf_list;
> wait_queue_head_t ail_empty;
> - wait_queue_head_t ail_push;
> };
>
> /*
> @@ -114,7 +113,6 @@ xfs_trans_ail_remove(
> }
>
> void xfs_ail_push(struct xfs_ail *, xfs_lsn_t);
> -void xfs_ail_push_sync(struct xfs_ail *, xfs_lsn_t);
> void xfs_ail_push_all(struct xfs_ail *);
> void xfs_ail_push_all_sync(struct xfs_ail *);
> struct xfs_log_item *xfs_ail_min(struct xfs_ail *ailp);
> --
> 2.24.0.rc0
>

2019-11-14 21:55:39

by Dave Chinner

[permalink] [raw]
Subject: Re: [PATCH 26/28] xfs: use xfs_ail_push_all in xfs_reclaim_inodes

On Wed, Nov 06, 2019 at 12:22:15PM -0500, Brian Foster wrote:
> On Fri, Nov 01, 2019 at 10:46:16AM +1100, Dave Chinner wrote:
> > From: Dave Chinner <[email protected]>
> >
> > If we are reclaiming all inodes, it is likely we need to flush the
> > entire AIL to do that. We have mechanisms to do that without needing
> > to push to a specific LSN.
> >
> > Convert xfs_relaim_all_inodes() to use xfs_ail_push_all variant so
> > we can get rid of the hacky xfs_ail_push_sync() scaffolding we used
> > to support the intermediate stages of the non-blocking reclaim
> > changeset.
> >
> > Signed-off-by: Dave Chinner <[email protected]>
> > ---
> > fs/xfs/xfs_icache.c | 17 +++++++++++------
> > fs/xfs/xfs_trans_ail.c | 32 --------------------------------
> > fs/xfs/xfs_trans_priv.h | 2 --
> > 3 files changed, 11 insertions(+), 40 deletions(-)
> >
> > diff --git a/fs/xfs/xfs_icache.c b/fs/xfs/xfs_icache.c
> > index 71a729e29260..11bf4768d491 100644
> > --- a/fs/xfs/xfs_icache.c
> > +++ b/fs/xfs/xfs_icache.c
> ...
> > @@ -1066,13 +1074,10 @@ xfs_reclaim_all_inodes(
> > xfs_inode_reclaim_isolate, &ra, to_free);
> > xfs_dispose_inodes(&ra.freeable);
> >
> > - if (freed == 0) {
> > + if (freed == 0)
> > xfs_log_force(mp, XFS_LOG_SYNC);
> > - xfs_ail_push_all(mp->m_ail);
> > - } else if (ra.lowest_lsn != NULLCOMMITLSN) {
> > - xfs_ail_push_sync(mp->m_ail, ra.lowest_lsn);
> > - }
> > - cond_resched();
> > + else if (ra.dirty_skipped)
> > + congestion_wait(BLK_RW_ASYNC, HZ/10);
>
> Why not use xfs_ail_push_all_sync() in this function and skip the direct
> stall? This is only used in the unmount and quiesce paths so the big
> hammer approach seems reasonable.

Ok, that's a good simplification :)

-Dave.
--
Dave Chinner
[email protected]