[PATCH 37/39] xfs: avoid cil push lock if possible
From: Dave Chinner <david@fromorbit.com>
Date: 2021-05-19 12:13:34
Subsystem:
filesystems (vfs and infrastructure), the rest, xfs filesystem · Maintainers:
Alexander Viro, Christian Brauner, Linus Torvalds, Carlos Maiolino
From: Dave Chinner <redacted>
Because now it hurts when the CIL fills up.
- 37.20% __xfs_trans_commit
- 35.84% xfs_log_commit_cil
- 19.34% _raw_spin_lock
- do_raw_spin_lock
19.01% __pv_queued_spin_lock_slowpath
- 4.20% xfs_log_ticket_ungrant
0.90% xfs_log_space_wake
Signed-off-by: Dave Chinner <redacted>
---
fs/xfs/xfs_log_cil.c | 14 +++++++++++---
1 file changed, 11 insertions(+), 3 deletions(-)
diff --git a/fs/xfs/xfs_log_cil.c b/fs/xfs/xfs_log_cil.c
index cfd3128399f6..672cbaa4606c 100644
--- a/fs/xfs/xfs_log_cil.c
+++ b/fs/xfs/xfs_log_cil.c@@ -1125,10 +1125,18 @@ xlog_cil_push_background( ASSERT(!test_bit(XLOG_CIL_EMPTY, &cil->xc_flags)); /* - * Don't do a background push if we haven't used up all the - * space available yet. + * We are done if: + * - we haven't used up all the space available yet; or + * - we've already queued up a push; and + * - we're not over the hard limit; and + * - nothing has been over the hard limit. + * + * If so, we don't need to take the push lock as there's nothing to do. */ - if (space_used < XLOG_CIL_SPACE_LIMIT(log)) { + if (space_used < XLOG_CIL_SPACE_LIMIT(log) || + (cil->xc_push_seq == cil->xc_current_sequence && + space_used < XLOG_CIL_BLOCKING_SPACE_LIMIT(log) && + !waitqueue_active(&cil->xc_push_wait))) { up_read(&cil->xc_ctx_lock); return; }
--
2.31.1