From: Chao Yu <[email protected]> In f2fs_issue_flush, due to out-of-order execution of CPU, wake_up can be called before we insert issue_list, result in long latency of wait_for_completion. Fix this by adding smp_mb() to force the order of related codes.
Signed-off-by: Chao Yu <[email protected]> --- fs/f2fs/segment.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c index dd97d2f282a6..29de70b7a6c0 100644 --- a/fs/f2fs/segment.c +++ b/fs/f2fs/segment.c @@ -549,7 +549,10 @@ int f2fs_issue_flush(struct f2fs_sb_info *sbi) atomic_inc(&fcc->issing_flush); llist_add(&cmd.llnode, &fcc->issue_list); - if (!fcc->dispatch_list) + /* update issue_list before we wake up issue_flush thread */ + smp_mb(); + + if (waitqueue_active(&fcc->flush_wait_queue)) wake_up(&fcc->flush_wait_queue); if (fcc->f2fs_issue_flush) { -- 2.14.1.145.gb3622a4ee ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ Linux-f2fs-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
