Messages in this thread Patch in this message | | | From | Chao Yu <> | Subject | [PATCH 3/3] f2fs: update comments for explicit memory barrier | Date | Sat, 20 Feb 2021 17:38:43 +0800 |
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Add more detailed comments for explicit memory barrier used by f2fs, in order to enhance code readability.
Signed-off-by: Chao Yu <yuchao0@huawei.com> --- fs/f2fs/checkpoint.c | 6 +++++- fs/f2fs/segment.c | 6 +++++- 2 files changed, 10 insertions(+), 2 deletions(-)
diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c index 174a0819ad96..c75866cd72fa 100644 --- a/fs/f2fs/checkpoint.c +++ b/fs/f2fs/checkpoint.c @@ -1818,7 +1818,11 @@ int f2fs_issue_checkpoint(struct f2fs_sb_info *sbi) llist_add(&req.llnode, &cprc->issue_list); atomic_inc(&cprc->queued_ckpt); - /* update issue_list before we wake up issue_checkpoint thread */ + /* + * update issue_list before we wake up issue_checkpoint thread, + * this smp_mb() pairs with another barrier in ___wait_event(), + * see more details in comments of waitqueue_active(). + */ smp_mb(); if (waitqueue_active(&cprc->ckpt_wait_queue)) diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c index 2190910c68b0..2d5a82c4ca15 100644 --- a/fs/f2fs/segment.c +++ b/fs/f2fs/segment.c @@ -663,7 +663,11 @@ int f2fs_issue_flush(struct f2fs_sb_info *sbi, nid_t ino) llist_add(&cmd.llnode, &fcc->issue_list); - /* update issue_list before we wake up issue_flush thread */ + /* + * update issue_list before we wake up issue_flush thread, this + * smp_mb() pairs with another barrier in ___wait_event(), see + * more details in comments of waitqueue_active(). + */ smp_mb(); if (waitqueue_active(&fcc->flush_wait_queue)) -- 2.29.2
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