The patch titled
Subject: fs/buffer.c: add checking buffer head stat before clear
has been added to the -mm tree. Its filename is
fs-bufferc-add-checking-buffer-head-stat-before-clear.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/fs-bufferc-add-checking-buffer-head-stat-before-clear.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/fs-bufferc-add-checking-buffer-head-stat-before-clear.patch
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Yang Guo <guoyang2@xxxxxxxxxx>
Subject: fs/buffer.c: add checking buffer head stat before clear
clear_buffer_new() is used to clear buffer new stat. When PAGE_SIZE is
64K, most buffer heads in the list are not needed to clear.
clear_buffer_new() has an enpensive atomic modification operation, Let's
add checking buffer head before clear it as __block_write_begin_int does
which is good for performance.
Link: https://lkml.kernel.org/r/1612332890-57918-1-git-send-email-zhangshaokun@xxxxxxxxxxxxx
Signed-off-by: Yang Guo <guoyang2@xxxxxxxxxx>
Signed-off-by: Shaokun Zhang <zhangshaokun@xxxxxxxxxxxxx>
Cc: Alexander Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: Nick Piggin <npiggin@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/buffer.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
--- a/fs/buffer.c~fs-bufferc-add-checking-buffer-head-stat-before-clear
+++ a/fs/buffer.c
@@ -2083,7 +2083,8 @@ static int __block_commit_write(struct i
set_buffer_uptodate(bh);
mark_buffer_dirty(bh);
}
- clear_buffer_new(bh);
+ if (buffer_new(bh))
+ clear_buffer_new(bh);
block_start = block_end;
bh = bh->b_this_page;
_
Patches currently in -mm which might be from guoyang2@xxxxxxxxxx are
fs-bufferc-add-checking-buffer-head-stat-before-clear.patch
