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; _
