Unverified Commit d4501697 authored by openeuler-ci-bot's avatar openeuler-ci-bot Committed by Gitee
Browse files

!14035 Backport fs optimizing patch from mainline 

Merge Pull Request from: @ci-robot 
 
PR sync from: Zheng Zengkai <zhengzengkai@huawei.com>
https://mailweb.openeuler.org/hyperkitty/list/kernel@openeuler.org/message/TTFXSKJMXLKG72HQT7MC76ITXZHROJMB/ 
64 bits in open_fds are mapped to a common bit in full_fds_bits. It is very
likely that a bit in full_fds_bits has been cleared before in
__clear_open_fds()'s operation. Check the clear bit in full_fds_bits before
clearing to avoid unnecessary write and cache bouncing. See commit fc90888d
("vfs: conditionally clear close-on-exec flag") for a similar optimization.
take stock kernel with patch 1 as baseline, it improves pts/blogbench-1.1.0
read for 13%, and write for 5% on Intel ICX 160 cores configuration with
v6.10-rc7.

Yu Ma (1):
  fs/file.c: conditionally clear full_fds


-- 
2.20.1
 
https://gitee.com/openeuler/kernel/issues/IB8ROX 
 
Link:https://gitee.com/openeuler/kernel/pulls/14035

 

Reviewed-by: default avatarzhangyi (F) <yi.zhang@huawei.com>
Signed-off-by: default avatarZhang Peng <zhangpeng362@huawei.com>
parents f1eaa672 3f60bf6a

fs/file.c

+3 −1
Original line number Diff line number Diff line
@@ -265,7 +265,9 @@ static inline void __set_open_fd(unsigned int fd, struct fdtable *fdt) 
static inline void __clear_open_fd(unsigned int fd, struct fdtable *fdt)

{

	__clear_bit(fd, fdt->open_fds);

	__clear_bit(fd / BITS_PER_LONG, fdt->full_fds_bits);

	fd /= BITS_PER_LONG;

	if (test_bit(fd, fdt->full_fds_bits))

		__clear_bit(fd, fdt->full_fds_bits);

}



/*