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mm/page_io: count submission time as thrashing delay for delayacct

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Once upon a time, we only support accounting thrashing of page cache. 
Then Joonsoo introduced workingset detection for anonymous pages and we
gained the ability to account thrashing of them[1].

Likes PSI, we count submission time as thrashing delay because when the
device is congested, or the submitting cgroup IO-throttled, submission can
be a significant part of overall IO time.

Without this patch, swap thrashing through frontswap or some block
device supporting rw_page operation isn't measured correctly.

This patch is based on "delayacct: support re-entrance detection of
thrashing accounting".

[1] commit aae466b005 ("mm/swap: implement workingset detection for anonymous LRU")

Link: https://lkml.kernel.org/r/20220815072835.74876-1-yang.yang29@zte.com.cn
Signed-off-by: Yang Yang <yang.yang29@zte.com.cn>
Signed-off-by: CGEL ZTE <cgel.zte@gmail.com>
Reviewed-by: Ran Xiaokai <ran.xiaokai@zte.com.cn>
Reviewed-by: wangyong <wang.yong12@zte.com.cn>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Yang Yang 2022-08-15 07:28:37 +00:00 committed by Andrew Morton
parent aa1cf99b87
commit 3a9bb7b187
1 changed files with 10 additions and 5 deletions
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15
mm/page_io.c
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@ -452,18 +452,21 @@ int swap_readpage(struct page *page, bool synchronous,
struct swap_info_struct *sis = page_swap_info(page); struct swap_info_struct *sis = page_swap_info(page);
bool workingset = PageWorkingset(page); bool workingset = PageWorkingset(page);
unsigned long pflags; unsigned long pflags;
bool in_thrashing;
VM_BUG_ON_PAGE(!PageSwapCache(page) && !synchronous, page); VM_BUG_ON_PAGE(!PageSwapCache(page) && !synchronous, page);
VM_BUG_ON_PAGE(!PageLocked(page), page); VM_BUG_ON_PAGE(!PageLocked(page), page);
VM_BUG_ON_PAGE(PageUptodate(page), page); VM_BUG_ON_PAGE(PageUptodate(page), page);
/* /*
* Count submission time as memory stall. When the device is congested, * Count submission time as memory stall and delay. When the device
* or the submitting cgroup IO-throttled, submission can be a * is congested, or the submitting cgroup IO-throttled, submission
* significant part of overall IO time. * can be a significant part of overall IO time.
*/ */
if (workingset) if (workingset) {
delayacct_thrashing_start(&in_thrashing);
psi_memstall_enter(&pflags); psi_memstall_enter(&pflags);
}
delayacct_swapin_start(); delayacct_swapin_start();
if (frontswap_load(page) == 0) { if (frontswap_load(page) == 0) {
@ -512,8 +515,10 @@ int swap_readpage(struct page *page, bool synchronous,
bio_put(bio); bio_put(bio);
out: out:
if (workingset) if (workingset) {
delayacct_thrashing_end(&in_thrashing);
psi_memstall_leave(&pflags); psi_memstall_leave(&pflags);
}
delayacct_swapin_end(); delayacct_swapin_end();
return ret; return ret;
} }