Commit b9306a79 authored Aug 06, 2020 by Yang Shi Committed by Linus Torvalds Aug 07, 2020

mm: filemap: clear idle flag for writes



Since commit bbddabe2 ("mm: filemap: only do access activations on
reads"), mark_page_accessed() is called for reads only.  But the idle flag
is cleared by mark_page_accessed() so the idle flag won't get cleared if
the page is write accessed only.

Basically idle page tracking is used to estimate workingset size of
workload, noticeable size of workingset might be missed if the idle flag
is not maintained correctly.

It seems good enough to just clear idle flag for write operations.

Fixes: bbddabe2 ("mm: filemap: only do access activations on reads")
Reported-by: Gang Deng <gavin.dg@linux.alibaba.com>
Signed-off-by: Yang Shi <yang.shi@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Rik van Riel <riel@surriel.com>
Link: http://lkml.kernel.org/r/1593020612-13051-1-git-send-email-yang.shi@linux.alibaba.com


Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 6dc5ea16

mm/filemap.c

+6 −0

Original line number	Diff line number	Diff line
		@@ -41,6 +41,7 @@
		#include <linux/delayacct.h>
		#include <linux/psi.h>
		#include <linux/ramfs.h>
		#include <linux/page_idle.h>
		#include "internal.h"

		#define CREATE_TRACE_POINTS
		@@ -1689,6 +1690,11 @@ repeat:

		if (fgp_flags & FGP_ACCESSED)
		mark_page_accessed(page);
		else if (fgp_flags & FGP_WRITE) {
		/* Clear idle flag for buffer write */
		if (page_is_idle(page))
		clear_page_idle(page);
		}

		no_page:
		if (!page && (fgp_flags & FGP_CREAT)) {

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