| Date | Tue, 21 Jul 2015 16:35:00 -0700 | From | Andrew Morton <> | Subject | Re: [PATCH -mm v9 7/8] proc: export idle flag via kpageflags |
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On Sun, 19 Jul 2015 15:31:16 +0300 Vladimir Davydov <vdavydov@parallels.com> wrote:
> As noted by Minchan, a benefit of reading idle flag from > /proc/kpageflags is that one can easily filter dirty and/or unevictable > pages while estimating the size of unused memory. > > Note that idle flag read from /proc/kpageflags may be stale in case the > page was accessed via a PTE, because it would be too costly to iterate > over all page mappings on each /proc/kpageflags read to provide an > up-to-date value. To make sure the flag is up-to-date one has to read > /proc/kpageidle first.
Is there any value in teaching the regular old page scanner to update these flags? If it's doing an rmap scan anyway...
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