On Tue, Jul 21, 2015 at 04:35:00PM -0700, Andrew Morton wrote: > On Sun, 19 Jul 2015 15:31:16 +0300 Vladimir Davydov <vdavydov@xxxxxxxxxxxxx> 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... I don't understand what you mean by "regular old page scanner". Could you please elaborate? Thanks, Vladimir -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
