Messages in this thread | | | Date | Wed, 24 Jul 2013 20:37:34 +0400 | From | Cyrill Gorcunov <> | Subject | Re: [PATCH] mm: Save soft-dirty bits on swapped pages |
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On Wed, Jul 24, 2013 at 09:23:14AM -0700, Andy Lutomirski wrote: > On Wed, Jul 24, 2013 at 9:08 AM, Cyrill Gorcunov <gorcunov@gmail.com> wrote: > > Andy Lutomirski reported that in case if a page with _PAGE_SOFT_DIRTY > > bit set get swapped out, the bit is getting lost and no longer > > available when pte read back. > > Potentially silly question (due to my completely lack of understanding > of how swapping works in Linux): what about file-backed pages? > (Arguably these would be best supported by filesystems instead of by > the core vm, in which case it might make sense to drop soft-dirty > support for these pages entirely.)
Hi Andy, if I understand you correctly "file-backed pages" are carried in pte with _PAGE_FILE bit set and the swap soft-dirty bit won't be used on them but _PAGE_SOFT_DIRTY will be set on write if only I've not missed something obvious (Pavel?).
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