On 07/24/2013 08:08 PM, Cyrill Gorcunov 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. > > To resolve this we introduce _PTE_SWP_SOFT_DIRTY bit which is > saved in pte entry for the page being swapped out. When such page > is to be read back from a swap cache we check for bit presence > and if it's there we clear it and restore the former _PAGE_SOFT_DIRTY > bit back. > > One of the problem was to find a place in pte entry where we can > save the _PTE_SWP_SOFT_DIRTY bit while page is in swap. The > _PAGE_PSE was chosen for that, it doesn't intersect with swap > entry format stored in pte. > > Reported-by: Andy Lutomirski <[email protected]> > Signed-off-by: Pavel Emelyanov <[email protected]> > Signed-off-by: Cyrill Gorcunov <[email protected]> > Cc: Andrew Morton <[email protected]> > Cc: Matt Mackall <[email protected]> > Cc: Xiao Guangrong <[email protected]> > Cc: Marcelo Tosatti <[email protected]> > Cc: KOSAKI Motohiro <[email protected]> > Cc: Stephen Rothwell <[email protected]>
Acked-by: Pavel Emelyanov <[email protected]> -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
