linux/arch
Cyrill Gorcunov 179ef71cbc mm: save soft-dirty bits on swapped pages
Andy Lutomirski reported that 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 <luto@amacapital.net>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Acked-by: Pavel Emelyanov <xemul@parallels.com>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Reviewed-by: Minchan Kim <minchan@kernel.org>
Reviewed-by: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-08-13 17:57:47 -07:00
..
alpha alpha: Use handle_percpu_irq for the timer interrupt 2013-07-19 13:54:26 -07:00
arc ARC: SMP build breakage 2013-07-26 15:34:22 -07:00
arm fbdev fixes: 2013-08-09 11:52:34 -07:00
arm64 arm64: Change kernel stack size to 16K 2013-07-26 13:37:29 +01:00
avr32 avr32: boards/atngw100/mrmt.c: fix building error 2013-08-08 14:16:22 +02:00
blackfin Merge branch 'cpuinit_phase2' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux 2013-07-18 10:50:26 -07:00
c6x Merge branch 'akpm' (updates from Andrew Morton) 2013-07-03 17:12:13 -07:00
cris cris: delete __cpuinit usage from all cris files 2013-07-14 19:36:54 -04:00
frv frv: delete __cpuinit usage from all frv files 2013-07-14 19:36:55 -04:00
h8300 net: rename busy poll socket op and globals 2013-07-10 17:08:27 -07:00
hexagon hexagon: delete __cpuinit usage from all hexagon files 2013-07-14 19:36:55 -04:00
ia64 PCI: hotplug: Convert to be builtin only, not modular 2013-07-25 14:11:06 -06:00
m32r m32r: delete __cpuinit usage from all m32r files 2013-07-14 19:36:55 -04:00
m68k Merge branch 'akpm' (updates from Andrew Morton) 2013-07-03 17:12:13 -07:00
metag metag: delete __cpuinit usage from all metag files 2013-07-14 19:36:54 -04:00
microblaze Merge branch 'next' of git://git.monstr.eu/linux-2.6-microblaze 2013-07-10 10:16:07 -07:00
mips MIPS: BMIPS: fix hardware interrupt routing for boot CPU != 0 2013-08-05 13:35:18 +02:00
mn10300 net: rename busy poll socket op and globals 2013-07-10 17:08:27 -07:00
openrisc openrisc: delete __cpuinit usage from all openrisc files 2013-07-14 19:36:55 -04:00
parisc parisc: Fix interrupt routing for C8000 serial ports 2013-07-31 23:42:32 +02:00
powerpc powerpc/tm: Fix context switching TAR, PPR and DSCR SPRs 2013-08-09 18:07:12 +10:00
s390 Two fixes for s390 2013-08-11 12:11:33 -07:00
score score: delete __cpuinit usage from all score files 2013-07-14 19:36:56 -04:00
sh PCI: hotplug: Convert to be builtin only, not modular 2013-07-25 14:11:06 -06:00
sparc sparc: delete __cpuinit/__CPUINIT usage from all users 2013-07-14 19:36:52 -04:00
tile tile: delete __cpuinit usage from all tile files 2013-07-14 19:36:54 -04:00
um um: siginfo cleanup 2013-07-19 11:31:36 +02:00
unicore32 reboot: move arch/x86 reboot= handling to generic kernel 2013-07-09 10:33:29 -07:00
x86 mm: save soft-dirty bits on swapped pages 2013-08-13 17:57:47 -07:00
xtensa xtensa: delete __cpuinit usage from all xtensa files 2013-07-14 19:36:56 -04:00
.gitignore
Kconfig mm: soft-dirty bits for user memory changes tracking 2013-07-03 16:07:26 -07:00