Pavel Emelyanov 0f8975ec4d mm: soft-dirty bits for user memory changes tracking ... The soft-dirty is a bit on a PTE which helps to track which pages a task writes to. In order to do this tracking one should 1. Clear soft-dirty bits from PTEs ("echo 4 > /proc/PID/clear_refs) 2. Wait some time. 3. Read soft-dirty bits (55'th in /proc/PID/pagemap2 entries) To do this tracking, the writable bit is cleared from PTEs when the soft-dirty bit is. Thus, after this, when the task tries to modify a page at some virtual address the #PF occurs and the kernel sets the soft-dirty bit on the respective PTE. Note, that although all the task's address space is marked as r/o after the soft-dirty bits clear, the #PF-s that occur after that are processed fast. This is so, since the pages are still mapped to physical memory, and thus all the kernel does is finds this fact out and puts back writable, dirty and soft-dirty bits on the PTE. Another thing to note, is that when mremap moves PTEs they are marked with soft-dirty as well, since from the user perspective mremap modifies the virtual memory at mremap's new address. Signed-off-by: Pavel Emelyanov <xemul@parallels.com> Cc: Matt Mackall <mpm@selenic.com> Cc: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Cc: Glauber Costa <glommer@parallels.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		2013-07-03 16:07:26 -07:00
..
bitops	Merge branch 'modules-next' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux	2012-10-14 13:39:34 -07:00
4level-fixup.h
atomic-long.h
atomic.h	asm-generic: move cmpxchg*_local defs to cmpxchg.h	2013-03-13 06:11:05 +01:00
atomic64.h
audit_change_attr.h
audit_dir_write.h
audit_read.h
audit_signal.h
audit_write.h
barrier.h	Create asm-generic/barrier.h	2012-03-28 18:30:03 +01:00
bitops.h
bitsperlong.h	UAPI: (Scripted) Disintegrate include/asm-generic	2012-10-04 18:20:15 +01:00
bug.h	bug.h: Fix up CONFIG_BUG=n implicit function declarations.	2012-06-25 10:32:49 -07:00
bugs.h
cache.h
cacheflush.h	asm-generic/cacheflush.h: flush icache when copying to user pages	2011-05-25 08:39:37 -07:00
checksum.h	asm-generic headers: Allow yet more arch overrides in checksum.h	2013-02-11 20:00:33 +05:30
clkdev.h	asm-generic: Add default clkdev.h	2012-10-03 21:33:53 +02:00
cmpxchg-local.h	generic: Use raw local irq variant for generic cmpxchg	2013-02-19 08:43:37 +01:00
cmpxchg.h	asm-generic: move cmpxchg*_local defs to cmpxchg.h	2013-03-13 06:11:05 +01:00
cputime.h	cputime: Generic on-demand virtual cputime accounting	2013-01-27 19:23:27 +01:00
cputime_jiffies.h	cputime: Move default nsecs_to_cputime() to jiffies based cputime file	2013-01-27 19:23:25 +01:00
cputime_nsecs.h	cputime_nsecs: use math64.h for nsec resolution conversion helpers	2013-04-26 18:58:12 +02:00
current.h
delay.h	asm-generic: delay.h fix udelay and ndelay for 8 bit args	2011-07-22 18:45:33 +02:00
device.h
div64.h
dma-coherent.h	common: dma-mapping: add support for generic dma_mmap_* calls	2012-07-30 12:25:46 +02:00
dma-contiguous.h	mm: cma: fix condition check when setting global cma area	2012-07-06 12:02:04 +02:00
dma-mapping-broken.h	asm-generic/dma-mapping-broken.h: Provide dma_alloc_attrs()/dma_free_attrs()	2012-12-25 20:14:54 +01:00
dma-mapping-common.h	common: dma-mapping: introduce dma_get_sgtable() function	2012-07-30 12:25:46 +02:00
dma.h
emergency-restart.h
exec.h	Split arch_align_stack() out from asm-generic/system.h	2012-03-28 18:30:03 +01:00
fb.h
ftrace.h
futex.h
getorder.h	bitops: Add missing parentheses to new get_order macro	2012-02-24 10:39:27 -08:00
gpio.h	gpiolib: let gpio_chip reference its descriptors	2013-02-11 22:21:28 +00:00
hardirq.h
hugetlb.h	mm/hugetlb: add more arch-defined huge_pte functions	2013-04-29 15:54:33 -07:00
hw_irq.h
ide_iops.h
int-l64.h	UAPI: (Scripted) Disintegrate include/asm-generic	2012-10-04 18:20:15 +01:00
int-ll64.h	UAPI: (Scripted) Disintegrate include/asm-generic	2012-10-04 18:20:15 +01:00
io-64-nonatomic-hi-lo.h	asm-generic: architecture independent readq/writeq for 32bit environment	2012-02-21 16:47:28 -08:00
io-64-nonatomic-lo-hi.h	asm-generic: architecture independent readq/writeq for 32bit environment	2012-02-21 16:47:28 -08:00
io.h	kernel: Fix s390 absolute memory access for /dev/mem	2013-05-22 09:45:57 +02:00
ioctl.h	UAPI: (Scripted) Disintegrate include/asm-generic	2012-10-04 18:20:15 +01:00
iomap.h	[PARISC] fix compile break caused by iomap: make IOPORT/PCI mapping functions conditional	2012-02-27 09:43:30 -06:00
irq.h
irq_regs.h
irqflags.h
Kbuild.asm	UAPI: Set up uapi/asm/Kbuild.asm	2012-10-02 18:01:56 +01:00
kdebug.h
kmap_types.h	asm-generic: remove km_type definitions	2012-07-24 15:27:30 +08:00
kvm_para.h	KVM: add kvm_para_available to asm-generic/kvm_para.h	2013-06-05 13:21:29 +03:00
libata-portmap.h
linkage.h
local.h	atomic: use <linux/atomic.h>	2011-07-26 16:49:47 -07:00
local64.h	atomic: use <linux/atomic.h>	2011-07-26 16:49:47 -07:00
memory_model.h	mm: fix __page_to_pfn for a const struct page argument	2011-08-17 13:00:20 -07:00
mm_hooks.h
mmu.h	asm-generic/mmu.h: Add support for FDPIC	2012-12-09 23:14:14 +01:00
mmu_context.h
module.h	Make most arch asm/module.h files use asm-generic/module.h	2012-09-28 14:31:03 +09:30
mutex-dec.h	arch: Make __mutex_fastpath_lock_retval return whether fastpath succeeded or not	2013-06-26 12:10:55 +02:00
mutex-null.h	arch: Make __mutex_fastpath_lock_retval return whether fastpath succeeded or not	2013-06-26 12:10:55 +02:00
mutex-xchg.h	arch: Make __mutex_fastpath_lock_retval return whether fastpath succeeded or not	2013-06-26 12:10:55 +02:00
mutex.h
page.h	The following changes since commit 3ee72ca992	2012-01-10 17:39:40 -08:00
param.h	UAPI: (Scripted) Disintegrate include/asm-generic	2012-10-04 18:20:15 +01:00
parport.h	include: remove __dev* attributes.	2013-01-03 15:57:16 -08:00
pci-bridge.h	PCI: work around Stratus ftServer broken PCIe hierarchy	2012-04-30 15:21:02 -06:00
pci-dma-compat.h
pci.h	PCI: collapse pcibios_resource_to_bus	2012-02-23 20:19:04 -07:00
pci_iomap.h	[PARISC] fix compile break caused by iomap: make IOPORT/PCI mapping functions conditional	2012-02-27 09:43:30 -06:00
percpu.h
pgalloc.h
pgtable-nopmd.h
pgtable-nopud.h
pgtable.h	mm: soft-dirty bits for user memory changes tracking	2013-07-03 16:07:26 -07:00
ptrace.h	asm-generic/ptrace.h: start a common low level ptrace helper	2011-05-26 17:12:36 -07:00
resource.h	UAPI: (Scripted) Disintegrate include/asm-generic	2012-10-04 18:20:15 +01:00
rtc.h
rwsem.h	Hexagon: Add locking types and functions	2011-11-01 07:34:20 -07:00
scatterlist.h
sections.h
segment.h
serial.h
siginfo.h	UAPI: (Scripted) Disintegrate include/asm-generic	2012-10-04 18:20:15 +01:00
signal.h	unify default ptrace_signal_deliver	2012-11-29 00:01:23 -05:00
sizes.h	ARM: 7430/1: sizes.h: move from asm-generic to <linux/sizes.h>	2012-06-28 17:14:34 +01:00
spinlock.h
statfs.h	UAPI: (Scripted) Disintegrate include/asm-generic	2012-10-04 18:20:15 +01:00
string.h
switch_to.h	Split the switch_to() wrapper out of asm-generic/system.h	2012-03-28 18:30:03 +01:00
syscall.h	asm/syscall.h: add syscall_get_arch	2012-04-14 11:13:19 +10:00
syscalls.h	burying unused conditionals	2013-02-14 09:21:15 -05:00
termios-base.h
termios.h	UAPI: (Scripted) Disintegrate include/asm-generic	2012-10-04 18:20:15 +01:00
timex.h
tlb.h	arch, mm: Remove tlb_fast_mode()	2013-06-06 10:07:26 +09:00
tlbflush.h	BUG: headers with BUG/BUG_ON etc. need linux/bug.h	2012-03-04 17:54:34 -05:00
topology.h
trace_clock.h	tracing,x86: Add a TSC trace_clock	2012-11-13 15:48:27 -05:00
uaccess-unaligned.h
uaccess.h	asm-generic: uaccess s/might_sleep/might_fault/	2013-05-28 09:41:05 +02:00
unaligned.h
unistd.h	We get rid of the general module prefix confusion with a binary config option,	2013-05-05 10:58:06 -07:00
user.h
vga.h
vmlinux.lds.h	Finally eradicate CONFIG_HOTPLUG	2013-06-03 14:20:18 -07:00
word-at-a-time.h	word-at-a-time: make the interfaces truly generic	2012-05-26 11:33:40 -07:00
xor.h	asm-generic: xor: mark static functions as __maybe_unused	2012-10-03 21:21:06 +02:00