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
..
caching	FS-Cache: Provide proper invalidation	2012-12-20 22:04:07 +00:00
configfs	configfs: convert to umode_t	2012-01-03 22:54:57 -05:00
nfs	SUNRPC: Use gssproxy upcall for server RPCGSS authentication.	2013-04-26 11:41:28 -04:00
pohmelfs	Documentation: Fix multiple typo in Documentation	2012-03-07 16:08:24 +01:00
00-INDEX	Introduce a new file system, Flash-Friendly File System (F2FS), to Linux 3.8.	2012-12-20 13:54:52 -08:00
9p.txt	9p: fix 9p.txt to advertise msize instead of maxdata	2011-10-24 11:13:12 -05:00
adfs.txt	adfs: add hexadecimal filetype suffix option	2011-03-22 17:44:17 -07:00
affs.txt	Documentation: update broken web addresses.	2010-08-04 15:21:40 +02:00
afs.txt	AFS: Documentation updates	2009-08-19 10:40:13 -07:00
autofs4-mount-control.txt	Fix common misspellings	2011-03-31 11:26:23 -03:00
automount-support.txt
befs.txt	Documentation: befs.txt: no maintainer, orphaned	2011-08-13 18:34:03 -07:00
bfs.txt	remove mention of CONFIG_KMOD from documentation	2008-07-22 19:24:29 +10:00
btrfs.txt	btrfs: document mount options in Documentation/fs/btrfs.txt	2013-05-06 15:54:26 -04:00
ceph.txt	ceph: enable/disable dentry complete flags via mount option	2012-01-12 11:00:40 -08:00
cifs.txt
coda.txt
cramfs.txt
debugfs.txt	debugfs: more tightly restrict default mount mode	2012-08-27 13:42:02 -07:00
devpts.txt	Document usage of multiple-instances of devpts	2009-01-02 10:19:36 -08:00
directory-locking	Documentation: Fix up docs still talking about i_sem	2007-05-24 10:16:17 -07:00
dlmfs.txt	Documentation/: it's -> its where appropriate	2010-04-23 02:09:52 +02:00
dnotify.txt	Documentation/fs/: split txt and source files	2010-03-12 15:52:35 -08:00
dnotify_test.c	Documentation/fs/: split txt and source files	2010-03-12 15:52:35 -08:00
ecryptfs.txt	eCryptfs: Move ecryptfs docs into Documentation/filesystems/	2007-07-17 10:23:08 -07:00
efivarfs.txt	efivarfs: Add documentation for the EFI variable filesystem	2012-10-30 10:39:18 +00:00
exofs.txt	exofs: Add option to mount by osdname	2011-03-15 15:02:51 +02:00
ext2.txt	Doc fix: ext2 can only have 32,000 subdirs, not 32,768	2009-06-18 13:03:44 -07:00
ext3.txt	ext3: update documentation with barrier=1 default	2012-04-11 11:12:45 +02:00
ext4.txt	ext4: introduce reserved space	2013-04-09 22:11:22 -04:00
f2fs.txt	f2fs: add remount_fs callback support	2013-06-17 21:17:55 +09:00
fiemap.txt	Documentation/: it's -> its where appropriate	2010-04-23 02:09:52 +02:00
files.txt	Wrap accesses to the fd_sets in struct fdtable	2012-02-19 10:30:52 -08:00
fuse.txt	Documentation/: it's -> its where appropriate	2010-04-23 02:09:52 +02:00
gfs2-glocks.txt	GFS2: Update glock doc to add new stats info	2012-05-10 12:41:40 +01:00
gfs2-uevents.txt	Documentation: Fix multiple typo in Documentation	2012-03-07 16:08:24 +01:00
gfs2.txt	GFS2: Update main gfs2 doc	2012-05-10 11:45:31 +01:00
hfs.txt	Documentation: HFS is orphaned	2011-11-04 12:01:48 -07:00
hfsplus.txt	Documentation: document HFSPlus	2007-07-31 15:39:38 -07:00
hpfs.txt	Documentation/: it's -> its where appropriate	2010-04-23 02:09:52 +02:00
inotify.txt	Documentation: fix inotify source file paths	2011-11-04 12:01:47 -07:00
isofs.txt	Documentation: update broken web addresses.	2010-08-04 15:21:40 +02:00
jfs.txt	jfs: Remove obsolete email address	2012-09-17 12:00:01 -05:00
Locking	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2013-07-03 09:10:19 -07:00
locks.txt	doc: fix broken references	2011-09-27 18:08:04 +02:00
logfs.txt	fix "seperate" typos in comments	2010-05-10 11:56:30 +02:00
Makefile	Documentation/fs/: split txt and source files	2010-03-12 15:52:35 -08:00
mandatory-locking.txt	locks: add warning about mandatory locking races	2007-10-09 18:32:45 -04:00
ncpfs.txt	ncpfs: remove dead URL from documentation	2009-09-23 07:39:42 -07:00
nilfs2.txt	nilfs2: remove resize from unsupported features list	2011-07-13 16:08:59 +09:00
ntfs.txt	Fix common misspellings	2011-03-31 11:26:23 -03:00
ocfs2.txt	ocfs2: clean up mount option about atime in ocfs2.txt	2011-05-23 23:37:12 -07:00
omfs.txt	omfs: add filesystem documentation	2008-07-26 12:00:05 -07:00
path-lookup.txt	Fix common misspellings	2011-03-31 11:26:23 -03:00
porting	[readdir] ->readdir() is gone	2013-06-29 12:57:04 +04:00
proc.txt	mm: soft-dirty bits for user memory changes tracking	2013-07-03 16:07:26 -07:00
qnx6.txt	Documentation: Fix typo in multiple files in Documentation	2012-04-16 14:37:13 +02:00
quota.txt	quota: documentation for sending "below quota" messages via netlink and tiny doc update	2008-08-12 16:07:27 -07:00
ramfs-rootfs-initramfs.txt	Documentation: Fix Broken URL "freshmeat"	2012-02-21 11:43:45 +01:00
relay.txt	relay: add buffer-only channels; useful for early logging	2008-07-26 12:00:04 -07:00
romfs.txt	Documentation/filesystems/romfs.txt: fixing link to genromfs	2011-02-17 22:04:46 +01:00
seq_file.txt	seq_file: use proc_create() in documentation	2009-12-16 07:20:07 -08:00
sharedsubtree.txt	Documentation: Fix trivial typo in filesystems/sharedsubtree.txt	2010-10-25 21:18:21 -04:00
spufs.txt
squashfs.txt	Squashfs: Update documentation to include xattrs	2011-12-30 01:20:24 +00:00
sysfs-pci.txt	PCI: Allow read/write access to sysfs I/O port resources	2010-07-30 09:32:08 -07:00
sysfs-tagging.txt	sysfs-namespaces: add a high-level Documentation file	2010-05-21 09:37:31 -07:00
sysfs.txt	sysfs: propagate umode_t	2012-01-03 22:55:03 -05:00
sysv-fs.txt
tmpfs.txt	mempolicy: document cpuset interaction with tmpfs mpol mount option	2010-05-25 08:06:57 -07:00
ubifs.txt	UBIFS: switch self-check knobs to debugfs	2011-07-04 10:54:28 +03:00
udf.txt	udf: implement mode and dmode mounting options	2009-04-02 12:29:50 +02:00
ufs.txt
vfat.txt	Documentation: update nfs option in filesystem/vfat.txt	2013-04-29 18:28:41 -07:00
vfs.txt	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2013-07-03 09:10:19 -07:00
xfs-delayed-logging-design.txt	Fix common misspellings	2011-03-31 11:26:23 -03:00
xfs-self-describing-metadata.txt	xfs: add metadata CRC documentation	2013-04-27 13:27:43 -05:00
xfs.txt	xfs: disable noattr2/attr2 mount options for CRC enabled filesystems	2013-06-06 10:51:34 -05:00
xip.txt	DOC: update xip method info	2008-11-12 17:17:17 -08:00