linux/Documentation/filesystems
Robin Holt 34441427aa revert "procfs: provide stack information for threads" and its fixup commits
Originally, commit d899bf7b ("procfs: provide stack information for
threads") attempted to introduce a new feature for showing where the
threadstack was located and how many pages are being utilized by the
stack.

Commit c44972f1 ("procfs: disable per-task stack usage on NOMMU") was
applied to fix the NO_MMU case.

Commit 89240ba0 ("x86, fs: Fix x86 procfs stack information for threads on
64-bit") was applied to fix a bug in ia32 executables being loaded.

Commit 9ebd4eba7 ("procfs: fix /proc/<pid>/stat stack pointer for kernel
threads") was applied to fix a bug which had kernel threads printing a
userland stack address.

Commit 1306d603f ('proc: partially revert "procfs: provide stack
information for threads"') was then applied to revert the stack pages
being used to solve a significant performance regression.

This patch nearly undoes the effect of all these patches.

The reason for reverting these is it provides an unusable value in
field 28.  For x86_64, a fork will result in the task->stack_start
value being updated to the current user top of stack and not the stack
start address.  This unpredictability of the stack_start value makes
it worthless.  That includes the intended use of showing how much stack
space a thread has.

Other architectures will get different values.  As an example, ia64
gets 0.  The do_fork() and copy_process() functions appear to treat the
stack_start and stack_size parameters as architecture specific.

I only partially reverted c44972f1 ("procfs: disable per-task stack usage
on NOMMU") .  If I had completely reverted it, I would have had to change
mm/Makefile only build pagewalk.o when CONFIG_PROC_PAGE_MONITOR is
configured.  Since I could not test the builds without significant effort,
I decided to not change mm/Makefile.

I only partially reverted 89240ba0 ("x86, fs: Fix x86 procfs stack
information for threads on 64-bit") .  I left the KSTK_ESP() change in
place as that seemed worthwhile.

Signed-off-by: Robin Holt <holt@sgi.com>
Cc: Stefani Seibold <stefani@seibold.net>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-11 17:33:41 -07:00
..
caching CacheFiles: Catch an overly long wait for an old active object 2009-11-19 18:12:05 +00:00
configfs docsrc: build Documentation/ sources 2008-08-12 16:07:30 -07:00
nfs nfsd: 4.1 has an rfc number 2010-01-20 17:17:04 -05:00
pohmelfs Staging: Pohmelfs: Added IO permissions and priorities. 2009-04-17 11:06:30 -07:00
00-INDEX ceph: some documentations fixes 2010-03-29 09:52:11 -07:00
9p.txt 9p: documentation update 2010-04-05 10:37:36 -05:00
Locking dquot: cleanup dquot initialize routine 2010-03-05 00:20:30 +01:00
Makefile Documentation/fs/: split txt and source files 2010-03-12 15:52:35 -08:00
adfs.txt Fix typos in /Documentation : 'U-Z' 2006-11-30 04:58:40 +01:00
affs.txt [PATCH] kernel Doc/ URL corrections 2005-11-22 09:14:30 -08:00
afs.txt AFS: Documentation updates 2009-08-19 10:40:13 -07:00
autofs4-mount-control.txt trivial: Miscellaneous documentation typo fixes 2009-06-12 18:01:47 +02:00
automount-support.txt VFS: Unexport do_kern_mount() and clean up simple_pin_fs() 2006-06-09 09:34:16 -04:00
befs.txt Fix typos in Documentation/: 'Q'-'R' 2006-10-03 22:54:15 +02:00
bfs.txt remove mention of CONFIG_KMOD from documentation 2008-07-22 19:24:29 +10:00
btrfs.txt Btrfs: Add Documentation/filesystem/btrfs.txt, remove old COPYING 2009-01-07 09:54:24 -05:00
ceph.txt ceph: some documentations fixes 2010-03-29 09:52:11 -07:00
cifs.txt
coda.txt
cramfs.txt
debugfs.txt Document the debugfs API 2009-06-06 10:28:14 -06:00
dentry-locking.txt rcu: 1Q2010 update for RCU documentation 2010-01-16 10:25:22 +01:00
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 Fix typos in Documentation/: 'D'-'E' 2006-10-03 22:47:42 +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
exofs.txt trivial: some small fixes in exofs documentation 2009-12-10 09:59:16 +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: make "norecovery" an alias for "noload" 2009-12-10 15:02:52 +01:00
ext4.txt ext4: Update documentation to correct the inode_readahead_blks option name 2009-12-24 17:51:42 -05:00
fiemap.txt trivial: Miscellaneous documentation typo fixes 2009-06-12 18:01:47 +02:00
files.txt fix f_count description in Documentation/filesystems/files.txt 2008-12-31 18:07:42 -05:00
fuse.txt [PATCH] fuse: fix typo 2006-12-30 10:56:45 -08:00
gfs2-glocks.txt GFS2: Update docs 2009-05-19 10:23:23 +01:00
gfs2-uevents.txt GFS2: Add a document explaining GFS2's uevents 2009-08-17 11:11:41 +01:00
gfs2.txt GFS2: Update docs 2009-05-19 10:23:23 +01:00
hfs.txt
hfsplus.txt Documentation: document HFSPlus 2007-07-31 15:39:38 -07:00
hpfs.txt misc doc and kconfig typos 2007-05-09 08:58:15 +02:00
inotify.txt [PATCH] inotify (5/5): update kernel documentation 2006-06-20 05:25:19 -04:00
isofs.txt isofs: let mode and dmode mount options override rock ridge mode setting 2009-06-18 13:03:45 -07:00
jfs.txt JFS: document uid, gid, and umask mount options in jfs.txt 2007-03-09 10:27:31 -06:00
locks.txt Documentation: move locks.txt in filesystems/ 2007-10-09 18:32:45 -04:00
logfs.txt [LogFS] add new flash file system 2009-11-20 20:13:39 +01:00
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: issue discard request after cleaning segments 2010-02-13 12:26:02 +09:00
ntfs.txt NTFS: update homepage 2008-09-02 19:21:37 -07:00
ocfs2.txt ocfs2: Refresh documentation 2009-11-13 15:45:01 -08:00
omfs.txt omfs: add filesystem documentation 2008-07-26 12:00:05 -07:00
porting nfs: new subdir Documentation/filesystems/nfs 2009-10-27 19:34:04 -04:00
proc.txt revert "procfs: provide stack information for threads" and its fixup commits 2010-05-11 17:33:41 -07:00
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 Trivial Documentation/filesystems/ramfs-rootfs-initramfs.txt fix 2008-11-30 11:40:56 -08:00
relay.txt relay: add buffer-only channels; useful for early logging 2008-07-26 12:00:04 -07:00
romfs.txt
seq_file.txt seq_file: use proc_create() in documentation 2009-12-16 07:20:07 -08:00
sharedsubtree.txt add several pieces to shared subtree documentation 2010-03-03 13:00:23 -05:00
smbfs.txt
spufs.txt Fix typos in /Documentation : 'U-Z' 2006-11-30 04:58:40 +01:00
squashfs.txt Squashfs: fix documentation typo, Cramfs filesystem limit is 256 MiB 2009-03-05 00:40:13 +00:00
sysfs-pci.txt trivial: Miscellaneous documentation typo fixes 2009-06-12 18:01:47 +02:00
sysfs.txt Driver core: driver_attribute parameters can often be const* 2009-12-23 11:23:43 -08:00
sysv-fs.txt [PATCH] fs/sysv/: doc cleanup 2006-12-07 08:39:44 -08:00
tmpfs.txt doc: add the documentation for mpol=local 2010-03-24 16:31:21 -07:00
ubifs.txt UBIFS: remove fast unmounting 2009-01-29 16:34:30 +02:00
udf.txt udf: implement mode and dmode mounting options 2009-04-02 12:29:50 +02:00
ufs.txt [PATCH] ufs2 write: mount as rw 2007-02-12 09:48:40 -08:00
vfat.txt vfat: change the default from shortname=lower to shortname=mixed 2009-08-01 21:35:25 +09:00
vfs.txt kill wait_on_page_writeback_range 2009-12-10 15:02:50 +01:00
xfs.txt [XFS] remove restricted chown parameter from xfs linux 2008-10-30 18:30:09 +11:00
xip.txt DOC: update xip method info 2008-11-12 17:17:17 -08:00