KOSAKI Motohiro 1306d603fc proc: partially revert "procfs: provide stack information for threads" ... Commit d899bf7b (procfs: provide stack information for threads) introduced to show stack information in /proc/{pid}/status. But it cause large performance regression. Unfortunately /proc/{pid}/status is used ps command too and ps is one of most important component. Because both to take mmap_sem and page table walk are heavily operation. If many process run, the ps performance is, [before d899bf7b] % perf stat ps >/dev/null Performance counter stats for 'ps': 4090.435806 task-clock-msecs # 0.032 CPUs 229 context-switches # 0.000 M/sec 0 CPU-migrations # 0.000 M/sec 234 page-faults # 0.000 M/sec 8587565207 cycles # 2099.425 M/sec 9866662403 instructions # 1.149 IPC 3789415411 cache-references # 926.409 M/sec 30419509 cache-misses # 7.437 M/sec 128.859521955 seconds time elapsed [after d899bf7b] % perf stat ps > /dev/null Performance counter stats for 'ps': 4305.081146 task-clock-msecs # 0.028 CPUs 480 context-switches # 0.000 M/sec 2 CPU-migrations # 0.000 M/sec 237 page-faults # 0.000 M/sec 9021211334 cycles # 2095.480 M/sec 10605887536 instructions # 1.176 IPC 3612650999 cache-references # 839.160 M/sec 23917502 cache-misses # 5.556 M/sec 152.277819582 seconds time elapsed Thus, this patch revert it. Fortunately /proc/{pid}/task/{tid}/smaps provide almost same information. we can use it. Commit d899bf7b introduced two features: 1) Add the annotattion of [thread stack: xxxx] mark to /proc/{pid}/task/{tid}/maps. 2) Add StackUsage field to /proc/{pid}/status. I only revert (2), because I haven't seen (1) cause regression. Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Stefani Seibold <stefani@seibold.net> Cc: Ingo Molnar <mingo@elte.hu> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Randy Dunlap <randy.dunlap@oracle.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andi Kleen <andi@firstfloor.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		2010-01-11 09:34:06 -08:00
..
caching
configfs
nfs
pohmelfs
00-INDEX	Merge branch 'for-2.6.33' of git://linux-nfs.org/~bfields/linux	2009-12-16 10:43:34 -08:00
9p.txt
adfs.txt
affs.txt
afs.txt
autofs4-mount-control.txt
automount-support.txt
befs.txt
bfs.txt
btrfs.txt
cifs.txt
coda.txt
cramfs.txt
debugfs.txt
dentry-locking.txt
devpts.txt
directory-locking
dlmfs.txt
dnotify.txt
ecryptfs.txt
exofs.txt
ext2.txt
ext3.txt
ext4.txt	ext4: Update documentation to correct the inode_readahead_blks option name	2009-12-24 17:51:42 -05:00
fiemap.txt
files.txt
fuse.txt
gfs2-glocks.txt
gfs2-uevents.txt
gfs2.txt
hfs.txt
hfsplus.txt
hpfs.txt
inotify.txt
isofs.txt
jfs.txt
Locking
locks.txt
mandatory-locking.txt
ncpfs.txt
nilfs2.txt	nilfs2: update mailing list address	2010-01-02 21:47:04 +09:00
ntfs.txt
ocfs2.txt
omfs.txt
porting
proc.txt	proc: partially revert "procfs: provide stack information for threads"	2010-01-11 09:34:06 -08:00
quota.txt
ramfs-rootfs-initramfs.txt
relay.txt
romfs.txt
seq_file.txt	seq_file: use proc_create() in documentation	2009-12-16 07:20:07 -08:00
sharedsubtree.txt
smbfs.txt
spufs.txt
squashfs.txt
sysfs-pci.txt
sysfs.txt	Driver core: driver_attribute parameters can often be const*	2009-12-23 11:23:43 -08:00
sysv-fs.txt
tmpfs.txt
ubifs.txt
udf.txt
ufs.txt
vfat.txt
vfs.txt
xfs.txt
xip.txt