diff options
| author | Manfred Spraul <manfred@colorfullife.com> | 2004-09-07 17:50:33 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2004-09-07 17:50:33 -0700 |
| commit | 94486dbdabdd094868c8746a66501bfd3fb05ff0 (patch) | |
| tree | 1d6fdf8fe26078ef3363a14b17852390f9d4d37a /include/linux | |
| parent | 5c689659b4056c0b4f70d10654d2c713fe2cf3d6 (diff) | |
[PATCH] fix f_version optimization for get_tgid_list
The kernel contains an optimization that skips the linked list walk in
get_tgid_list for the common case of sequential accesses. Unfortunately
the optimization is buggy (missing NULL pointer check for the result of
find_task_by_pid) and broken (actually - broken twice: the tgid value that
is stored in f_version is always 0 because tgid is overwritten when the
string is created and additionally the common case is not filldir < 0, it's
running out of nr_tgids).
The attached patch fixes these bugs.
Roger Luethi <rl@hellgate.ch> ran a benchmark:
test: top -d 0 -b -n 10 > /dev/null
==> 2.6.8 <==
real 0m19.092s
user 0m5.013s
sys 0m12.622s
==> 2.6.8 + patch-tgid-bugfixes <==
real 0m10.062s
user 0m5.042s
sys 0m4.111s
Signed-Off-By: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'include/linux')
0 files changed, 0 insertions, 0 deletions