diff options
| author | Jiri Slaby <jirislaby@gmail.com> | 2009-08-28 14:08:17 +0200 |
|---|---|---|
| committer | Jiri Slaby <jirislaby@gmail.com> | 2009-11-24 13:31:22 +0100 |
| commit | 51d2d369e4c5c58ebfee4c0047aae02cb8a772fa (patch) | |
| tree | 6f9cd01d7c95fa01ef66550dde1e844e2382ae53 /kernel | |
| parent | 1452d512cae33c92f250849750796dfea2114a8e (diff) | |
core: optimize setrlimit for current task
Don't take tasklist lock for 'current'. It's not needed, since
current->sighand/signal can't disappear.
This improves serlimit called especially via sys_setrlimit.
Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/sys.c | 16 |
1 files changed, 10 insertions, 6 deletions
diff --git a/kernel/sys.c b/kernel/sys.c index 3082eaf4f2c9..605ab9c7be92 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -1250,11 +1250,14 @@ int setrlimit(struct task_struct *tsk, unsigned int resource, if (resource == RLIMIT_NOFILE && new_rlim->rlim_max > sysctl_nr_open) return -EPERM; - /* protect tsk->signal and tsk->sighand from disappearing */ - read_lock(&tasklist_lock); - if (!tsk->sighand) { - retval = -ESRCH; - goto out; + /* optimization: 'current' doesn't need locking, e.g. setrlimit */ + if (tsk != current) { + /* protect tsk->signal and tsk->sighand from disappearing */ + read_lock(&tasklist_lock); + if (!tsk->sighand) { + retval = -ESRCH; + goto out; + } } retval = security_task_setrlimit(tsk, resource, new_rlim); @@ -1294,7 +1297,8 @@ int setrlimit(struct task_struct *tsk, unsigned int resource, update_rlimit_cpu(tsk, new_rlim->rlim_cur); out: - read_unlock(&tasklist_lock); + if (tsk != current) + read_unlock(&tasklist_lock); return retval; } |