* [PATCH mmotm] cgroup: remove rcu_read_lock() from css_get_next()
@ 2009-03-04 4:29 Bharata B Rao
2009-03-04 4:29 ` KAMEZAWA Hiroyuki
0 siblings, 1 reply; 2+ messages in thread
From: Bharata B Rao @ 2009-03-04 4:29 UTC (permalink / raw)
To: Andrew Morton
Cc: linux-kernel, KAMEZAWA Hiroyuki, Balbir Singh, Dhaval Giani,
Paul Menage, Li Zefan
cgroup: remove rcu_read_lock() from css_get_next()
Callers of css_get_next() are already calling css_get_next()
under rcu_read_lock() and hence there there is no need for
css_get_next() to re-acquire rcu_read_lock(). As per the
comments in css_get_next(), let the callers accquire the
rcu_read_lock().
Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com>
---
kernel/cgroup.c | 3 ---
1 file changed, 3 deletions(-)
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -3553,7 +3553,6 @@ css_get_next(struct cgroup_subsys *ss, i
return NULL;
BUG_ON(!ss->use_id);
- rcu_read_lock();
/* fill start point for scan */
tmpid = id;
while (1) {
@@ -3577,8 +3576,6 @@ css_get_next(struct cgroup_subsys *ss, i
/* continue to scan from next id */
tmpid = tmpid + 1;
}
-
- rcu_read_unlock();
return ret;
}
Regards,
Bharata.
^ permalink raw reply [flat|nested] 2+ messages in thread* Re: [PATCH mmotm] cgroup: remove rcu_read_lock() from css_get_next()
2009-03-04 4:29 [PATCH mmotm] cgroup: remove rcu_read_lock() from css_get_next() Bharata B Rao
@ 2009-03-04 4:29 ` KAMEZAWA Hiroyuki
0 siblings, 0 replies; 2+ messages in thread
From: KAMEZAWA Hiroyuki @ 2009-03-04 4:29 UTC (permalink / raw)
To: bharata
Cc: Andrew Morton, linux-kernel, Balbir Singh, Dhaval Giani,
Paul Menage, Li Zefan
On Wed, 4 Mar 2009 09:59:20 +0530
Bharata B Rao <bharata@linux.vnet.ibm.com> wrote:
> cgroup: remove rcu_read_lock() from css_get_next()
>
> Callers of css_get_next() are already calling css_get_next()
> under rcu_read_lock() and hence there there is no need for
> css_get_next() to re-acquire rcu_read_lock(). As per the
> comments in css_get_next(), let the callers accquire the
> rcu_read_lock().
>
> Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com>
Yes, thank you for pointing out. This should be done by caller.
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
> ---
> kernel/cgroup.c | 3 ---
> 1 file changed, 3 deletions(-)
>
> --- a/kernel/cgroup.c
> +++ b/kernel/cgroup.c
> @@ -3553,7 +3553,6 @@ css_get_next(struct cgroup_subsys *ss, i
> return NULL;
>
> BUG_ON(!ss->use_id);
> - rcu_read_lock();
> /* fill start point for scan */
> tmpid = id;
> while (1) {
> @@ -3577,8 +3576,6 @@ css_get_next(struct cgroup_subsys *ss, i
> /* continue to scan from next id */
> tmpid = tmpid + 1;
> }
> -
> - rcu_read_unlock();
> return ret;
> }
>
> Regards,
> Bharata.
>
^ permalink raw reply [flat|nested] 2+ messages in thread
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