lkml.org 
[lkml]   [2005]   [Aug]   [25]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
SubjectRe: Redundant up operation in stop_machine.c ?(2.6.12)
From
Date
On Thu, 2005-08-25 at 21:59 +0800, Yingchao Zhou wrote:
> In stop_machine function, there are codes:
> if (ret < 0) {
> stopmachine_set_state(STOPMACHINE_EXIT);
> up(&stopmachine_mutex);
> return ret;
> }
> And in __stop_machine_run ,there are:
> if (!IS_ERR(p)) {
> kthread_bind(p, cpu);
> wake_up_process(p);
> wait_for_completion(&smdata.done);
> }
> up(&stopmachine_mutex);
>
> Is the first up op is really redundant?

Yes, it seems you have found a bug. I tested it (inserting a spurious
failure), and indeed, it gets up'ed twice.

Good catch!
Rusty.

Name: Redundant up operation in stop_machine.c
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (authored)

Yingchao Zhou <puppylove_0814@yahoo.com.cn> noticed that we up() in
stop_machine on failure, and also in the caller (unconditionally).

Index: linux-2.6.13-rc7-git1-Misc/kernel/stop_machine.c
===================================================================
--- linux-2.6.13-rc7-git1-Misc.orig/kernel/stop_machine.c 2005-08-26 11:18:00.000000000 +1000
+++ linux-2.6.13-rc7-git1-Misc/kernel/stop_machine.c 2005-08-26 12:05:01.000000000 +1000
@@ -115,7 +115,6 @@
/* If some failed, kill them all. */
if (ret < 0) {
stopmachine_set_state(STOPMACHINE_EXIT);
- up(&stopmachine_mutex);
return ret;
}

--
A bad analogy is like a leaky screwdriver -- Richard Braakman

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-08-26 04:11    [W:0.031 / U:0.364 seconds]
©2003-2017 Jasper Spaans. hosted at Digital OceanAdvertise on this site