Re: next-20090202: task kmemleak:763 blocked for more than 120seconds.

From: Catalin Marinas
Date: Tue Feb 03 2009 - 07:32:11 EST


On Mon, 2009-02-02 at 13:57 -0800, Mandeep Singh Baines wrote:
> The hung_task timeout is now 480 seconds because of sys_sync:
>
> http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=fb822db465bd9fd4208eef1af4490539b236c54e
>
> But are there are really any other tasks which call
> schedule_timeout_uninterruptibl() for with a timeout >480 seconds?
>
> Right now kmemleak appears to be the only exception. (A quick grep didn't turn
> anything up.) And it is trivial to change kmemleak to use INTERRUPTIBLE.
> Might even be a nice feature. You could stop it faster that way.

I changed the code as below as it makes more sense:

--- a/mm/kmemleak.c
+++ b/mm/kmemleak.c
@@ -1044,6 +1044,7 @@ static int kmemleak_scan_thread(void *arg)

while (!kthread_should_stop()) {
struct kmemleak_object *object;
+ signed long timeout = jiffies_scan_wait;

mutex_lock(&scan_mutex);

@@ -1069,7 +1070,8 @@ static int kmemleak_scan_thread(void *arg)

mutex_unlock(&scan_mutex);
/* wait before the next scan */
- schedule_timeout_uninterruptible(jiffies_scan_wait);
+ while (timeout && !kthread_should_stop())
+ timeout = schedule_timeout_interruptible(timeout);
}

pr_info("kmemleak: Automatic memory scanning thread ended\n");

--
Catalin

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