Re: [PATCH v2] kvm: remove dependence on delay-accounting

From: Peter Zijlstra
Date: Mon Jan 16 2012 - 08:34:06 EST


On Sat, 2012-01-14 at 20:30 +0400, Konstantin Khlebnikov wrote:
> KVM selects delay-accounting only to get sched-info for steal-time accounting.
> Meanwhile delay-accounting can be disabled by boot option. This is ridiculous.
>
> This patch adds internal boolean option CONFIG_TASK_SCHED_INFO to enable only
> task->sched_info and its collecting inside scheduler.

Urgh, more stupid config knobs, we should be removing them, not adding
moar.

> diff --git a/include/linux/sched.h b/include/linux/sched.h
> index 868cb83..dd5bf78 100644
> --- a/include/linux/sched.h
> +++ b/include/linux/sched.h
> @@ -734,7 +734,6 @@ extern struct user_struct root_user;
>
> struct backing_dev_info;
>
> -#if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
> struct sched_info {
> /* cumulative counters */
> unsigned long pcount; /* # of times run on this cpu */
> @@ -744,7 +743,6 @@ struct sched_info {
> unsigned long long last_arrival,/* when we last ran on a cpu */
> last_queued; /* when we were last queued to run */
> };
> -#endif /* defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT) */

Not having that structure helps with compile errors.

> #ifdef CONFIG_TASK_DELAY_ACCT
> struct task_delay_info {
> @@ -782,7 +780,7 @@ struct task_delay_info {
>
> static inline int sched_info_on(void)
> {
> -#ifdef CONFIG_SCHEDSTATS
> +#if IS_ENABLED(CONFIG_SCHEDSTATS) || IS_ENABLED(CONFIG_KVM)

WTF is IS_ENABLED and why do you use it?


Not much like this stuff.
--
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/