Re: [PATCH 09/40] autonuma: introduce kthread_bind_node()

From: Rik van Riel
Date: Fri Jun 29 2012 - 11:37:18 EST


On 06/28/2012 08:55 AM, Andrea Arcangeli wrote:

--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1792,7 +1792,7 @@ extern void thread_group_times(struct task_struct *p, cputime_t *ut, cputime_t *
#define PF_SWAPWRITE 0x00800000 /* Allowed to write to swap */
#define PF_SPREAD_PAGE 0x01000000 /* Spread page cache over cpuset */
#define PF_SPREAD_SLAB 0x02000000 /* Spread some slab caches over cpuset */
-#define PF_THREAD_BOUND 0x04000000 /* Thread bound to specific cpu */
+#define PF_THREAD_BOUND 0x04000000 /* Thread bound to specific cpus */
#define PF_MCE_EARLY 0x08000000 /* Early kill for mce process policy */
#define PF_MEMPOLICY 0x10000000 /* Non-default NUMA mempolicy */
#define PF_MUTEX_TESTER 0x20000000 /* Thread belongs to the rt mutex tester */

Changing the semantics of PF_THREAD_BOUND without so much as
a comment in your changelog or buy-in from the scheduler
maintainers is a big no-no.

Is there any reason you even need PF_THREAD_BOUND in your
kernel numa threads?

I do not see much at all in the scheduler code that uses
PF_THREAD_BOUND and it is not clear at all that your
numa threads get any benefit from them...

Why do you think you need it?

--
All rights reversed
--
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/