linux-kernel - [PATCH] [91/275] sched: Give CPU bound RT tasks preference

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20110330210529.7CCF93E1A05@tassilo.jf.intel.com>
Date:	Wed, 30 Mar 2011 14:05:29 -0700 (PDT)
From:	Andi Kleen <andi@...stfloor.org>
To:	srostedt@...hat.com, rostedt@...dmis.org, a.p.zijlstra@...llo.nl,
	ak@...ux.intel.com, ghaskins@...ell.com, mingo@...e.hu,
	efault@....de, gregkh@...e.de, linux-kernel@...r.kernel.org,
	stable@...nel.org, tim.bird@...sony.com
Subject: [PATCH] [91/275] sched: Give CPU bound RT tasks preference

2.6.35-longterm review patch.  If anyone has any objections, please let me know.

------------------
From:: Steven Rostedt <srostedt@...hat.com>

Commit: b3bc211cfe7d5fe94b310480d78e00bea96fbf2a upstream

If a high priority task is waking up on a CPU that is running a
lower priority task that is bound to a CPU, see if we can move the
high RT task to another CPU first. Note, if all other CPUs are
running higher priority tasks than the CPU bounded current task,
then it will be preempted regardless.

Signed-off-by: Steven Rostedt <rostedt@...dmis.org>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@...llo.nl>
Signed-off-by: Andi Kleen <ak@...ux.intel.com>
Cc: Gregory Haskins <ghaskins@...ell.com>
LKML-Reference: <20100921024138.888922071@...dmis.org>
Signed-off-by: Ingo Molnar <mingo@...e.hu>
Signed-off-by: Mike Galbraith <efault@....de>
Acked-by: Peter Zijlstra <a.p.zijlstra@...llo.nl>
Signed-off-by: Greg Kroah-Hartman <gregkh@...e.de>
---
 kernel/sched_rt.c |    8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

Index: linux-2.6.35.y/kernel/sched_rt.c
===================================================================
--- linux-2.6.35.y.orig/kernel/sched_rt.c	2011-03-29 23:03:00.009299932 -0700
+++ linux-2.6.35.y/kernel/sched_rt.c	2011-03-29 23:54:59.868470542 -0700
@@ -971,7 +971,8 @@
 	 * For equal prio tasks, we just let the scheduler sort it out.
 	 */
 	if (unlikely(rt_task(rq->curr)) &&
-	    rq->curr->prio < p->prio &&
+	    (rq->curr->rt.nr_cpus_allowed < 2 ||
+	     rq->curr->prio < p->prio) &&
 	    (p->rt.nr_cpus_allowed > 1)) {
 		int cpu = find_lowest_rq(p);
 
@@ -1491,9 +1492,10 @@
 	if (!task_running(rq, p) &&
 	    !test_tsk_need_resched(rq->curr) &&
 	    has_pushable_tasks(rq) &&
+	    p->rt.nr_cpus_allowed > 1 &&
 	    rt_task(rq->curr) &&
-	    rq->curr->prio < p->prio &&
-	    p->rt.nr_cpus_allowed > 1)
+	    (rq->curr->rt.nr_cpus_allowed < 2 ||
+	     rq->curr->prio < p->prio))
 		push_rt_tasks(rq);
 }
 
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/