From: Robert Love <rml@novell.com>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: linux-kernel@vger.kernel.org, akpm@osdl.org
Subject: [patch] no need to recalculate rq
Date: Thu, 18 Nov 2004 23:39:06 -0500 [thread overview]
Message-ID: <1100839146.20622.22.camel@localhost> (raw)
In-Reply-To: <1100837616.4051.17.camel@localhost.localdomain>
On Thu, 2004-11-18 at 23:13 -0500, Steven Rostedt wrote:
> On lines 3325 and 3330 with the calls to deactivate_task and
> __activate_task respectively. The runqueue is locked at 3316. Can the
> runqueue returned by task_rq change in this setup? If not, what is the
> need for the call to task_rq. Can't rq just be used instead, or is this
> just some extra paranoia?
I don't see any reason that it is needed. The runqueue is locked and
the task is not going anywhere. There is no need to recalculate the
runqueue.
Patch below uses the cached runqueue, rq, saving a few instructions.
Robert Love
no need to call task_rq in setscheduler; just use rq
Signed-Off-By: Robert Love <rml@novell.com>
kernel/sched.c | 4 ++--
1 files changed, 2 insertions(+), 2 deletions(-)
diff -urN linux-2.6.10-rc2/kernel/sched.c linux/kernel/sched.c
--- linux-2.6.10-rc2/kernel/sched.c 2004-11-18 23:32:54.189696376 -0500
+++ linux/kernel/sched.c 2004-11-18 23:35:54.309314032 -0500
@@ -3144,12 +3144,12 @@
}
array = p->array;
if (array)
- deactivate_task(p, task_rq(p));
+ deactivate_task(p, rq);
retval = 0;
oldprio = p->prio;
__setscheduler(p, policy, lp.sched_priority);
if (array) {
- __activate_task(p, task_rq(p));
+ __activate_task(p, rq);
/*
* Reschedule if we are currently running on this runqueue and
* our priority decreased, or if we are not currently running on
next prev parent reply other threads:[~2004-11-19 4:39 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-11-19 4:13 what is the need for task_rq in setscheduler? Steven Rostedt
2004-11-19 4:39 ` Robert Love [this message]
2004-11-19 9:51 ` [patch] no need to recalculate rq Ingo Molnar
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