mirror of https://lore.kernel.org/lkml/
 help / color / mirror / Atom feed
From: Peter Zijlstra <peterz@infradead.org>
To: Ingo Molnar <mingo@kernel.org>, Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: linux-kernel@vger.kernel.org, Mike Galbraith <efault@gmx.de>,
	Paul Turner <pjt@google.com>, Alex Shi <alex.shi@intel.com>,
	Preeti U Murthy <preeti@linux.vnet.ibm.com>,
	Vincent Guittot <vincent.guittot@linaro.org>,
	Morten Rasmussen <morten.rasmussen@arm.com>,
	Namhyung Kim <namhyung@kernel.org>,
	Joonsoo Kim <js1304@gmail.com>,
	Peter Zijlstra <peterz@infradead.org>
Subject: [PATCH 4/6] sched, fair: Remove duplicate load_per_task computations
Date: Fri, 16 Aug 2013 12:12:25 +0200	[thread overview]
Message-ID: <20130816101545.220866770@infradead.org> (raw)
In-Reply-To: <20130816101221.028189677@chello.nl>

[-- Attachment #1: peterz-more-fbg-cleanups.patch --]
[-- Type: text/plain, Size: 1542 bytes --]

Since we already compute (but don't store) the sgs load_per_task value
in update_sg_lb_stats() we might as well store it and not re-compute
it later on.

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
---
 kernel/sched/fair.c |   13 ++-----------
 1 file changed, 2 insertions(+), 11 deletions(-)

--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -4504,7 +4504,6 @@ static inline void update_sg_lb_stats(st
 {
 	unsigned long nr_running, max_nr_running, min_nr_running;
 	unsigned long load, max_cpu_load, min_cpu_load;
-	unsigned long avg_load_per_task = 0;
 	int i;
 
 	/* Tally up the load of all CPUs in the group */
@@ -4559,9 +4558,9 @@ static inline void update_sg_lb_stats(st
 	 *      the hierarchy?
 	 */
 	if (sgs->sum_nr_running)
-		avg_load_per_task = sgs->sum_weighted_load / sgs->sum_nr_running;
+		sgs->load_per_task = sgs->sum_weighted_load / sgs->sum_nr_running;
 
-	if ((max_cpu_load - min_cpu_load) >= avg_load_per_task &&
+	if ((max_cpu_load - min_cpu_load) >= sgs->load_per_task &&
 	    (max_nr_running - min_nr_running) > 1)
 		sgs->group_imb = 1;
 
@@ -4807,15 +4806,7 @@ static inline void calculate_imbalance(s
 	struct sg_lb_stats *this, *busiest;
 
 	this = &sds->this_stat;
-	if (this->sum_nr_running) {
-		this->load_per_task =
-			this->sum_weighted_load / this->sum_nr_running;
-	}
-
 	busiest = &sds->busiest_stat;
-	/* busiest must have some tasks */
-	busiest->load_per_task =
-		busiest->sum_weighted_load / busiest->sum_nr_running;
 
 	if (busiest->group_imb) {
 		busiest->load_per_task =



  parent reply	other threads:[~2013-08-16 10:23 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-08-16 10:12 [PATCH 0/6] Various load-balance cleanups/optimizations Peter Zijlstra
2013-08-16 10:12 ` [PATCH 1/6] sched: Remove one division operation in find_busiest_queue() Peter Zijlstra
2013-08-16 10:12 ` [PATCH 2/6] sched: Factor out code to should_we_balance() Peter Zijlstra
2013-08-16 10:12 ` [PATCH 3/6] sched: Clean-up struct sd_lb_stat Peter Zijlstra
2013-08-16 10:12 ` Peter Zijlstra [this message]
2013-08-16 10:12 ` [PATCH 5/6] sched, fair: Make group power more consitent Peter Zijlstra
2013-08-19  4:17   ` Preeti U Murthy
2013-08-19 10:30     ` Peter Zijlstra
2013-08-20  5:24       ` Preeti U Murthy
2013-08-16 10:12 ` [PATCH 6/6] sched, fair: Rework and comment the group_imb code Peter Zijlstra
2013-08-16 10:34   ` Peter Zijlstra

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20130816101545.220866770@infradead.org \
    --to=peterz@infradead.org \
    --cc=alex.shi@intel.com \
    --cc=efault@gmx.de \
    --cc=iamjoonsoo.kim@lge.com \
    --cc=js1304@gmail.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mingo@kernel.org \
    --cc=morten.rasmussen@arm.com \
    --cc=namhyung@kernel.org \
    --cc=pjt@google.com \
    --cc=preeti@linux.vnet.ibm.com \
    --cc=vincent.guittot@linaro.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox

Powered by JetHome