linux-kernel - Re: [PATCH] sched: update last_balance only when actually balanced

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] [day] [month] [year] [list]

Message-ID: <53CE875F.5040007@redhat.com>
Date:	Tue, 22 Jul 2014 11:46:39 -0400
From:	Rik van Riel <riel@...hat.com>
To:	Peter Zijlstra <peterz@...radead.org>
CC:	linux-kernel@...r.kernel.org, Kirill Tkhai <ktkhai@...allels.com>,
	Tim Chen <tim.c.chen@...ux.intel.com>,
	Nicolas Pitre <nicolas.pitre@...aro.org>, mingo@...nel.org,
	pjt@...gle.com
Subject: Re: [PATCH] sched: update last_balance only when actually balanced

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

On 07/22/2014 08:04 AM, Peter Zijlstra wrote:

>> diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index
>> 45943b2..4f7fee2 100644 --- a/kernel/sched/fair.c +++
>> b/kernel/sched/fair.c @@ -7187,7 +7187,9 @@ static void
>> rebalance_domains(struct rq *rq, enum cpu_idle_type idle) */ idle
>> = idle_cpu(cpu) ? CPU_IDLE : CPU_NOT_IDLE; } -			sd->last_balance
>> = jiffies; +			/* Only update if we actually balanced. */ +			if
>> (continue_balancing) +				sd->last_balance = jiffies; interval =
>> get_sd_balance_interval(sd, idle != CPU_IDLE); } if
>> (need_serialize)
> 
> Did you actually see any difference with this patch?
> 
> The reason I'm asking is that the sched_domains are per cpu, so
> the above assignment is only visible to that particular cpu, not
> other cpus.

It was past 2AM, it may have been a placebo effect :)

Back to the drawing board, to figure out why the load balancing code
is not working quite as expected...

- -- 
All rights reversed
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1
Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/

iQEcBAEBAgAGBQJTzodfAAoJEM553pKExN6DR3oH+wVSYjVu6eV1tzaDLw2xSvSl
rO8hC9GtIf3LX8NVp/UTVkQXt7wWDLcpV4f+AO9+ikB9Dk5YD9wfTF6vhZVrP8GV
Zjpd3HvO/H3RYomyDXLbocjZ97JsXBF7kxRWmYw0kixUIzhdt/sZKGc46aQXPnGy
BfcGcYYbBKeFr9rrYTTvHwN5XVB1ZMZBEWiH/6baXGgZ5V/rTdcZDw0VGXailpbn
eM5j33B9gCE6bYxD1uCrfZXdaO4BORCkiqfncpSVqLnl9k7B9HbY44bcbqht/qHy
B/F/7+imlvAfhwfQAhj8EYomaAT2GI8m6Ab7frxagJURJ1McU3r+2dgkkhsSqP8=
=QnLG
-----END PGP SIGNATURE-----
--
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/