linux-kernel - Re: [PATCH for testing] Re: Decreasing stime running confuses top

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: <200710051707.49458.elendil@planet.nl>
Date:	Fri, 5 Oct 2007 17:07:48 +0200
From:	Frans Pop <elendil@...net.nl>
To:	Chuck Ebbert <cebbert@...hat.com>
Cc:	Christian Borntraeger <borntraeger@...ibm.com>,
	Luca Tettamanti <kronos.it@...il.com>,
	Willy Tarreau <w@....eu>, LKML <linux-kernel@...r.kernel.org>,
	Ilpo Järvinen <ilpo.jarvinen@...sinki.fi>,
	"Alexander E. Patrakov" <patrakov@....usu.ru>,
	Ingo Molnar <mingo@...e.hu>
Subject: Re: [PATCH for testing] Re: Decreasing stime running confuses top

On Friday 05 October 2007, Chuck Ebbert wrote:
> procfs: Don't read runtime twice when computing task's stime
>
> Current code reads p->se.sum_exec_runtime twice and goes through
> multiple type conversions to calculate stime. Read it once and
> skip some of the conversions.
>
> Signed-off-by: Chuck Ebbert <cebbert@...hat.com>

This second patch is a major improvement. But both for kontact and amarok I 
still see stime decreasing occasionally. Sometimes even still quite 
frequently like in this series:

Oct 05 17:00:42 698 178
Oct 05 17:00:43 700 177
Oct 05 17:00:44 700 177
Oct 05 17:00:45 700 177
Oct 05 17:00:46 700 178
Oct 05 17:00:47 700 178
Oct 05 17:00:48 700 177
Oct 05 17:00:49 700 177
Oct 05 17:00:50 700 178
Oct 05 17:00:51 700 178
Oct 05 17:00:52 700 179
Oct 05 17:00:53 698 180
Oct 05 17:00:54 700 179
Oct 05 17:00:55 700 179
Oct 05 17:00:56 700 179
Oct 05 17:00:57 700 179
Oct 05 17:00:58 700 180
Oct 05 17:00:59 700 179

This was after 6 minutes of steady increases.
Should we try a debug patch that shows the raw data behind the calculations?

I'll give the first patch a try next.
-
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/