linux-kernel - Re: [PATCH 4/5] sched: Guarantee new group-entities always have weight

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]

Date:	Thu, 17 Oct 2013 00:22:25 +0200
From:	Peter Zijlstra <peterz@...radead.org>
To:	Paul Turner <pjt@...gle.com>
Cc:	Ben Segall <bsegall@...gle.com>, Ingo Molnar <mingo@...hat.com>,
	LKML <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH 4/5] sched: Guarantee new group-entities always have
 weight

On Wed, Oct 16, 2013 at 03:16:44PM -0700, Paul Turner wrote:
> > Hurm.. this gives new groups a massive weight; nr_cpus * NICE_0. ISTR
> > there being some issues with this; or was that on the wakeup path where
> > a task woke on a cpu who's group entity had '0' load because it used to
> > run on another cpu -- I can't remember.
> 
> This could also arbitrarily be MIN_WEIGHT.
> 
> I don't think it actually matters, in practice the set of conditions
> for this weight to ever see use are very specific (e.g. the race
> described above). Otherwise it's always going to be re-initialized (on
> first actual enqueue) to the right value.  (NICE_0_LOAD seemed to make
> sense since this is what you'd "expect" for a new, single thread,
> autogroup/group.)

Fair enough. Thanks!
--
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/