linux-kernel - Re: [PATCH 0/4] pending scheduler updates

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: <1224680712.15904.21.camel@marge.simson.net>
Date:	Wed, 22 Oct 2008 15:05:12 +0200
From:	Mike Galbraith <efault@....de>
To:	Ingo Molnar <mingo@...e.hu>
Cc:	Srivatsa Vaddagiri <vatsa@...ibm.com>,
	Peter Zijlstra <a.p.zijlstra@...llo.nl>,
	LKML <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH 0/4] pending scheduler updates

On Wed, 2008-10-22 at 14:42 +0200, Ingo Molnar wrote:
> * Mike Galbraith <efault@....de> wrote:
> 
> > > > With that patch, pgsql+oltp scales perfectly.
> > > 
> > > hm, tempting.
> > 
> > I disagree.  Postgres's scaling problem is trivially corrected by 
> > twiddling knobs (or whatnot). [...]
> 
> okay, then we need to document it a bit more: what knobs need twiddling 
> to make it scale perfectly?

Twiddle sched_wakeup_granularity_ns or just turn FAIR_SLEEPERS off for
best pgsql+oltp scalability.  Pgsql+oltp collapse is delicate.  It
doesn't take much to send it one way or the other.  Cut preempt a wee
bit, and it can snap right into shape.

I think we need to penalize sleepers a wee bit as load climbs in general
though, everybody begins to like preemption less as load increases.
Mysql+oltp improves as well, and it loves preempt at modest load.

	-Mike

--
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/