linux-kernel - Re: [PATCH v2 2/2] nohz: make nohz

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: <20150408172746.GK5029@twins.programming.kicks-ass.net>
Date:	Wed, 8 Apr 2015 19:27:46 +0200
From:	Peter Zijlstra <peterz@...radead.org>
To:	Chris Metcalf <cmetcalf@...hip.com>
Cc:	Frederic Weisbecker <fweisbec@...il.com>,
	"Paul E. McKenney" <paulmck@...ux.vnet.ibm.com>,
	"Rafael J. Wysocki" <rafael.j.wysocki@...el.com>,
	Martin Schwidefsky <schwidefsky@...ibm.com>,
	Ingo Molnar <mingo@...hat.com>, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2 2/2] nohz: make nohz_full imply isolcpus

On Wed, Apr 08, 2015 at 11:21:56AM -0400, Chris Metcalf wrote:
> Apparently the body of the commit message isn't as clear as it might be :-)
> 
> It does say the same thing, though, basically that if nohz_full DOESN'T
> imply isolcpus, that's a bad thing.  I'm happy to reword the text to avoid
> the double negative and say:
> 
>   nohz_full is only useful with isolcpus also set, since otherwise the
>   scheduler has to run periodically to try to determine whether to steal
>   work from other cores.

But you're doing the reverse! You're setting nohz_full for isolcpus, not
limiting the nohz_full mask to isolcpus.

--
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/