linux-kernel - Re: [tip:timers/nohz] nohz: Move full nohz kick to its own IPI

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: <20140505150558.GC2099@localhost.localdomain>
Date:	Mon, 5 May 2014 17:06:01 +0200
From:	Frederic Weisbecker <fweisbec@...il.com>
To:	Peter Zijlstra <peterz@...radead.org>
Cc:	linux-kernel@...r.kernel.org, mingo@...nel.org, hpa@...or.com,
	paulmck@...ux.vnet.ibm.com, akpm@...ux-foundation.org,
	khilman@...aro.org, tglx@...utronix.de, axboe@...com,
	linux-tip-commits@...r.kernel.org
Subject: Re: [tip:timers/nohz] nohz: Move full nohz kick to its own IPI

On Mon, May 05, 2014 at 04:58:15PM +0200, Peter Zijlstra wrote:
> On Mon, May 05, 2014 at 04:52:59PM +0200, Frederic Weisbecker wrote:
> > > Should we instead do irq_work_queue_on() ?
> > 
> > I would really much prefer that yeah. But if we do that, expect some added overhead on the local
> > irq_work_queue() path though. irq_work_raise can't use local cmpxchg ops anymore.
> > 
> > Or we can have a different pending raise system for remote irq work.
> > 
> > I can try something.
> 
> Loosing that local cmpxchg shouldn't be a problem, I don't  thnk this is
> a particularly hot path.

Then the conversion is easy since most of the irq work code should
already work for remote queuing.

I'll come up with a patch soon.

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/