linux-kernel - Re: [patch] rt: sysprof hrtimer fix

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:	Fri, 13 Feb 2009 21:03:08 +0100
From:	Frederic Weisbecker <fweisbec@...il.com>
To:	Ingo Molnar <mingo@...e.hu>
Cc:	Thomas Gleixner <tglx@...utronix.de>,
	Thomas Gleixner <tglx@...x.de>,
	LKML <linux-kernel@...r.kernel.org>,
	rt-users <linux-rt-users@...r.kernel.org>,
	Steven Rostedt <rostedt@...dmis.org>,
	Peter Zijlstra <peterz@...radead.org>,
	Carsten Emde <ce@...g.ch>, Clark Williams <williams@...hat.com>
Subject: Re: [patch] rt: sysprof hrtimer fix

On Fri, Feb 13, 2009 at 01:49:28PM +0100, Ingo Molnar wrote:
> 
> * Frederic Weisbecker <fweisbec@...il.com> wrote:
> 
> > So, just a thing.
> > -rt make the hrtimer's timers running on softirq context because the hrtimer_interrupt
> > doesn't run as a threaded interrupt, and then it is not preemptible right?
> > 
> > In that case, sysprof will continue to run in hardirq context, as before, and
> > it will considerably increase the latency. And that matters here.
> > So I think it is important to put it on the reminder:
> 
> hm, not sure. Do you know it numerically how much worst-case overhead it
> induces?
> 
> 	Ingo

Not at all.
But when I find some time, I will compare some rt average tests with and without sysprof.

--
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/