linux-kernel - Re: [PATCH -tip-rcu] Make rcutorture more vicious: make quiescent rcutorture less power-hungry

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: <1214251374.4440.48.camel@Aeon>
Date:	Mon, 23 Jun 2008 20:02:54 +0000
From:	Darren Hart <dvhltc@...ibm.com>
To:	Arjan van de Ven <arjan@...radead.org>
Cc:	paulmck@...ux.vnet.ibm.com, linux-kernel@...r.kernel.org,
	mingo@...e.hu, josh@...edesktop.org, niv@...ibm.com,
	dino@...ibm.com, akpm@...ux-foundation.org,
	torvalds@...ux-foundation.org, vegard.nossum@...il.com,
	adobriyan@...il.com, oleg@...sign.ru, bunk@...nel.org, rjw@...k.pl
Subject: Re: [PATCH -tip-rcu] Make rcutorture more vicious: make quiescent
	rcutorture less power-hungry

On Mon, 2008-06-23 at 11:07 -0700, Arjan van de Ven wrote:
> On Mon, 23 Jun 2008 17:54:09 +0000
> Darren Hart <dvhltc@...ibm.com> wrote:
> 
> > I'm a little concerned about how this will affect real-time
> > performance, as queueing up lots of timers all at once can lead to
> > long running timer expiration handlers.  If just a schedule_timeout,
> > I suppose we are only looking at a process wakeup, as opposed to a
> > softirq context callback function?
> 
> in reality, the time it takes to deliver the interrupt (including
> waking the CPU up etc), is likely to be an order or two of magnitude
> higher than this kind of code loop.... 

Sure, if we just look at one of them.  Any idea how many such items
we're looking at rounding up to fire at the same time?  Is it dozens,
hundreds, thousands?

Thanks,

-- 
Darren Hart
Real-Time Linux Team Lead
IBM Linux Technology Center

--
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/