linux-kernel - Re: [RFC 4/4] cputime: remove scaling

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: <20130411150637.GB15699@somewhere>
Date:	Thu, 11 Apr 2013 17:06:39 +0200
From:	Frederic Weisbecker <fweisbec@...il.com>
To:	Stanislaw Gruszka <sgruszka@...hat.com>
Cc:	Ingo Molnar <mingo@...nel.org>,
	Peter Zijlstra <peterz@...radead.org>, hpa@...or.com,
	rostedt@...dmis.org, akpm@...ux-foundation.org, tglx@...utronix.de,
	Linus Torvalds <torvalds@...ux-foundation.org>,
	linux-kernel@...r.kernel.org
Subject: Re: [RFC 4/4] cputime: remove scaling

On Thu, Apr 11, 2013 at 10:36:35AM +0200, Stanislaw Gruszka wrote:
> > I really prefer robust kernel side accounting/instrumentation.
> 
> We have CONFIG_IRQ_TIME_ACCOUNTING and CONFIG_VIRT_CPU_ACCOUNTING_GEN.
> Perhaps we can change to use one of those options by default. I wonder
> if the additional performance cost related with them is really something
> that we should care about. Are there any measurement that show those
> will make performance worse ?

CONFIG_IRQ_TIME_ACCOUNTING also make use of scaling. And CONFIG_VIRT_CPU_ACCOUNTING_GEN
involves too much overhead on IO-bound workloads. It's mostly good for
undisturbed userspace bound workloads (few IRQs, few exceptions, few syscalls).
--
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/