linux-kernel - Re: [GIT PULL] omap changes for v2.6.39 merge window

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:	Mon, 04 Apr 2011 12:03:42 +0100
From:	Catalin Marinas <catalin.marinas@....com>
To:	Arnd Bergmann <arnd@...db.de>
Cc:	Russell King - ARM Linux <linux@....linux.org.uk>,
	Nicolas Pitre <nico@...xnic.net>,
	Detlef Vollmann <dv@...lmann.ch>, Ingo Molnar <mingo@...e.hu>,
	david@...g.hm, Tony Lindgren <tony@...mide.com>,
	lkml <linux-kernel@...r.kernel.org>,
	"H. Peter Anvin" <hpa@...or.com>,
	David Brown <davidb@...eaurora.org>,
	linux-omap@...r.kernel.org,
	Linus Torvalds <torvalds@...ux-foundation.org>,
	Thomas Gleixner <tglx@...utronix.de>,
	linux-arm-kernel@...ts.infradead.org
Subject: Re: [GIT PULL] omap changes for v2.6.39 merge window

On Mon, 2011-04-04 at 01:59 +0100, Arnd Bergmann wrote:
> On Sunday 03 April 2011, Russell King - ARM Linux wrote:
> > Then there's those which change the cs->read function pointer at runtime,
...
> > and those which share that pointer with their sched_clock() implementation.
> 
> Abstracting sched_clock() to be run-time selected is something that
> needs to be taken care of. Maybe we could have a generic sched_clock
> implementation that is written on top of clocksource instead of jiffies,
> and always select that on architectures that have a decent clocksource.

On Cortex-A15 with the virtualisation extensions and architected timers
the clocksource is implemented using a physical counter (as we want
wall-clock timing). But for sched_clock() we may want to use a virtual
counter (which is basically an offset from the physical one, set by the
hypervisor during guest OS switching). Marc already posted some patches
for this.

-- 
Catalin


--
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/