linux-kernel - Re: How to use a different sched

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 for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Thu, 7 May 2009 09:56:39 -0400 (EDT)
From:	Steven Rostedt <rostedt@...dmis.org>
To:	Ingo Molnar <mingo@...e.hu>
cc:	Tim Bird <tim.bird@...sony.com>,
	Ryan Mallon <ryan@...ewatersys.com>,
	Peter Zijlstra <a.p.zijlstra@...llo.nl>,
	Frederic Weisbecker <fweisbec@...il.com>,
	Uwe Kleine-König 
	<u.kleine-koenig@...gutronix.de>,
	linux kernel <linux-kernel@...r.kernel.org>,
	linux-arm-kernel <linux-arm-kernel@...ts.arm.linux.org.uk>
Subject: Re: How to use a different sched_clock() for ftrace on omap?



On Thu, 7 May 2009, Ingo Molnar wrote:

> 
> * Tim Bird <tim.bird@...sony.com> wrote:
> 
> > Hi all,
> > 
> > I've worked up a replacement sched_clock for ftrace on my omap 
> > platform. The current sched_clock, based on the 32K timer, has low 
> > resolution and doesn't provide very useful results.
> 
> hm, why dont you replace the real sched_clock() with it? High 
> resolution sched_clock() gives (much!) better scheduling, better 
> fairness, etc.

Probably because it is board specific, that he can not replace it. But I 
think something like Ryan's idea would be good. Instead of aliasing, just 
make another weak symbol.


unsigned long long __attribute__((weak)) board_sched_clock(void)
{
	[ original sched_clock code ]
}

unsigned long long sched_clock(void)
{
	return board_sched_clock();
}



Then Tim could define a "board_sched_clock" that would be used when that 
board is active.

-- Steve

--
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/