From: Sergei Shtylyov <sshtylyov@ru•mvista.com>
To: tglx@linutronix•de
Cc: linuxppc-dev@ozlabs•org, greg.weeks@timesys•com
Subject: Re: [PATCH] PowerPC: dynamic tick support
Date: Sat, 17 Mar 2007 01:09:31 +0300 [thread overview]
Message-ID: <45FB159B.7020909@ru.mvista.com> (raw)
In-Reply-To: <200611082337.28710.sshtylyov@ru.mvista.com>
Hello, I wrote:
> Add dynamic tick support for PowerPC.
[...]
> Known issues:
> 1) with 2.6.18-hrt-dyntick2, dynamic tick mode causes bootup slowdown after the
> HRT mode is entered (it seems to return to normal shortly);
> 2) with 2.6.18-rt7 (plus an extra patch to make it actually working :-) in the
> kernel preemption mode other than RT, that slowdown seems permanent (this
> was not happening with 2.6.18-rt6).
> I don't have time to investigate now, so anybody interested is welcome to...
... but I should have done it. :-/
> or I may even return to this if/when the time permits. :-)
Looks like that was caused by that missing !need_resched_delayed() below.
So, should be fixed with the latest 2.6.21-rc3-rt0 patch...
> arch/powerpc/kernel/idle.c | 4 ++++
> 1 files changed, 4 insertions(+)
>
> Index: linux-2.6/arch/powerpc/kernel/idle.c
> ===================================================================
> --- linux-2.6.orig/arch/powerpc/kernel/idle.c
> +++ linux-2.6/arch/powerpc/kernel/idle.c
> @@ -49,6 +49,8 @@ void cpu_idle(void)
>
> set_thread_flag(TIF_POLLING_NRFLAG);
> while (1) {
> + hrtimer_stop_sched_tick();
> +
> while (!need_resched() && !cpu_should_die()) {
> ppc64_runlatch_off();
>
prev parent reply other threads:[~2007-03-16 22:09 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-11-08 20:37 [PATCH] PowerPC: dynamic tick support Sergei Shtylyov
2007-03-16 22:09 ` Sergei Shtylyov [this message]
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