From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from imap.sh.mvista.com (unknown [63.81.120.155]) by ozlabs.org (Postfix) with ESMTP id 87575DDEDE for ; Sat, 17 Mar 2007 09:09:41 +1100 (EST) Message-ID: <45FB159B.7020909@ru.mvista.com> Date: Sat, 17 Mar 2007 01:09:31 +0300 From: Sergei Shtylyov MIME-Version: 1.0 To: tglx@linutronix.de Subject: Re: [PATCH] PowerPC: dynamic tick support References: <200611082337.28710.sshtylyov@ru.mvista.com> In-Reply-To: <200611082337.28710.sshtylyov@ru.mvista.com> Content-Type: text/plain; charset=us-ascii; format=flowed Cc: linuxppc-dev@ozlabs.org, greg.weeks@timesys.com List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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(); >