From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mason Subject: Re: schedule_timeout sleeps too long after dividing CPU frequency Date: Fri, 15 May 2015 12:36:10 +0200 Message-ID: <5555CC1A.5040604@free.fr> References: <555218C7.5050602@free.fr> <20150512155004.GP2067@n2100.arm.linux.org.uk> <555380F8.5050306@free.fr> <5554858A.9010207@free.fr> <20150514115456.GB23999@linux> <55549DEE.6010202@free.fr> <20150514144239.GZ2067@n2100.arm.linux.org.uk> <5555BC7E.7010601@free.fr> <20150515095159.GF2067@n2100.arm.linux.org.uk> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20150515095159.GF2067@n2100.arm.linux.org.uk> Sender: linux-pm-owner@vger.kernel.org List-ID: Content-Type: text/plain; charset="us-ascii" To: Russell King - ARM Linux Cc: Viresh Kumar , Daniel Lezcano , "Rafael J. Wysocki" , Mans Rullgard , Linux ARM , Linux PM , cpufreq On 15/05/2015 11:51, Russell King - ARM Linux wrote: > As you don't say which kernel version you're using, Sorry about that, I thought the patch-generating command I posted conveyed the information. $ git diff v3.14.41 HEAD >tango.patch && xz tango.patch I'm using the 3.14.y branch from linux-stable. > for all we know, you might be using a version which omits some fixes > in this area, such as this one which you really must have if your > timer is operating in period mode: > > fe79a9ba1196 clockevents: Adjust timer interval when frequency changes Hmmm, according to git log, this patch was accepted during the 3.14-rc2 merge window. Why didn't it make it for 3.14? I'll cherry-pick that commit, and report back along with the other tests. By any chance, is there a patch that would allow the platform to get high-resolution timers when using smp_twd? Regards. From mboxrd@z Thu Jan 1 00:00:00 1970 From: slash.tmp@free.fr (Mason) Date: Fri, 15 May 2015 12:36:10 +0200 Subject: schedule_timeout sleeps too long after dividing CPU frequency In-Reply-To: <20150515095159.GF2067@n2100.arm.linux.org.uk> References: <555218C7.5050602@free.fr> <20150512155004.GP2067@n2100.arm.linux.org.uk> <555380F8.5050306@free.fr> <5554858A.9010207@free.fr> <20150514115456.GB23999@linux> <55549DEE.6010202@free.fr> <20150514144239.GZ2067@n2100.arm.linux.org.uk> <5555BC7E.7010601@free.fr> <20150515095159.GF2067@n2100.arm.linux.org.uk> Message-ID: <5555CC1A.5040604@free.fr> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 15/05/2015 11:51, Russell King - ARM Linux wrote: > As you don't say which kernel version you're using, Sorry about that, I thought the patch-generating command I posted conveyed the information. $ git diff v3.14.41 HEAD >tango.patch && xz tango.patch I'm using the 3.14.y branch from linux-stable. > for all we know, you might be using a version which omits some fixes > in this area, such as this one which you really must have if your > timer is operating in period mode: > > fe79a9ba1196 clockevents: Adjust timer interval when frequency changes Hmmm, according to git log, this patch was accepted during the 3.14-rc2 merge window. Why didn't it make it for 3.14? I'll cherry-pick that commit, and report back along with the other tests. By any chance, is there a patch that would allow the platform to get high-resolution timers when using smp_twd? Regards.