From: Viresh Kumar <viresh.kumar@linaro.org> To: Saravana Kannan <skannan@codeaurora.org> Cc: "Rafael J . Wysocki" <rjw@rjwysocki.net>, Todd Poynor <toddpoynor@google.com>, "Srivatsa S . Bhat" <srivatsa@mit.edu>, "linux-pm@vger.kernel.org" <linux-pm@vger.kernel.org>, Linux Kernel Mailing List <linux-kernel@vger.kernel.org>, "linux-arm-msm@vger.kernel.org" <linux-arm-msm@vger.kernel.org>, "linux-arm-kernel@lists.infradead.org" <linux-arm-kernel@lists.infradead.org>, Stephen Boyd <sboyd@codeaurora.org> Subject: Re: [PATCH v4 3/5] cpufreq: Don't destroy/realloc policy/sysfs on hotplug/suspend Date: Tue, 12 Aug 2014 14:21:53 +0530 [thread overview] Message-ID: <CAKohpokZjAu5E1=m8LRMb=Z87qV1pdLbwZd7gc-462EuJRU4pg@mail.gmail.com> (raw) In-Reply-To: <53E93FF1.1010809@codeaurora.org> On 12 August 2014 03:43, Saravana Kannan <skannan@codeaurora.org> wrote: > On 08/07/2014 03:48 AM, Viresh Kumar wrote: >>> @@ -1369,24 +1354,15 @@ static int __cpufreq_remove_dev_prepare(struct >>> device *dev, >>> } >>> } >>> >>> - if (!cpufreq_driver->setpolicy) >>> - strncpy(per_cpu(cpufreq_cpu_governor, cpu), >>> - policy->governor->name, CPUFREQ_NAME_LEN); >>> - >> >> >> Why? Probably I did mention this earlier as well? > > > This code is saving the governor name here to restore it when the policy is > created again after suspend/resume or hotplug of all CPUs. Since we no > longer throw away the policy struct, there's no point in doing this. > > I should remove this per cpu variable though. Will do it in v5. Hmm, makes sense. So probably keep this code in this patch and get rid of all uses of 'cpufreq_cpu_governor' in a separate patch. >>> + if (cpus > 1) { >>> + if (cpu == policy->cpu) { >>> + new_cpu = cpumask_any_but(policy->cpus, cpu); >>> + if (new_cpu >= 0) >> >> >> Can this ever be false? > > > If this is the last CPU going down. Can that be true? Its present in (cpus > 1) block :) >>> static int cpufreq_remove_dev(struct device *dev, struct >>> subsys_interface *sif) >>> { >>> unsigned int cpu = dev->id; >>> - int ret; >>> - >>> - if (cpu_is_offline(cpu)) >>> - return 0; >>> + int ret = 0; >>> >>> - ret = __cpufreq_remove_dev_prepare(dev, sif); >>> + if (cpu_online(cpu)) >>> + ret = __cpufreq_remove_dev_prepare(dev, sif); >> >> >> Why do you need a change here? > > > Since we no longer do remove_dev_finish during hotplug, we can't just short > circuit the entire function. We have to finish the remove when the CPU is > hot-removed or when the cpufreq driver is unregistered. I think this is tricky and we must have a clear comment here.. I missed this on my initial reviews..
WARNING: multiple messages have this Message-ID (diff)
From: viresh.kumar@linaro.org (Viresh Kumar) To: linux-arm-kernel@lists.infradead.org Subject: [PATCH v4 3/5] cpufreq: Don't destroy/realloc policy/sysfs on hotplug/suspend Date: Tue, 12 Aug 2014 14:21:53 +0530 [thread overview] Message-ID: <CAKohpokZjAu5E1=m8LRMb=Z87qV1pdLbwZd7gc-462EuJRU4pg@mail.gmail.com> (raw) In-Reply-To: <53E93FF1.1010809@codeaurora.org> On 12 August 2014 03:43, Saravana Kannan <skannan@codeaurora.org> wrote: > On 08/07/2014 03:48 AM, Viresh Kumar wrote: >>> @@ -1369,24 +1354,15 @@ static int __cpufreq_remove_dev_prepare(struct >>> device *dev, >>> } >>> } >>> >>> - if (!cpufreq_driver->setpolicy) >>> - strncpy(per_cpu(cpufreq_cpu_governor, cpu), >>> - policy->governor->name, CPUFREQ_NAME_LEN); >>> - >> >> >> Why? Probably I did mention this earlier as well? > > > This code is saving the governor name here to restore it when the policy is > created again after suspend/resume or hotplug of all CPUs. Since we no > longer throw away the policy struct, there's no point in doing this. > > I should remove this per cpu variable though. Will do it in v5. Hmm, makes sense. So probably keep this code in this patch and get rid of all uses of 'cpufreq_cpu_governor' in a separate patch. >>> + if (cpus > 1) { >>> + if (cpu == policy->cpu) { >>> + new_cpu = cpumask_any_but(policy->cpus, cpu); >>> + if (new_cpu >= 0) >> >> >> Can this ever be false? > > > If this is the last CPU going down. Can that be true? Its present in (cpus > 1) block :) >>> static int cpufreq_remove_dev(struct device *dev, struct >>> subsys_interface *sif) >>> { >>> unsigned int cpu = dev->id; >>> - int ret; >>> - >>> - if (cpu_is_offline(cpu)) >>> - return 0; >>> + int ret = 0; >>> >>> - ret = __cpufreq_remove_dev_prepare(dev, sif); >>> + if (cpu_online(cpu)) >>> + ret = __cpufreq_remove_dev_prepare(dev, sif); >> >> >> Why do you need a change here? > > > Since we no longer do remove_dev_finish during hotplug, we can't just short > circuit the entire function. We have to finish the remove when the CPU is > hot-removed or when the cpufreq driver is unregistered. I think this is tricky and we must have a clear comment here.. I missed this on my initial reviews..
next prev parent reply other threads:[~2014-08-12 8:51 UTC|newest] Thread overview: 205+ messages / expand[flat|nested] mbox.gz Atom feed top 2014-07-10 2:37 [PATCH] cpufreq: Don't destroy/realloc policy/sysfs on hotplug/suspend Saravana Kannan 2014-07-10 2:37 ` Saravana Kannan 2014-07-11 4:18 ` [PATCH v2] " Saravana Kannan 2014-07-11 4:18 ` Saravana Kannan 2014-07-11 6:19 ` Viresh Kumar 2014-07-11 6:19 ` Viresh Kumar 2014-07-11 6:19 ` Viresh Kumar 2014-07-11 9:59 ` skannan 2014-07-11 9:59 ` skannan at codeaurora.org 2014-07-11 9:59 ` skannan 2014-07-11 10:07 ` skannan 2014-07-11 10:07 ` skannan at codeaurora.org 2014-07-11 10:07 ` skannan 2014-07-11 10:52 ` Viresh Kumar 2014-07-11 10:52 ` Viresh Kumar 2014-07-11 10:52 ` Viresh Kumar 2014-07-12 2:44 ` Saravana Kannan 2014-07-12 2:44 ` Saravana Kannan 2014-07-12 2:44 ` Saravana Kannan 2014-07-14 6:09 ` Viresh Kumar 2014-07-14 6:09 ` Viresh Kumar 2014-07-14 6:09 ` Viresh Kumar 2014-07-14 19:08 ` Saravana Kannan 2014-07-14 19:08 ` Saravana Kannan 2014-07-14 19:08 ` Saravana Kannan 2014-07-15 4:35 ` Viresh Kumar 2014-07-15 4:35 ` Viresh Kumar 2014-07-15 4:35 ` Viresh Kumar 2014-07-15 5:36 ` Saravana Kannan 2014-07-15 5:36 ` Saravana Kannan 2014-07-15 5:36 ` Saravana Kannan 2014-07-15 5:52 ` Viresh Kumar 2014-07-15 5:52 ` Viresh Kumar 2014-07-15 5:52 ` Viresh Kumar 2014-07-15 6:58 ` Srivatsa S. Bhat 2014-07-15 6:58 ` Srivatsa S. Bhat 2014-07-15 6:58 ` Srivatsa S. Bhat 2014-07-15 17:35 ` skannan 2014-07-15 17:35 ` skannan at codeaurora.org 2014-07-15 17:35 ` skannan 2014-07-16 7:44 ` Srivatsa S. Bhat 2014-07-16 7:44 ` Srivatsa S. Bhat 2014-07-16 7:44 ` Srivatsa S. Bhat 2014-07-16 5:44 ` Viresh Kumar 2014-07-16 5:44 ` Viresh Kumar 2014-07-16 5:44 ` Viresh Kumar 2014-07-16 7:49 ` Srivatsa S. Bhat 2014-07-16 7:49 ` Srivatsa S. Bhat 2014-07-16 7:49 ` Srivatsa S. Bhat 2014-07-12 3:06 ` Saravana Kannan 2014-07-12 3:06 ` Saravana Kannan 2014-07-12 3:06 ` Saravana Kannan 2014-07-14 6:13 ` Viresh Kumar 2014-07-14 6:13 ` Viresh Kumar 2014-07-14 6:13 ` Viresh Kumar 2014-07-14 19:10 ` Saravana Kannan 2014-07-14 19:10 ` Saravana Kannan 2014-07-14 19:10 ` Saravana Kannan 2014-07-11 7:43 ` Srivatsa S. Bhat 2014-07-11 7:43 ` Srivatsa S. Bhat 2014-07-11 10:02 ` skannan 2014-07-11 10:02 ` skannan at codeaurora.org 2014-07-15 22:47 ` [PATCH v3 0/2] Simplify hotplug/suspend handling Saravana Kannan 2014-07-15 22:47 ` Saravana Kannan 2014-07-15 22:47 ` [PATCH v3 1/2] cpufreq: Don't destroy/realloc policy/sysfs on hotplug/suspend Saravana Kannan 2014-07-15 22:47 ` Saravana Kannan 2014-07-16 0:28 ` Saravana Kannan 2014-07-16 0:28 ` Saravana Kannan 2014-07-16 8:30 ` Viresh Kumar 2014-07-16 8:30 ` Viresh Kumar 2014-07-16 8:30 ` Viresh Kumar 2014-07-16 19:19 ` Saravana Kannan 2014-07-16 19:19 ` Saravana Kannan 2014-07-16 19:19 ` Saravana Kannan 2014-07-16 8:24 ` Viresh Kumar 2014-07-16 8:24 ` Viresh Kumar 2014-07-16 8:24 ` Viresh Kumar 2014-07-16 11:16 ` Srivatsa S. Bhat 2014-07-16 11:16 ` Srivatsa S. Bhat 2014-07-16 11:16 ` Srivatsa S. Bhat 2014-07-16 13:13 ` Viresh Kumar 2014-07-16 13:13 ` Viresh Kumar 2014-07-16 13:13 ` Viresh Kumar 2014-07-16 18:04 ` Srivatsa S. Bhat 2014-07-16 18:04 ` Srivatsa S. Bhat 2014-07-16 18:04 ` Srivatsa S. Bhat 2014-07-16 19:56 ` Saravana Kannan 2014-07-16 19:56 ` Saravana Kannan 2014-07-16 19:56 ` Saravana Kannan 2014-07-17 5:51 ` Viresh Kumar 2014-07-17 5:51 ` Viresh Kumar 2014-07-17 5:51 ` Viresh Kumar 2014-07-16 19:56 ` Saravana Kannan 2014-07-16 19:56 ` Saravana Kannan 2014-07-16 19:56 ` Saravana Kannan 2014-07-17 5:35 ` Viresh Kumar 2014-07-17 5:35 ` Viresh Kumar 2014-07-17 5:35 ` Viresh Kumar 2014-07-18 3:25 ` Saravana Kannan 2014-07-18 3:25 ` Saravana Kannan 2014-07-18 3:25 ` Saravana Kannan 2014-07-18 4:19 ` Viresh Kumar 2014-07-18 4:19 ` Viresh Kumar 2014-07-18 4:19 ` Viresh Kumar 2014-07-16 20:25 ` Saravana Kannan 2014-07-16 20:25 ` Saravana Kannan 2014-07-16 20:25 ` Saravana Kannan 2014-07-16 21:45 ` Saravana Kannan 2014-07-16 21:45 ` Saravana Kannan 2014-07-16 21:45 ` Saravana Kannan 2014-07-17 6:24 ` Viresh Kumar 2014-07-17 6:24 ` Viresh Kumar 2014-07-17 6:24 ` Viresh Kumar 2014-07-16 14:29 ` Dirk Brandewie 2014-07-16 14:29 ` Dirk Brandewie 2014-07-16 15:28 ` Viresh Kumar 2014-07-16 15:28 ` Viresh Kumar 2014-07-16 15:28 ` Viresh Kumar 2014-07-16 19:42 ` Saravana Kannan 2014-07-16 19:42 ` Saravana Kannan 2014-07-16 19:42 ` Saravana Kannan 2014-07-15 22:47 ` [PATCH v3 2/2] cpufreq: Simplify and fix mutual exclusion with hotplug Saravana Kannan 2014-07-15 22:47 ` Saravana Kannan 2014-07-16 8:48 ` Viresh Kumar 2014-07-16 8:48 ` Viresh Kumar 2014-07-16 8:48 ` Viresh Kumar 2014-07-16 19:34 ` Saravana Kannan 2014-07-16 19:34 ` Saravana Kannan 2014-07-16 19:34 ` Saravana Kannan 2014-07-25 1:07 ` [PATCH v4 0/5] Simplify hotplug/suspend handling Saravana Kannan 2014-07-25 1:07 ` Saravana Kannan 2014-07-25 1:07 ` [PATCH v4 1/5] cpufreq: Don't wait for CPU to going offline to restart governor Saravana Kannan 2014-07-25 1:07 ` Saravana Kannan 2014-07-31 20:47 ` Saravana Kannan 2014-07-31 20:47 ` Saravana Kannan 2014-07-25 1:07 ` [PATCH v4 2/5] cpufreq: Keep track of which CPU owns the kobj/sysfs nodes separately Saravana Kannan 2014-07-25 1:07 ` Saravana Kannan 2014-08-07 9:02 ` Viresh Kumar 2014-08-07 9:02 ` Viresh Kumar 2014-08-07 9:02 ` Viresh Kumar 2014-07-25 1:07 ` [PATCH v4 3/5] cpufreq: Don't destroy/realloc policy/sysfs on hotplug/suspend Saravana Kannan 2014-07-25 1:07 ` Saravana Kannan 2014-07-31 21:56 ` Rafael J. Wysocki 2014-07-31 21:56 ` Rafael J. Wysocki 2014-07-31 22:15 ` Saravana Kannan 2014-07-31 22:15 ` Saravana Kannan 2014-07-31 23:48 ` Saravana Kannan 2014-07-31 23:48 ` Saravana Kannan 2014-07-31 23:48 ` Saravana Kannan 2014-08-07 10:51 ` Viresh Kumar 2014-08-07 10:51 ` Viresh Kumar 2014-08-07 10:51 ` Viresh Kumar 2014-08-12 9:17 ` Viresh Kumar 2014-08-12 9:17 ` Viresh Kumar 2014-08-12 9:17 ` Viresh Kumar 2014-08-07 10:48 ` Viresh Kumar 2014-08-07 10:48 ` Viresh Kumar 2014-08-07 10:48 ` Viresh Kumar 2014-08-11 22:13 ` Saravana Kannan 2014-08-11 22:13 ` Saravana Kannan 2014-08-11 22:13 ` Saravana Kannan 2014-08-12 8:51 ` Viresh Kumar [this message] 2014-08-12 8:51 ` Viresh Kumar 2014-08-12 8:51 ` Viresh Kumar 2014-07-25 1:07 ` [PATCH v4 4/5] cpufreq: Properly handle physical CPU hot-add/hot-remove Saravana Kannan 2014-07-25 1:07 ` Saravana Kannan 2014-07-25 1:07 ` Saravana Kannan 2014-08-07 11:02 ` Viresh Kumar 2014-08-07 11:02 ` Viresh Kumar 2014-08-07 11:02 ` Viresh Kumar 2014-08-11 22:15 ` Saravana Kannan 2014-08-11 22:15 ` Saravana Kannan 2014-08-11 22:15 ` Saravana Kannan 2014-07-25 1:07 ` [PATCH v4 5/5] cpufreq: Delete dead code related to policy save/restore Saravana Kannan 2014-07-25 1:07 ` Saravana Kannan 2014-08-07 11:06 ` Viresh Kumar 2014-08-07 11:06 ` Viresh Kumar 2014-08-07 11:06 ` Viresh Kumar 2014-07-29 5:52 ` [PATCH v4 0/5] Simplify hotplug/suspend handling skannan 2014-07-29 5:52 ` skannan at codeaurora.org 2014-07-29 5:52 ` skannan 2014-07-30 0:29 ` Rafael J. Wysocki 2014-07-30 0:29 ` Rafael J. Wysocki 2014-07-31 20:25 ` Saravana Kannan 2014-07-31 20:25 ` Saravana Kannan 2014-08-07 6:04 ` skannan 2014-08-07 6:04 ` skannan at codeaurora.org 2014-10-16 8:53 ` Viresh Kumar 2014-10-16 8:53 ` Viresh Kumar 2014-10-16 8:53 ` Viresh Kumar 2014-10-23 21:41 ` Saravana Kannan 2014-10-23 21:41 ` Saravana Kannan 2014-10-23 21:41 ` Saravana Kannan 2014-07-16 22:02 ` [PATCH] cpufreq: Don't destroy/realloc policy/sysfs on hotplug/suspend Rafael J. Wysocki 2014-07-16 22:02 ` Rafael J. Wysocki 2014-07-16 22:35 ` Saravana Kannan 2014-07-16 22:35 ` Saravana Kannan 2014-07-24 3:02 ` Saravana Kannan 2014-07-24 3:02 ` Saravana Kannan 2014-07-24 5:04 ` Viresh Kumar 2014-07-24 5:04 ` Viresh Kumar 2014-07-24 5:04 ` Viresh Kumar 2014-07-24 9:12 ` skannan 2014-07-24 9:12 ` skannan at codeaurora.org 2014-07-24 9:12 ` skannan
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