Messages in this thread | | | Date | Wed, 20 May 2020 16:11:09 +0530 | From | Viresh Kumar <> | Subject | Re: [RFC PATCH v3 1/2] cpufreq: change '.set_boost' to act on only one policy |
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On 20-05-20, 12:36, Rafael J. Wysocki wrote: > On Wed, May 20, 2020 at 6:59 AM Viresh Kumar <viresh.kumar@linaro.org> wrote: > > > > On 19-05-20, 19:41, Xiongfeng Wang wrote: > > > Macro 'for_each_active_policy()' is defined internally. To avoid some > > > cpufreq driver needing this macro to iterate over all the policies in > > > '.set_boost' callback, we redefine '.set_boost' to act on only one > > > policy and pass the policy as an argument. > > > 'cpufreq_boost_trigger_state()' iterate over all the policies to set > > > boost for the system. This is preparation for adding SW BOOST support > > > for CPPC. > > > > > > Signed-off-by: Xiongfeng Wang <wangxiongfeng2@huawei.com> > > > --- > > > drivers/cpufreq/acpi-cpufreq.c | 4 ++-- > > > drivers/cpufreq/cpufreq.c | 53 +++++++++++++++++++++--------------------- > > > include/linux/cpufreq.h | 2 +- > > > 3 files changed, 30 insertions(+), 29 deletions(-) > > > > > > diff --git a/drivers/cpufreq/acpi-cpufreq.c b/drivers/cpufreq/acpi-cpufreq.c > > > index 289e8ce..b0a9eb5 100644 > > > --- a/drivers/cpufreq/acpi-cpufreq.c > > > +++ b/drivers/cpufreq/acpi-cpufreq.c > > > @@ -126,7 +126,7 @@ static void boost_set_msr_each(void *p_en) > > > boost_set_msr(enable); > > > } > > > > > > -static int set_boost(int val) > > > +static int set_boost(struct cpufreq_policy *policy, int val) > > > { > > > get_online_cpus(); > > > on_each_cpu(boost_set_msr_each, (void *)(long)val, 1); > > > > I think (Rafael can confirm), that you need to update this as well. You don't > > need to run for each cpu now, but for each CPU in the policy. > > Right, the caller will iterate over policies. > > Accordingly, the CPU hotplug locking needs to go to the caller too.
Hmm, why is that required ? Can't we call boost_set_msr_each() for all CPUs of a policy under the locks ? And then let the next call take the lock again ? I thought we don't want a CPU to disappear while we are trying to run boost_set_msr_each() for it (or miss one that just got added) and that should work with the locks being there in this routine.
-- viresh
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