On Monday, July 15, 2013 11:50:24 AM Srivatsa S. Bhat wrote: > On 07/12/2013 12:36 PM, Viresh Kumar wrote: > > On 12 July 2013 03:45, Srivatsa S. Bhat > > <srivatsa.b...@linux.vnet.ibm.com> wrote: > >> The call to cpufreq_update_policy() is placed in the CPU hotplug callback > >> of cpufreq_stats, which has a higher priority than the CPU hotplug callback > >> of cpufreq-core. As a result, during CPU_ONLINE/CPU_ONLINE_FROZEN, we end > >> up > >> calling cpufreq_update_policy() *before* calling cpufreq_add_dev() ! > >> And for uninitialized CPUs, it just returns silently, not doing anything. > > > > Hmm.. > > > >> To add to it, cpufreq_stats is not even the right place to call > >> cpufreq_update_policy() to begin with. The cpufreq core ought to handle > >> this in its own callback, from an elegance/relevance perspective. > >> > >> So move the invocation of cpufreq_update_policy() to cpufreq_cpu_callback, > >> and place it *after* cpufreq_add_dev(). > >> > >> Signed-off-by: Srivatsa S. Bhat <srivatsa.b...@linux.vnet.ibm.com> > >> --- > >> > >> drivers/cpufreq/cpufreq.c | 1 + > >> drivers/cpufreq/cpufreq_stats.c | 6 ------ > >> 2 files changed, 1 insertion(+), 6 deletions(-) > >> > >> diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c > >> index ccc6eab..f8c3100 100644 > >> --- a/drivers/cpufreq/cpufreq.c > >> +++ b/drivers/cpufreq/cpufreq.c > >> @@ -1943,6 +1943,7 @@ static int __cpuinit cpufreq_cpu_callback(struct > >> notifier_block *nfb, > >> case CPU_ONLINE: > >> case CPU_ONLINE_FROZEN: > >> cpufreq_add_dev(dev, NULL); > >> + cpufreq_update_policy(cpu); > > > > Do we need to call this for every hotplug of cpu? I am not > > talking about suspend/resume here. > > > > I don't think we need to, but I think it would be better to postpone > optimizations until all the cpufreq regressions get fixed. Later perhaps > we could revisit these minor optimizations if desired.
Agreed. Thanks, Rafael -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
