| Message ID | 20170608075513.12475-2-dietmar.eggemann@arm.com (mailing list archive) |
|---|---|
| State | Not Applicable, archived |
| Headers | show |
On 8 June 2017 at 09:55, Dietmar Eggemann <dietmar.eggemann@arm.com> wrote: > This patch prepares the actual implementation of the frequency-invariant > load-tracking support provided in the next patch ("drivers > base/arch_topology: frequency-invariant load-tracking support"). > > The maximum supported frequency of a cpu (policy->cpuinfo.max_freq) has > to be retrieved for frequency-invariant load-tracking. > > This can be achieved by coding this functionality into the existing > cpufreq policy notifier (init_cpu_capacity_notifier) which is currently > only used for setting up dt-based cpu capacities (cpu node property > capacity-dmips-mhz). > > But frequency-invariant load-tracking has to work whether cpu capacity > dt-parsing succeeded or not. > > Change init_cpu_capacity_notifier in such a way that even if the parsing > of the cpu capacity information failed the notifier is called for each > cpufreq policy to be able to set the maximum supported frequency. > > The exit condition in register_cpufreq_notifier() now only tests for > !acpi_disabled because for frequency invariance the cpufreq policy > notifier has to be enabled even if u32 *raw_capacity is NULL which > occurs when there is no capacity-dmips-mhz property in the dt file or > when the allocation for raw_capacity[cpu] has failed. > > The continue statement in init_cpu_capacity_callback() makes sure that > we don't go on calculating capacity_scale in case the capacity parsing > failed. It should be a break rather a continue here but the next patch > introduces code to set the per-cpu variable max_freq in this > for_each_cpu loop before the check if cap_parsing_failed so it has to > be a continue. > > Cc: Catalin Marinas <catalin.marinas@arm.com> > Cc: Will Deacon <will.deacon@arm.com> > Cc: Russell King <linux@arm.linux.org.uk> > Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> > Cc: Juri Lelli <juri.lelli@arm.com> > Signed-off-by: Dietmar Eggemann <dietmar.eggemann@arm.com> Acked-by: Vincent Guittot <vincent.guittot@linaro.org>
diff --git a/drivers/base/arch_topology.c b/drivers/base/arch_topology.c index d1c33a85059e..272831c89feb 100644 --- a/drivers/base/arch_topology.c +++ b/drivers/base/arch_topology.c @@ -173,7 +173,7 @@ init_cpu_capacity_callback(struct notifier_block *nb, struct cpufreq_policy *policy = data; int cpu; - if (cap_parsing_failed || cap_parsing_done) + if (cap_parsing_done) return 0; switch (val) { @@ -185,13 +185,17 @@ init_cpu_capacity_callback(struct notifier_block *nb, cpus_to_visit, policy->related_cpus); for_each_cpu(cpu, policy->related_cpus) { + if (cap_parsing_failed) + continue; raw_capacity[cpu] = topology_get_cpu_scale(NULL, cpu) * policy->cpuinfo.max_freq / 1000UL; capacity_scale = max(raw_capacity[cpu], capacity_scale); } if (cpumask_empty(cpus_to_visit)) { - topology_normalize_cpu_scale(); - kfree(raw_capacity); + if (!cap_parsing_failed) { + topology_normalize_cpu_scale(); + kfree(raw_capacity); + } pr_debug("cpu_capacity: parsing done\n"); cap_parsing_done = true; schedule_work(&parsing_done_work); @@ -211,7 +215,7 @@ static int __init register_cpufreq_notifier(void) * until we have the necessary code to parse the cpu capacity, so * skip registering cpufreq notifier. */ - if (!acpi_disabled || !raw_capacity) + if (!acpi_disabled) return -EINVAL; if (!alloc_cpumask_var(&cpus_to_visit, GFP_KERNEL)) {
This patch prepares the actual implementation of the frequency-invariant load-tracking support provided in the next patch ("drivers base/arch_topology: frequency-invariant load-tracking support"). The maximum supported frequency of a cpu (policy->cpuinfo.max_freq) has to be retrieved for frequency-invariant load-tracking. This can be achieved by coding this functionality into the existing cpufreq policy notifier (init_cpu_capacity_notifier) which is currently only used for setting up dt-based cpu capacities (cpu node property capacity-dmips-mhz). But frequency-invariant load-tracking has to work whether cpu capacity dt-parsing succeeded or not. Change init_cpu_capacity_notifier in such a way that even if the parsing of the cpu capacity information failed the notifier is called for each cpufreq policy to be able to set the maximum supported frequency. The exit condition in register_cpufreq_notifier() now only tests for !acpi_disabled because for frequency invariance the cpufreq policy notifier has to be enabled even if u32 *raw_capacity is NULL which occurs when there is no capacity-dmips-mhz property in the dt file or when the allocation for raw_capacity[cpu] has failed. The continue statement in init_cpu_capacity_callback() makes sure that we don't go on calculating capacity_scale in case the capacity parsing failed. It should be a break rather a continue here but the next patch introduces code to set the per-cpu variable max_freq in this for_each_cpu loop before the check if cap_parsing_failed so it has to be a continue. Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Russell King <linux@arm.linux.org.uk> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Juri Lelli <juri.lelli@arm.com> Signed-off-by: Dietmar Eggemann <dietmar.eggemann@arm.com> --- drivers/base/arch_topology.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-)