From bb1fbdd3c3fd12b612c7d8cdf13bd6bfeebdefa3 Mon Sep 17 00:00:00 2001 From: Morten Rasmussen Date: Fri, 20 Jul 2018 14:32:32 +0100 Subject: sched/topology, drivers/base/arch_topology: Rebuild the sched_domain hierarchy when capacities change The setting of SD_ASYM_CPUCAPACITY depends on the per-CPU capacities. These might not have their final values when the hierarchy is initially built as the values depend on cpufreq to be initialized or the values being set through sysfs. To ensure that the flags are set correctly we need to rebuild the sched_domain hierarchy whenever the reported per-CPU capacity (arch_scale_cpu_capacity()) changes. This patch ensure that a full sched_domain rebuild happens when CPU capacity changes occur. Signed-off-by: Morten Rasmussen Signed-off-by: Peter Zijlstra (Intel) Cc: Greg Kroah-Hartman Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: dietmar.eggemann@arm.com Cc: valentin.schneider@arm.com Cc: vincent.guittot@linaro.org Link: http://lkml.kernel.org/r/1532093554-30504-3-git-send-email-morten.rasmussen@arm.com Signed-off-by: Ingo Molnar --- drivers/base/arch_topology.c | 26 ++++++++++++++++++++++++++ 1 file changed, 26 insertions(+) (limited to 'drivers') diff --git a/drivers/base/arch_topology.c b/drivers/base/arch_topology.c index e7cb0c6ade81..edfcf8d982e4 100644 --- a/drivers/base/arch_topology.c +++ b/drivers/base/arch_topology.c @@ -15,6 +15,7 @@ #include #include #include +#include DEFINE_PER_CPU(unsigned long, freq_scale) = SCHED_CAPACITY_SCALE; @@ -47,6 +48,9 @@ static ssize_t cpu_capacity_show(struct device *dev, return sprintf(buf, "%lu\n", topology_get_cpu_scale(NULL, cpu->dev.id)); } +static void update_topology_flags_workfn(struct work_struct *work); +static DECLARE_WORK(update_topology_flags_work, update_topology_flags_workfn); + static ssize_t cpu_capacity_store(struct device *dev, struct device_attribute *attr, const char *buf, @@ -72,6 +76,8 @@ static ssize_t cpu_capacity_store(struct device *dev, topology_set_cpu_scale(i, new_capacity); mutex_unlock(&cpu_scale_mutex); + schedule_work(&update_topology_flags_work); + return count; } @@ -96,6 +102,25 @@ static int register_cpu_capacity_sysctl(void) } subsys_initcall(register_cpu_capacity_sysctl); +static int update_topology; + +int topology_update_cpu_topology(void) +{ + return update_topology; +} + +/* + * Updating the sched_domains can't be done directly from cpufreq callbacks + * due to locking, so queue the work for later. + */ +static void update_topology_flags_workfn(struct work_struct *work) +{ + update_topology = 1; + rebuild_sched_domains(); + pr_debug("sched_domain hierarchy rebuilt, flags updated\n"); + update_topology = 0; +} + static u32 capacity_scale; static u32 *raw_capacity; @@ -201,6 +226,7 @@ init_cpu_capacity_callback(struct notifier_block *nb, if (cpumask_empty(cpus_to_visit)) { topology_normalize_cpu_scale(); + schedule_work(&update_topology_flags_work); free_raw_capacity(); pr_debug("cpu_capacity: parsing done\n"); schedule_work(&parsing_done_work); -- cgit