arch_update_cpu_topology function is called by the scheduler
before building its sched_domain hierarchy. Prepare the update
of the cpu topology masks in this function in addition to set
it in the the store_cpu_topology which is executed only once per cpu.
Signed-off-by: Vincent Guittot <vincent.guit...@linaro.org>
---
arch/arm/kernel/topology.c | 108 +++++++++++++++++++++++++++++++++++---------
1 files changed, 87 insertions(+), 21 deletions(-)
diff --git a/arch/arm/kernel/topology.c b/arch/arm/kernel/topology.c
index 8200dea..90352cb 100644
--- a/arch/arm/kernel/topology.c
+++ b/arch/arm/kernel/topology.c
@@ -43,12 +43,76 @@
struct cputopo_arm cpu_topology[NR_CPUS];
+/*
+ * cpu topology mask management
+ */
+
+unsigned int advanced_topology = 0;
+
+/*
+ * default topology function
+ */
+
const struct cpumask *cpu_coregroup_mask(int cpu)
{
return &cpu_topology[cpu].core_sibling;
}
/*
+ * clear cpu topology masks
+ */
+static void clear_cpu_topology_mask(void)
+{
+ unsigned int cpuid;
+ for_each_possible_cpu(cpuid) {
+ struct cputopo_arm *cpuid_topo = &(cpu_topology[cpuid]);
+ cpumask_clear(&cpuid_topo->core_sibling);
+ cpumask_clear(&cpuid_topo->thread_sibling);
+ }
+ smp_wmb();
+}
+
+/*
+ * default_cpu_topology_mask set the core and thread mask as described in the
+ * ARM ARM
+ */
+static inline void default_cpu_topology_mask(unsigned int cpuid)
+{
+ struct cputopo_arm *cpuid_topo = &cpu_topology[cpuid];
+ unsigned int cpu;
+
+ for_each_possible_cpu(cpu) {
+ struct cputopo_arm *cpu_topo = &cpu_topology[cpu];
+
+ if (cpuid_topo->socket_id == cpu_topo->socket_id) {
+ cpumask_set_cpu(cpuid, &cpu_topo->core_sibling);
+ if (cpu != cpuid)
+ cpumask_set_cpu(cpu,
+ &cpuid_topo->core_sibling);
+
+ if (cpuid_topo->core_id == cpu_topo->core_id) {
+ cpumask_set_cpu(cpuid,
+ &cpu_topo->thread_sibling);
+ if (cpu != cpuid)
+ cpumask_set_cpu(cpu,
+ &cpuid_topo->thread_sibling);
+ }
+ }
+ }
+ smp_wmb();
+}
+
+static void normal_cpu_topology_mask(void)
+{
+ unsigned int cpuid;
+
+ for_each_possible_cpu(cpuid) {
+ default_cpu_topology_mask(cpuid);
+ }
+ smp_wmb();
+}
+
+/*
* store_cpu_topology is called at boot when only one cpu is running
* and with the mutex cpu_hotplug.lock locked, when several cpus have booted,
* which prevents simultaneous write access to cpu_topology array
@@ -57,7 +121,6 @@ void store_cpu_topology(unsigned int cpuid)
{
struct cputopo_arm *cpuid_topo = &cpu_topology[cpuid];
unsigned int mpidr;
- unsigned int cpu;
/* If the cpu topology has been already set, just return */
if (cpuid_topo->core_id != -1)
@@ -99,26 +162,11 @@ void store_cpu_topology(unsigned int cpuid)
cpuid_topo->socket_id = -1;
}
- /* update core and thread sibling masks */
- for_each_possible_cpu(cpu) {
- struct cputopo_arm *cpu_topo = &cpu_topology[cpu];
-
- if (cpuid_topo->socket_id == cpu_topo->socket_id) {
- cpumask_set_cpu(cpuid, &cpu_topo->core_sibling);
- if (cpu != cpuid)
- cpumask_set_cpu(cpu,
- &cpuid_topo->core_sibling);
-
- if (cpuid_topo->core_id == cpu_topo->core_id) {
- cpumask_set_cpu(cpuid,
- &cpu_topo->thread_sibling);
- if (cpu != cpuid)
- cpumask_set_cpu(cpu,
- &cpuid_topo->thread_sibling);
- }
- }
- }
- smp_wmb();
+ /*
+ * The core and thread sibling masks can also be updated during the
+ * call of arch_update_cpu_topology
+ */
+ default_cpu_topology_mask(cpuid);
printk(KERN_INFO "CPU%u: thread %d, cpu %d, socket %d, mpidr %x\n",
cpuid, cpu_topology[cpuid].thread_id,
@@ -127,6 +175,24 @@ void store_cpu_topology(unsigned int cpuid)
}
/*
+ * arch_update_cpu_topology is called by the scheduler before building
+ * a new sched_domain hierarchy.
+ */
+int arch_update_cpu_topology(void)
+{
+ if (!advanced_topology)
+ return 0;
+
+ /* clear core mask */
+ clear_cpu_topology_mask();
+
+ /* update core and thread sibling masks */
+ normal_cpu_topology_mask();
+
+ return 1;
+}
+
+/*
* init_cpu_topology is called at boot when only one cpu is running
* which prevent simultaneous write access to cpu_topology array
*/
--
1.7.4.1
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