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powerpc/smp: Depend on cpu_l1_cache_map when adding CPUs

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Currently on hotplug/hotunplug, CPU iterates through all the CPUs in
its core to find threads in its thread group. However this info is
already captured in cpu_l1_cache_map. Hence reduce iterations and
cleanup add_cpu_to_smallcore_masks function.

Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Tested-by: Satheesh Rajendran <sathnaga@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200921095653.9701-8-srikar@linux.vnet.ibm.com
This commit is contained in:
Srikar Dronamraju 2020-09-21 15:26:49 +05:30 committed by Michael Ellerman
parent 1f3a418104
commit 661e3d42f9
1 changed files with 3 additions and 4 deletions
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7
arch/powerpc/kernel/smp.c
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@ -1285,16 +1285,15 @@ static void remove_cpu_from_masks(int cpu)
static inline void add_cpu_to_smallcore_masks(int cpu)
{
struct cpumask *this_l1_cache_map = per_cpu(cpu_l1_cache_map, cpu);
int i, first_thread = cpu_first_thread_sibling(cpu);
int i;
if (!has_big_cores)
return;
cpumask_set_cpu(cpu, cpu_smallcore_mask(cpu));
for (i = first_thread; i < first_thread + threads_per_core; i++) {
if (cpu_online(i) && cpumask_test_cpu(i, this_l1_cache_map))
for_each_cpu(i, per_cpu(cpu_l1_cache_map, cpu)) {
if (cpu_online(i))
set_cpus_related(i, cpu, cpu_smallcore_mask);
}
}