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| author | Srikar Dronamraju <srikar@linux.vnet.ibm.com> | 2020-09-21 12:56:44 +0300 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2020-10-06 15:22:26 +0300 |
| commit | 4ca234a9cbd7c3a656b34dd98c8b156f70ed7849 (patch) | |
| tree | 84674ae66b7c470490aac8012a8b098f95b2db95 /arch/powerpc/include/asm/smp.h | |
| parent | 4bce545903fa0290e011cf118997717f0c4f4d20 (diff) | |
| download | linux-4ca234a9cbd7c3a656b34dd98c8b156f70ed7849.tar.xz | |
powerpc/smp: Stop updating cpu_core_mask
Anton Blanchard reported that his 4096 vcpu KVM guest took around 30
minutes to boot. He also analyzed it to the time taken to iterate while
setting the cpu_core_mask.
Further analysis shows that cpu_core_mask and cpu_cpu_mask for any CPU
would be equal on Power. However updating cpu_core_mask took forever to
update as its a per cpu cpumask variable. Instead cpu_cpu_mask was a per
NODE /per DIE cpumask that was shared by all the respective CPUs.
Also cpu_cpu_mask is needed from a scheduler perspective. However
cpu_core_map is an exported symbol. Hence stop updating cpu_core_map
and make it point to cpu_cpu_mask.
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/20200921095653.9701-3-srikar@linux.vnet.ibm.com
Diffstat (limited to 'arch/powerpc/include/asm/smp.h')
| -rw-r--r-- | arch/powerpc/include/asm/smp.h | 5 |
1 files changed, 0 insertions, 5 deletions
diff --git a/arch/powerpc/include/asm/smp.h b/arch/powerpc/include/asm/smp.h index 635bdf947105..b2035b2f57ce 100644 --- a/arch/powerpc/include/asm/smp.h +++ b/arch/powerpc/include/asm/smp.h @@ -121,11 +121,6 @@ static inline struct cpumask *cpu_sibling_mask(int cpu) return per_cpu(cpu_sibling_map, cpu); } -static inline struct cpumask *cpu_core_mask(int cpu) -{ - return per_cpu(cpu_core_map, cpu); -} - static inline struct cpumask *cpu_l2_cache_mask(int cpu) { return per_cpu(cpu_l2_cache_map, cpu); |