diff options
| author | Gautham R. Shenoy <ego@linux.vnet.ibm.com> | 2020-12-10 16:08:59 +0530 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2020-12-11 00:10:25 +1100 |
| commit | 0be47634db0baa9e91c7e635e7e73355d6a5cf43 (patch) | |
| tree | c4d119a67f2fa32d44f2ae4e661d7d92a6f20bf9 /arch/powerpc/include/asm/smp.h | |
| parent | 9538abee18cca70ffd03cef56027388b0c5084cc (diff) | |
powerpc/cacheinfo: Print correct cache-sibling map/list for L2 cache
On POWER platforms where only some groups of threads within a core
share the L2-cache (indicated by the ibm,thread-groups device-tree
property), we currently print the incorrect shared_cpu_map/list for
L2-cache in the sysfs.
This patch reports the correct shared_cpu_map/list on such platforms.
Example:
On a platform with "ibm,thread-groups" set to
00000001 00000002 00000004 00000000
00000002 00000004 00000006 00000001
00000003 00000005 00000007 00000002
00000002 00000004 00000000 00000002
00000004 00000006 00000001 00000003
00000005 00000007
This indicates that threads {0,2,4,6} in the core share the L2-cache
and threads {1,3,5,7} in the core share the L2 cache.
However, without the patch, the shared_cpu_map/list for L2 for CPUs 0,
1 is reported in the sysfs as follows:
/sys/devices/system/cpu/cpu0/cache/index2/shared_cpu_list:0-7
/sys/devices/system/cpu/cpu0/cache/index2/shared_cpu_map:000000,000000ff
/sys/devices/system/cpu/cpu1/cache/index2/shared_cpu_list:0-7
/sys/devices/system/cpu/cpu1/cache/index2/shared_cpu_map:000000,000000ff
With the patch, the shared_cpu_map/list for L2 cache for CPUs 0, 1 is
correctly reported as follows:
/sys/devices/system/cpu/cpu0/cache/index2/shared_cpu_list:0,2,4,6
/sys/devices/system/cpu/cpu0/cache/index2/shared_cpu_map:000000,00000055
/sys/devices/system/cpu/cpu1/cache/index2/shared_cpu_list:1,3,5,7
/sys/devices/system/cpu/cpu1/cache/index2/shared_cpu_map:000000,000000aa
This patch also defines cpu_l2_cache_mask() for !CONFIG_SMP case.
Signed-off-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1607596739-32439-6-git-send-email-ego@linux.vnet.ibm.com
Diffstat (limited to 'arch/powerpc/include/asm/smp.h')
| -rw-r--r-- | arch/powerpc/include/asm/smp.h | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/arch/powerpc/include/asm/smp.h b/arch/powerpc/include/asm/smp.h index 035459ce6a1a..c4e2d53acd2b 100644 --- a/arch/powerpc/include/asm/smp.h +++ b/arch/powerpc/include/asm/smp.h @@ -201,6 +201,10 @@ static inline const struct cpumask *cpu_smallcore_mask(int cpu) return cpumask_of(cpu); } +static inline const struct cpumask *cpu_l2_cache_mask(int cpu) +{ + return cpumask_of(cpu); +} #endif /* CONFIG_SMP */ #ifdef CONFIG_PPC64 |