Current code assumes that cpumask of cpus sharing a l2-cache mask will always be a superset of cpu_sibling_mask.
Lets stop that assumption. cpu_l2_cache_mask is a superset of cpu_sibling_mask if and only if shared_caches is set. Cc: linuxppc-dev <[email protected]> Cc: LKML <[email protected]> Cc: Michael Ellerman <[email protected]> Cc: Nicholas Piggin <[email protected]> Cc: Anton Blanchard <[email protected]> Cc: Oliver O'Halloran <[email protected]> Cc: Nathan Lynch <[email protected]> Cc: Michael Neuling <[email protected]> Cc: Gautham R Shenoy <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Valentin Schneider <[email protected]> Cc: Jordan Niethe <[email protected]> Signed-off-by: Srikar Dronamraju <[email protected]> --- Changelog v1 -> v2: Set cpumask after verifying l2-cache. (Gautham) arch/powerpc/kernel/smp.c | 28 +++++++++++++++------------- 1 file changed, 15 insertions(+), 13 deletions(-) diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c index da27f6909be1..d997c7411664 100644 --- a/arch/powerpc/kernel/smp.c +++ b/arch/powerpc/kernel/smp.c @@ -1194,6 +1194,7 @@ static bool update_mask_by_l2(int cpu, struct cpumask *(*mask_fn)(int)) if (!l2_cache) return false; + cpumask_set_cpu(cpu, mask_fn(cpu)); for_each_cpu(i, cpu_online_mask) { /* * when updating the marks the current CPU has not been marked @@ -1276,29 +1277,30 @@ static void add_cpu_to_masks(int cpu) * add it to it's own thread sibling mask. */ cpumask_set_cpu(cpu, cpu_sibling_mask(cpu)); + cpumask_set_cpu(cpu, cpu_core_mask(cpu)); for (i = first_thread; i < first_thread + threads_per_core; i++) if (cpu_online(i)) set_cpus_related(i, cpu, cpu_sibling_mask); add_cpu_to_smallcore_masks(cpu); - /* - * Copy the thread sibling mask into the cache sibling mask - * and mark any CPUs that share an L2 with this CPU. - */ - for_each_cpu(i, cpu_sibling_mask(cpu)) - set_cpus_related(cpu, i, cpu_l2_cache_mask); update_mask_by_l2(cpu, cpu_l2_cache_mask); - /* - * Copy the cache sibling mask into core sibling mask and mark - * any CPUs on the same chip as this CPU. - */ - for_each_cpu(i, cpu_l2_cache_mask(cpu)) - set_cpus_related(cpu, i, cpu_core_mask); + if (pkg_id == -1) { + struct cpumask *(*mask)(int) = cpu_sibling_mask; + + /* + * Copy the sibling mask into core sibling mask and + * mark any CPUs on the same chip as this CPU. + */ + if (shared_caches) + mask = cpu_l2_cache_mask; + + for_each_cpu(i, mask(cpu)) + set_cpus_related(cpu, i, cpu_core_mask); - if (pkg_id == -1) return; + } for_each_cpu(i, cpu_online_mask) if (get_physical_package_id(i) == pkg_id) -- 2.18.2
