All threads of a SMT4/SMT8 core can either be part of CPU's coregroup mask or outside the coregroup. Use this relation to reduce the number of iterations needed to find all the CPUs that share the same coregroup
Use a temporary mask to iterate through the CPUs that may share coregroup mask. Also instead of setting one CPU at a time into cpu_coregroup_mask, copy the SMT4/SMT8/submask at one shot. 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: Satheesh Rajendran <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Valentin Schneider <[email protected]> Signed-off-by: Srikar Dronamraju <[email protected]> --- arch/powerpc/kernel/smp.c | 30 ++++++++++++++++++++++-------- 1 file changed, 22 insertions(+), 8 deletions(-) diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c index b48ae4e306d3..bbaea93dc558 100644 --- a/arch/powerpc/kernel/smp.c +++ b/arch/powerpc/kernel/smp.c @@ -1339,19 +1339,33 @@ static inline void add_cpu_to_smallcore_masks(int cpu) static void update_coregroup_mask(int cpu) { - int first_thread = cpu_first_thread_sibling(cpu); + struct cpumask *(*submask_fn)(int) = cpu_sibling_mask; + cpumask_var_t mask; int coregroup_id = cpu_to_coregroup_id(cpu); int i; - cpumask_set_cpu(cpu, cpu_coregroup_mask(cpu)); - for_each_cpu_and(i, cpu_online_mask, cpu_cpu_mask(cpu)) { - int fcpu = cpu_first_thread_sibling(i); + alloc_cpumask_var_node(&mask, GFP_KERNEL, cpu_to_node(cpu)); + cpumask_and(mask, cpu_online_mask, cpu_cpu_mask(cpu)); + + if (shared_caches) + submask_fn = cpu_l2_cache_mask; + + /* Update coregroup mask with all the CPUs that are part of submask */ + or_cpumasks_related(cpu, cpu, submask_fn, cpu_coregroup_mask); + + /* Skip all CPUs already part of coregroup mask */ + cpumask_andnot(mask, mask, cpu_coregroup_mask(cpu)); - if (fcpu == first_thread) - set_cpus_related(cpu, i, cpu_coregroup_mask); - else if (coregroup_id == cpu_to_coregroup_id(i)) - set_cpus_related(cpu, i, cpu_coregroup_mask); + for_each_cpu(i, mask) { + /* Skip all CPUs not part of this coregroup */ + if (coregroup_id == cpu_to_coregroup_id(i)) { + or_cpumasks_related(cpu, i, submask_fn, cpu_coregroup_mask); + cpumask_andnot(mask, mask, submask_fn(i)); + } else { + cpumask_andnot(mask, mask, cpu_coregroup_mask(i)); + } } + free_cpumask_var(mask); } static void add_cpu_to_masks(int cpu) -- 2.17.1
