From 7efbae90892b7858f1d4873d34ffffbeb460ed8b Mon Sep 17 00:00:00 2001 From: Anju T Date: Mon, 14 Aug 2017 17:12:23 +0530 Subject: [PATCH] powerpc/perf/imc: Fix nest events on muti socket system In a multi node system with discontiguous node ids, nest event values are not showing up properly. eg. lscpu output: NUMA node0 CPU(s): 0-15 NUMA node8 CPU(s): 16-31 Nest event values on such systems can be counted on CPUs <= 15: $./perf stat -e 'nest_powerbus0_imc/PM_PB_CYC/' -C 0-14 -I 1000 sleep 1000 # time counts unit events 1.000294577 30,17,24,42,880 nest_powerbus0_imc/PM_PB_CYC/ But not on CPUs >= 16: $./perf stat -e 'nest_powerbus0_imc/PM_PB_CYC/' -C 16-28 -I 1000 sleep 1000 # time counts unit events 1.000049902 nest_powerbus0_imc/PM_PB_CYC/ This is because, when fetching the reference count, the node id (which may be sparse) is used as the array index, not the node number (which is 0 based and contiguous). Fix it by using the node number as the array index. $./perf stat -e 'nest_powerbus0_imc/PM_PB_CYC/' -C 16-28 -I 1000 sleep 1000 # time counts unit events 1.000241961 26,12,35,28,704 nest_powerbus0_imc/PM_PB_CYC/ Signed-off-by: Anju T Sudhakar [mpe: Change log tweaks for clarity and brevity] Signed-off-by: Michael Ellerman --- arch/powerpc/perf/imc-pmu.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/powerpc/perf/imc-pmu.c b/arch/powerpc/perf/imc-pmu.c index 52017f6eafd9..a8f95f96d54b 100644 --- a/arch/powerpc/perf/imc-pmu.c +++ b/arch/powerpc/perf/imc-pmu.c @@ -1064,7 +1064,7 @@ static int init_nest_pmu_ref(void) */ for_each_possible_cpu(cpu) { nid = cpu_to_node(cpu); - for_each_online_node(i) { + for (i = 0; i < num_possible_nodes(); i++) { if (nest_imc_refc[i].id == nid) { per_cpu(local_nest_imc_refc, cpu) = &nest_imc_refc[i]; break; -- GitLab