From 840a8b55effdc9a98b115f84b8bbb6a2f5d05226 Mon Sep 17 00:00:00 2001 From: Matt Redfearn Date: Fri, 20 Apr 2018 11:23:05 +0100 Subject: MIPS: perf: Use correct VPE ID when setting up VPE tracing There are a couple of FIXME's in the perf code which state that cpu_data[event->cpu].vpe_id reports 0 for both CPUs. This is no longer the case, since the vpe_id is used extensively by SMP CPS. VPE local counting gets around this by using smp_processor_id() instead. As it happens this does work correctly to count events on the right VPE, but relies on 2 assumptions: a) Always having 2 VPEs / core. b) The hardware only paying attention to the least significant bit of the PERFCTL.VPEID field. If either of these assumptions change then the incorrect VPEs events will be counted. Fix this by replacing smp_processor_id() with cpu_vpe_id(¤t_cpu_data), in the vpe_id() macro, and pass vpe_id() to M_PERFCTL_VPEID() when setting up PERFCTL.VPEID. The FIXME's can also be removed since they no longer apply. Signed-off-by: Matt Redfearn Cc: Ralf Baechle Cc: Peter Zijlstra Cc: Ingo Molnar Cc: Arnaldo Carvalho de Melo Cc: Alexander Shishkin Cc: Jiri Olsa Cc: Namhyung Kim Cc: Florian Fainelli Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/19137/ Signed-off-by: James Hogan --- arch/mips/kernel/perf_event_mipsxx.c | 12 ++---------- 1 file changed, 2 insertions(+), 10 deletions(-) (limited to 'arch/mips/kernel') diff --git a/arch/mips/kernel/perf_event_mipsxx.c b/arch/mips/kernel/perf_event_mipsxx.c index 458015da7149..11d1b2268fdd 100644 --- a/arch/mips/kernel/perf_event_mipsxx.c +++ b/arch/mips/kernel/perf_event_mipsxx.c @@ -135,12 +135,8 @@ static DEFINE_RWLOCK(pmuint_rwlock); #define vpe_id() (cpu_has_mipsmt_pertccounters ? \ 0 : (smp_processor_id() & MIPS_CPUID_TO_COUNTER_MASK)) #else -/* - * FIXME: For VSMP, vpe_id() is redefined for Perf-events, because - * cpu_data[cpuid].vpe_id reports 0 for _both_ CPUs. - */ #define vpe_id() (cpu_has_mipsmt_pertccounters ? \ - 0 : smp_processor_id()) + 0 : cpu_vpe_id(¤t_cpu_data)) #endif /* Copied from op_model_mipsxx.c */ @@ -1277,11 +1273,7 @@ static void check_and_calc_range(struct perf_event *event, */ hwc->config_base |= M_TC_EN_ALL; } else { - /* - * FIXME: cpu_data[event->cpu].vpe_id reports 0 - * for both CPUs. - */ - hwc->config_base |= M_PERFCTL_VPEID(event->cpu); + hwc->config_base |= M_PERFCTL_VPEID(vpe_id()); hwc->config_base |= M_TC_EN_VPE; } } else -- cgit v1.2.3