Messages in this thread | | | From | Ganapatrao Kulkarni <> | Date | Thu, 20 Apr 2017 14:56:50 +0530 | Subject | Re: [PATCH v2] arm64: perf: Use only exclude_kernel attribute when kernel is running in HYP |
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On Thu, Apr 20, 2017 at 2:19 PM, Mark Rutland <mark.rutland@arm.com> wrote: > On Wed, Apr 19, 2017 at 11:14:06PM +0530, Ganapatrao Kulkarni wrote: >> commit d98ecda (arm64: perf: Count EL2 events if the kernel is running in HYP) >> is returning error for perf syscall with mixed attribute set for exclude_kernel >> and exclude_hv. This change is breaking some applications (observed with hhvm) >> when ran on VHE enabled platforms. >> >> Adding fix to consider only exclude_kernel attribute when kernel is >> running in HYP. Also adding sysfs file to notify the bhehaviour >> of attribute exclude_hv. >> >> Signed-off-by: Ganapatrao Kulkarni <ganapatrao.kulkarni@cavium.com> >> --- >> >> Changelog: >> >> V2: >> - Changes as per Will Deacon's suggestion. >> >> V1: Initial patch >> >> arch/arm64/kernel/perf_event.c | 28 ++++++++++++++++++++++++---- >> include/linux/perf/arm_pmu.h | 1 + >> 2 files changed, 25 insertions(+), 4 deletions(-) >> >> @@ -871,14 +890,13 @@ static int armv8pmu_set_event_filter(struct hw_perf_event *event, >> >> if (attr->exclude_idle) >> return -EPERM; >> - if (is_kernel_in_hyp_mode() && >> - attr->exclude_kernel != attr->exclude_hv) >> - return -EINVAL; >> + if (is_kernel_in_hyp_mode() && !attr->exclude_kernel) >> + config_base |= ARMV8_PMU_INCLUDE_EL2; >> if (attr->exclude_user) >> config_base |= ARMV8_PMU_EXCLUDE_EL0; >> if (!is_kernel_in_hyp_mode() && attr->exclude_kernel) >> config_base |= ARMV8_PMU_EXCLUDE_EL1; >> - if (!attr->exclude_hv) >> + if (!is_kernel_in_hyp_mode() && !attr->exclude_hv) >> config_base |= ARMV8_PMU_INCLUDE_EL2; > > This isn't quite what Will suggested. > > The idea was that userspace would read sysfs, then use that to determine > the correct exclusion parameters [1,2]. This logic was not expected to > change; it correctly validates whether we can provide what the user > requests.
OK, if you are ok with sysfs part, i can send next version with that change only?.
> > Thanks, > Mark. > > [1] http://lists.infradead.org/pipermail/linux-arm-kernel/2017-April/499224.html > [2] http://lists.infradead.org/pipermail/linux-arm-kernel/2017-April/499493.html > >> >> /* >> @@ -1008,6 +1026,8 @@ static int armv8_pmuv3_init(struct arm_pmu *cpu_pmu) >> &armv8_pmuv3_events_attr_group; >> cpu_pmu->attr_groups[ARMPMU_ATTR_GROUP_FORMATS] = >> &armv8_pmuv3_format_attr_group; >> + cpu_pmu->attr_groups[ARMPMU_ATTR_GROUP_ATTR] = >> + &armv8_pmuv3_attr_group; >> return armv8pmu_probe_pmu(cpu_pmu); >> } >> >> diff --git a/include/linux/perf/arm_pmu.h b/include/linux/perf/arm_pmu.h >> index 8462da2..a26ffc7 100644 >> --- a/include/linux/perf/arm_pmu.h >> +++ b/include/linux/perf/arm_pmu.h >> @@ -81,6 +81,7 @@ enum armpmu_attr_groups { >> ARMPMU_ATTR_GROUP_COMMON, >> ARMPMU_ATTR_GROUP_EVENTS, >> ARMPMU_ATTR_GROUP_FORMATS, >> + ARMPMU_ATTR_GROUP_ATTR, >> ARMPMU_NR_ATTR_GROUPS >> }; >> >> -- >> 1.8.1.4 >>
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