[PATCH 08/11] arm64: pmu: Provide cpumask attribute for PMU
From: mark.rutland@arm.com (Mark Rutland)
Date: 2016-07-07 16:21:04
Also in:
linux-acpi
Hi Jeremy, Apologies for the late reply on this. On Tue, Jun 21, 2016 at 12:11:46PM -0500, Jeremy Linton wrote:
With heterogeneous PMUs its helpful to know which PMUs are bound to each CPU. Provide that information with a cpumask sysfs entry similar to other PMUs.
Have you tested trying to stat on a particular PMU? e.g. $ perf stat -e armv8_cortex_a53/cpu_cycles/ ls I found that the presence of a cpumask file would cause (at least some versions) of perf-stat to hang, and was holding off adding a cpumask until we had a solution to that. See [1,2] for more details on that.
Signed-off-by: Jeremy Linton <redacted> --- arch/arm64/kernel/perf_event.c | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+)
This should be generic across the arm-pmu code, and so should live under drivers/perf/. Thanks, Mark. [1] http://lkml.kernel.org/r/1467907474-3290-1-git-send-email-mark.rutland at arm.com [2] http://lkml.kernel.org/r/1467907474-3290-2-git-send-email-mark.rutland at arm.com
quoted hunk ↗ jump to hunk
diff --git a/arch/arm64/kernel/perf_event.c b/arch/arm64/kernel/perf_event.c index 356fa6c..dae73ea 100644 --- a/arch/arm64/kernel/perf_event.c +++ b/arch/arm64/kernel/perf_event.c@@ -533,6 +533,26 @@ static struct attribute_group armv8_pmuv3_events_attr_group = { PMU_FORMAT_ATTR(event, "config:0-9"); +static ssize_t +cpumask_show(struct device *dev, struct device_attribute *attr, char *page) +{ + struct pmu *pmu = dev_get_drvdata(dev); + struct arm_pmu *cpu_pmu = container_of(pmu, struct arm_pmu, pmu); + + return cpumap_print_to_pagebuf(true, page, &cpu_pmu->supported_cpus); +} +static DEVICE_ATTR_RO(cpumask); + +static struct attribute *armv8_pmuv3_attrs[] = { + &dev_attr_cpumask.attr, + NULL, +}; + +static struct attribute_group armv8_pmuv3_attr_group = { + .attrs = armv8_pmuv3_attrs, +}; + + static struct attribute *armv8_pmuv3_format_attrs[] = { &format_attr_event.attr, NULL,@@ -544,6 +564,7 @@ static struct attribute_group armv8_pmuv3_format_attr_group = { }; static const struct attribute_group *armv8_pmuv3_attr_groups[] = { + &armv8_pmuv3_attr_group, &armv8_pmuv3_events_attr_group, &armv8_pmuv3_format_attr_group, NULL,-- 2.5.5