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author | Stephane Eranian <eranian@google.com> | 2015-01-13 22:59:53 (GMT) |
---|---|---|
committer | Ingo Molnar <mingo@kernel.org> | 2015-01-16 08:06:58 (GMT) |
commit | 433678bdc6ed39f053c55da96b51de5bf0aeebb1 (patch) | |
tree | 4f8d1cb9a64d8d4f6b8836099c40d666553ba592 | |
parent | f800c25b7a762d445ba1439a2428c8362157eba6 (diff) | |
download | linux-433678bdc6ed39f053c55da96b51de5bf0aeebb1.tar.xz |
perf/rapl: Fix sysfs_show() initialization for RAPL PMU
This patch fixes a problem with the initialization of the
sysfs_show() routine for the RAPL PMU.
The current code was wrongly relying on the EVENT_ATTR_STR()
macro which uses the events_sysfs_show() function in the x86
PMU code. That function itself was relying on the x86_pmu data
structure. Yet RAPL and the core PMU (x86_pmu) have nothing to
do with each other. They should therefore not interact with
each other.
The x86_pmu structure is initialized at boot time based on
the host CPU model. When the host CPU is not supported, the
x86_pmu remains uninitialized and some of the callbacks it
contains are NULL.
The false dependency with x86_pmu could potentially cause crashes
in case the x86_pmu is not initialized while the RAPL PMU is. This
may, for instance, be the case in virtualized environments.
This patch fixes the problem by using a private sysfs_show()
routine for exporting the RAPL PMU events.
Signed-off-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20150113225953.GA21525@thinkpad
Cc: vincent.weaver@maine.edu
Cc: jolsa@redhat.com
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
-rw-r--r-- | arch/x86/kernel/cpu/perf_event_intel_rapl.c | 44 |
1 files changed, 32 insertions, 12 deletions
diff --git a/arch/x86/kernel/cpu/perf_event_intel_rapl.c b/arch/x86/kernel/cpu/perf_event_intel_rapl.c index 673f930..6e434f8 100644 --- a/arch/x86/kernel/cpu/perf_event_intel_rapl.c +++ b/arch/x86/kernel/cpu/perf_event_intel_rapl.c @@ -103,6 +103,13 @@ static struct kobj_attribute format_attr_##_var = \ #define RAPL_CNTR_WIDTH 32 /* 32-bit rapl counters */ +#define RAPL_EVENT_ATTR_STR(_name, v, str) \ +static struct perf_pmu_events_attr event_attr_##v = { \ + .attr = __ATTR(_name, 0444, rapl_sysfs_show, NULL), \ + .id = 0, \ + .event_str = str, \ +}; + struct rapl_pmu { spinlock_t lock; int hw_unit; /* 1/2^hw_unit Joule */ @@ -379,23 +386,36 @@ static struct attribute_group rapl_pmu_attr_group = { .attrs = rapl_pmu_attrs, }; -EVENT_ATTR_STR(energy-cores, rapl_cores, "event=0x01"); -EVENT_ATTR_STR(energy-pkg , rapl_pkg, "event=0x02"); -EVENT_ATTR_STR(energy-ram , rapl_ram, "event=0x03"); -EVENT_ATTR_STR(energy-gpu , rapl_gpu, "event=0x04"); +static ssize_t rapl_sysfs_show(struct device *dev, + struct device_attribute *attr, + char *page) +{ + struct perf_pmu_events_attr *pmu_attr = \ + container_of(attr, struct perf_pmu_events_attr, attr); + + if (pmu_attr->event_str) + return sprintf(page, "%s", pmu_attr->event_str); + + return 0; +} + +RAPL_EVENT_ATTR_STR(energy-cores, rapl_cores, "event=0x01"); +RAPL_EVENT_ATTR_STR(energy-pkg , rapl_pkg, "event=0x02"); +RAPL_EVENT_ATTR_STR(energy-ram , rapl_ram, "event=0x03"); +RAPL_EVENT_ATTR_STR(energy-gpu , rapl_gpu, "event=0x04"); -EVENT_ATTR_STR(energy-cores.unit, rapl_cores_unit, "Joules"); -EVENT_ATTR_STR(energy-pkg.unit , rapl_pkg_unit, "Joules"); -EVENT_ATTR_STR(energy-ram.unit , rapl_ram_unit, "Joules"); -EVENT_ATTR_STR(energy-gpu.unit , rapl_gpu_unit, "Joules"); +RAPL_EVENT_ATTR_STR(energy-cores.unit, rapl_cores_unit, "Joules"); +RAPL_EVENT_ATTR_STR(energy-pkg.unit , rapl_pkg_unit, "Joules"); +RAPL_EVENT_ATTR_STR(energy-ram.unit , rapl_ram_unit, "Joules"); +RAPL_EVENT_ATTR_STR(energy-gpu.unit , rapl_gpu_unit, "Joules"); /* * we compute in 0.23 nJ increments regardless of MSR */ -EVENT_ATTR_STR(energy-cores.scale, rapl_cores_scale, "2.3283064365386962890625e-10"); -EVENT_ATTR_STR(energy-pkg.scale, rapl_pkg_scale, "2.3283064365386962890625e-10"); -EVENT_ATTR_STR(energy-ram.scale, rapl_ram_scale, "2.3283064365386962890625e-10"); -EVENT_ATTR_STR(energy-gpu.scale, rapl_gpu_scale, "2.3283064365386962890625e-10"); +RAPL_EVENT_ATTR_STR(energy-cores.scale, rapl_cores_scale, "2.3283064365386962890625e-10"); +RAPL_EVENT_ATTR_STR(energy-pkg.scale, rapl_pkg_scale, "2.3283064365386962890625e-10"); +RAPL_EVENT_ATTR_STR(energy-ram.scale, rapl_ram_scale, "2.3283064365386962890625e-10"); +RAPL_EVENT_ATTR_STR(energy-gpu.scale, rapl_gpu_scale, "2.3283064365386962890625e-10"); static struct attribute *rapl_events_srv_attr[] = { EVENT_PTR(rapl_cores), |