* [PATCH] perf/rapl: fix sysfs_show() initialization for RAPL PMU
@ 2015-01-13 22:59 Stephane Eranian
2015-01-16 8:42 ` [tip:perf/urgent] perf/rapl: Fix " tip-bot for Stephane Eranian
0 siblings, 1 reply; 2+ messages in thread
From: Stephane Eranian @ 2015-01-13 22:59 UTC (permalink / raw)
To: linux-kernel; +Cc: peterz, mingo, ak, vincent.weaver, jolsa
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>
---
arch/x86/kernel/cpu/perf_event_intel_rapl.c | 44 +++++++++++++++++++++--------
1 file 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),
--
1.9.1
^ permalink raw reply related [flat|nested] 2+ messages in thread
* [tip:perf/urgent] perf/rapl: Fix sysfs_show() initialization for RAPL PMU
2015-01-13 22:59 [PATCH] perf/rapl: fix sysfs_show() initialization for RAPL PMU Stephane Eranian
@ 2015-01-16 8:42 ` tip-bot for Stephane Eranian
0 siblings, 0 replies; 2+ messages in thread
From: tip-bot for Stephane Eranian @ 2015-01-16 8:42 UTC (permalink / raw)
To: linux-tip-commits
Cc: eranian, torvalds, acme, tglx, linux-kernel, peterz, hpa, mingo
Commit-ID: 433678bdc6ed39f053c55da96b51de5bf0aeebb1
Gitweb: http://git.kernel.org/tip/433678bdc6ed39f053c55da96b51de5bf0aeebb1
Author: Stephane Eranian <eranian@google.com>
AuthorDate: Tue, 13 Jan 2015 23:59:53 +0100
Committer: Ingo Molnar <mingo@kernel.org>
CommitDate: Fri, 16 Jan 2015 09:06:58 +0100
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>
---
arch/x86/kernel/cpu/perf_event_intel_rapl.c | 44 +++++++++++++++++++++--------
1 file 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),
^ permalink raw reply related [flat|nested] 2+ messages in thread
end of thread, other threads:[~2015-01-16 8:43 UTC | newest]
Thread overview: 2+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2015-01-13 22:59 [PATCH] perf/rapl: fix sysfs_show() initialization for RAPL PMU Stephane Eranian
2015-01-16 8:42 ` [tip:perf/urgent] perf/rapl: Fix " tip-bot for Stephane Eranian
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).