In some cases, when probing a perf MSR, we're probing certain bits of the
MSR instead of the whole register, thus only these bits should be checked.
For example, for RAPL ENERGY_STATUS MSR, only the lower 32 bits represents
the energy counter, and the higher 32bits are reserved.
Introduce a new mask field in struct perf_msr to allow probing certain
bits of a MSR.
This change is transparent to the current perf_msr_probe() users.
Signed-off-by: Zhang Rui <[email protected]>
Reviewed-by: Andi Kleen <[email protected]>
---
arch/x86/events/probe.c | 5 ++++-
arch/x86/events/probe.h | 7 ++++---
2 files changed, 8 insertions(+), 4 deletions(-)
diff --git a/arch/x86/events/probe.c b/arch/x86/events/probe.c
index 136a1e847254..a0a19c404cb5 100644
--- a/arch/x86/events/probe.c
+++ b/arch/x86/events/probe.c
@@ -28,6 +28,7 @@ perf_msr_probe(struct perf_msr *msr, int cnt, bool zero, void *data)
for (bit = 0; bit < cnt; bit++) {
if (!msr[bit].no_check) {
struct attribute_group *grp = msr[bit].grp;
+ u64 mask;
/* skip entry with no group */
if (!grp)
@@ -44,8 +45,10 @@ perf_msr_probe(struct perf_msr *msr, int cnt, bool zero, void *data)
/* Virt sucks; you cannot tell if a R/O MSR is present :/ */
if (rdmsrl_safe(msr[bit].msr, &val))
continue;
+
+ mask = msr[bit].mask ? msr[bit].mask : U64_MAX;
/* Disable zero counters if requested. */
- if (!zero && !val)
+ if (!zero && !(val & mask))
continue;
grp->is_visible = NULL;
diff --git a/arch/x86/events/probe.h b/arch/x86/events/probe.h
index 4c8e0afc5fb5..261b9bda24e3 100644
--- a/arch/x86/events/probe.h
+++ b/arch/x86/events/probe.h
@@ -4,10 +4,11 @@
#include <linux/sysfs.h>
struct perf_msr {
- u64 msr;
- struct attribute_group *grp;
+ u64 msr;
+ struct attribute_group *grp;
bool (*test)(int idx, void *data);
- bool no_check;
+ bool no_check;
+ u64 mask;
};
unsigned long
--
2.17.1
The following commit has been merged into the perf/core branch of tip:
Commit-ID: ffb20c2e52e8709b5fc9951e8863e31efb1f2cba
Gitweb: https://git.kernel.org/tip/ffb20c2e52e8709b5fc9951e8863e31efb1f2cba
Author: Zhang Rui <[email protected]>
AuthorDate: Fri, 05 Feb 2021 00:18:14 +08:00
Committer: Peter Zijlstra <[email protected]>
CommitterDate: Wed, 10 Feb 2021 14:44:54 +01:00
perf/x86/rapl: Add msr mask support
In some cases, when probing a perf MSR, we're probing certain bits of the
MSR instead of the whole register, thus only these bits should be checked.
For example, for RAPL ENERGY_STATUS MSR, only the lower 32 bits represents
the energy counter, and the higher 32bits are reserved.
Introduce a new mask field in struct perf_msr to allow probing certain
bits of a MSR.
This change is transparent to the current perf_msr_probe() users.
Signed-off-by: Zhang Rui <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Reviewed-by: Andi Kleen <[email protected]>
Link: https://lkml.kernel.org/r/[email protected]
---
arch/x86/events/probe.c | 7 ++++++-
arch/x86/events/probe.h | 7 ++++---
2 files changed, 10 insertions(+), 4 deletions(-)
diff --git a/arch/x86/events/probe.c b/arch/x86/events/probe.c
index 136a1e8..600bf8d 100644
--- a/arch/x86/events/probe.c
+++ b/arch/x86/events/probe.c
@@ -28,6 +28,7 @@ perf_msr_probe(struct perf_msr *msr, int cnt, bool zero, void *data)
for (bit = 0; bit < cnt; bit++) {
if (!msr[bit].no_check) {
struct attribute_group *grp = msr[bit].grp;
+ u64 mask;
/* skip entry with no group */
if (!grp)
@@ -44,8 +45,12 @@ perf_msr_probe(struct perf_msr *msr, int cnt, bool zero, void *data)
/* Virt sucks; you cannot tell if a R/O MSR is present :/ */
if (rdmsrl_safe(msr[bit].msr, &val))
continue;
+
+ mask = msr[bit].mask;
+ if (!mask)
+ mask = ~0ULL;
/* Disable zero counters if requested. */
- if (!zero && !val)
+ if (!zero && !(val & mask))
continue;
grp->is_visible = NULL;
diff --git a/arch/x86/events/probe.h b/arch/x86/events/probe.h
index 4c8e0af..261b9bd 100644
--- a/arch/x86/events/probe.h
+++ b/arch/x86/events/probe.h
@@ -4,10 +4,11 @@
#include <linux/sysfs.h>
struct perf_msr {
- u64 msr;
- struct attribute_group *grp;
+ u64 msr;
+ struct attribute_group *grp;
bool (*test)(int idx, void *data);
- bool no_check;
+ bool no_check;
+ u64 mask;
};
unsigned long