diff options
author | Ravi Bangoria <ravi.bangoria@amd.com> | 2023-05-04 14:00:01 +0300 |
---|---|---|
committer | Peter Zijlstra <peterz@infradead.org> | 2023-05-08 11:58:30 +0300 |
commit | 2fad201fe38ff9a692acedb1990ece2c52a29f95 (patch) | |
tree | ca8658cef7f05658640c17cdd9a3e2017ba27ad4 /arch/x86/include/asm/perf_event.h | |
parent | 0d6d062ca27ec7ef547712d34dcfcfb952bcef53 (diff) | |
download | linux-2fad201fe38ff9a692acedb1990ece2c52a29f95.tar.xz |
perf/ibs: Fix interface via core pmu events
Although, IBS pmus can be invoked via their own interface, indirect
IBS invocation via core pmu events is also supported with fixed set
of events: cpu-cycles:p, r076:p (same as cpu-cycles:p) and r0C1:p
(micro-ops) for user convenience.
This indirect IBS invocation is broken since commit 66d258c5b048
("perf/core: Optimize perf_init_event()"), which added RAW pmu under
'pmu_idr' list and thus if event_init() fails with RAW pmu, it started
returning error instead of trying other pmus.
Forward precise events from core pmu to IBS by overwriting 'type' and
'config' in the kernel copy of perf_event_attr. Overwriting will cause
perf_init_event() to retry with updated 'type' and 'config', which will
automatically forward event to IBS pmu.
Without patch:
$ sudo ./perf record -C 0 -e r076:p -- sleep 1
Error:
The r076:p event is not supported.
With patch:
$ sudo ./perf record -C 0 -e r076:p -- sleep 1
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.341 MB perf.data (37 samples) ]
Fixes: 66d258c5b048 ("perf/core: Optimize perf_init_event()")
Reported-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Ravi Bangoria <ravi.bangoria@amd.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20230504110003.2548-3-ravi.bangoria@amd.com
Diffstat (limited to 'arch/x86/include/asm/perf_event.h')
-rw-r--r-- | arch/x86/include/asm/perf_event.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/x86/include/asm/perf_event.h b/arch/x86/include/asm/perf_event.h index 8fc15ed5e60b..fc86248215e2 100644 --- a/arch/x86/include/asm/perf_event.h +++ b/arch/x86/include/asm/perf_event.h @@ -475,8 +475,10 @@ struct pebs_xmm { #ifdef CONFIG_X86_LOCAL_APIC extern u32 get_ibs_caps(void); +extern int forward_event_to_ibs(struct perf_event *event); #else static inline u32 get_ibs_caps(void) { return 0; } +static inline int forward_event_to_ibs(struct perf_event *event) { return -ENOENT; } #endif #ifdef CONFIG_PERF_EVENTS |