Messages in this thread | | | Subject | Re: [RFC V1 10/11] perf: Expand perf_branch_entry.type | From | Anshuman Khandual <> | Date | Fri, 28 Jan 2022 09:44:22 +0530 |
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On 1/25/22 10:28 PM, James Clark wrote: > > On 24/01/2022 04:30, Anshuman Khandual wrote: >> Current perf_branch_entry.type is a 4 bits field just enough to accommodate >> 16 generic branch types. This is insufficient to accommodate platforms like >> arm64 which has much more branch types. Lets just expands this field into a >> 6 bits one, which can now hold 64 generic branch types. This also adds more >> generic branch types and updates the BRBE driver as required. >> >> Cc: Peter Zijlstra <peterz@infradead.org> >> Cc: Ingo Molnar <mingo@redhat.com> >> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> >> Cc: Mark Rutland <mark.rutland@arm.com> >> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> >> Cc: Jiri Olsa <jolsa@redhat.com> >> Cc: Namhyung Kim <namhyung@kernel.org> >> Cc: Will Deacon <will@kernel.org> >> Cc: linux-arm-kernel@lists.infradead.org >> Cc: linux-perf-users@vger.kernel.org >> Cc: linux-kernel@vger.kernel.org >> Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com> >> --- >> drivers/perf/arm_pmu_brbe.c | 7 ++++++- >> include/uapi/linux/perf_event.h | 10 ++++++++-- >> tools/include/uapi/linux/perf_event.h | 10 ++++++++-- >> tools/perf/util/branch.c | 8 +++++++- >> 4 files changed, 29 insertions(+), 6 deletions(-) >> >> diff --git a/drivers/perf/arm_pmu_brbe.c b/drivers/perf/arm_pmu_brbe.c >> index 8d27ad868359..7cd1208c6c58 100644 >> --- a/drivers/perf/arm_pmu_brbe.c >> +++ b/drivers/perf/arm_pmu_brbe.c >> @@ -253,12 +253,17 @@ static int brbe_fetch_perf_type(u64 brbinf) >> case BRBINF_TYPE_DEBUG_EXIT: >> return PERF_BR_DEBUG_EXIT; >> case BRBINF_TYPE_SERROR: >> + return PERF_BR_SERROR; >> case BRBINF_TYPE_INST_DEBUG: >> + return PERF_BR_DEBUG_INST; >> case BRBINF_TYPE_DATA_DEBUG: >> + return PERF_BR_DEBUG_DATA; >> case BRBINF_TYPE_ALGN_FAULT: >> + return PERF_BR_FAULT_ALGN; >> case BRBINF_TYPE_INST_FAULT: >> + return PERF_BR_FAULT_INST; >> case BRBINF_TYPE_DATA_FAULT: >> - return PERF_BR_UNKNOWN; >> + return PERF_BR_FAULT_DATA; >> default: >> pr_warn("unknown branch type captured\n"); >> return PERF_BR_UNKNOWN; >> diff --git a/include/uapi/linux/perf_event.h b/include/uapi/linux/perf_event.h >> index b91d0f575d0c..361fdc6b87a0 100644 >> --- a/include/uapi/linux/perf_event.h >> +++ b/include/uapi/linux/perf_event.h >> @@ -256,6 +256,12 @@ enum { >> PERF_BR_FIQ = 13, /* fiq */ >> PERF_BR_DEBUG_HALT = 14, /* debug halt */ >> PERF_BR_DEBUG_EXIT = 15, /* debug exit */ >> + PERF_BR_DEBUG_INST = 16, /* instruciton debug */ >> + PERF_BR_DEBUG_DATA = 17, /* data debug */ >> + PERF_BR_FAULT_ALGN = 18, /* alignment fault */ >> + PERF_BR_FAULT_DATA = 19, /* data fault */ >> + PERF_BR_FAULT_INST = 20, /* instruction fault */ >> + PERF_BR_SERROR = 21, /* system error */ >> PERF_BR_MAX, >> }; >> >> @@ -1370,8 +1376,8 @@ struct perf_branch_entry { >> in_tx:1, /* in transaction */ >> abort:1, /* transaction abort */ >> cycles:16, /* cycle count to last branch */ >> - type:4, /* branch type */ >> - reserved:40; >> + type:6, /* branch type */ >> + reserved:38; >> }; >> >> union perf_sample_weight { >> diff --git a/tools/include/uapi/linux/perf_event.h b/tools/include/uapi/linux/perf_event.h >> index 1882054e8684..9a82b8aaed93 100644 >> --- a/tools/include/uapi/linux/perf_event.h >> +++ b/tools/include/uapi/linux/perf_event.h >> @@ -256,6 +256,12 @@ enum { >> PERF_BR_FIQ = 13, /* fiq */ >> PERF_BR_DEBUG_HALT = 14, /* debug halt */ >> PERF_BR_DEBUG_EXIT = 15, /* debug exit */ >> + PERF_BR_DEBUG_INST = 16, /* instruciton debug */ >> + PERF_BR_DEBUG_DATA = 17, /* data debug */ >> + PERF_BR_FAULT_ALGN = 18, /* alignment fault */ >> + PERF_BR_FAULT_DATA = 19, /* data fault */ >> + PERF_BR_FAULT_INST = 20, /* instruction fault */ >> + PERF_BR_SERROR = 21, /* system error */ >> PERF_BR_MAX, >> }; >> >> @@ -1370,8 +1376,8 @@ struct perf_branch_entry { >> in_tx:1, /* in transaction */ >> abort:1, /* transaction abort */ >> cycles:16, /* cycle count to last branch */ >> - type:4, /* branch type */ >> - reserved:40; >> + type:6, /* branch type */ >> + reserved:38; >> }; > There's another copy of this struct in branch.h that is used to access the same data in > perf which also needs updating: > > struct branch_flags { > union { > u64 value; > struct { > u64 mispred:1; > u64 predicted:1; > u64 in_tx:1; > u64 abort:1; > u64 cycles:16; > u64 type:4; > u64 reserved:40; > }; > }; > };
Sure, thanks for the catch. Will fix it.
> > It's never assigned directly but there is some casting stuff going on in > evsel__parse_sample() and it eventually ends up being used to access branch > records. Same applies to the privilege data change. >
Okay, will do the necessary changes in the privilege data patch.
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