Messages in this thread Patch in this message | | | Date | Wed, 26 Jan 2022 15:34:45 -0800 | Subject | [PATCH v5 04/13] perf/x86/amd: add branch-brs helper event for Fam19h BRS | From | Stephane Eranian <> |
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This patch adds a pseudo event called branch-brs to help use the FAM Fam19h Branch Sampling feature (BRS). BRS samples taken branches, so it is best used when sampling on a retired taken branch event (0xc4) which is what BRS captures. Instead of trying to remember the event code or actual event name, users can simply do:
$ perf record -b -e cpu/branch-brs/ -c 1000037 .....
Signed-off-by: Stephane Eranian <eranian@google.com> --- arch/x86/events/amd/core.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+)
diff --git a/arch/x86/events/amd/core.c b/arch/x86/events/amd/core.c index 44d8f618bb3e..597defee1e02 100644 --- a/arch/x86/events/amd/core.c +++ b/arch/x86/events/amd/core.c @@ -1105,8 +1105,24 @@ static struct attribute_group group_caps_amd_brs = { .is_visible = amd_brs_is_visible, }; +#define AMD_FAM19H_BRS_EVENT 0xc4 /* Fam19h RETIRED_TAKEN_BRANCH_INSTRUCTIONS */ +EVENT_ATTR_STR(branch-brs, amd_branch_brs, + "event=" __stringify(AMD_FAM19H_BRS_EVENT)"\n"); + +static struct attribute *amd_brs_events_attrs[] = { + EVENT_PTR(amd_branch_brs), + NULL, +}; + +static struct attribute_group group_events_amd_brs = { + .name = "events", + .attrs = amd_brs_events_attrs, + .is_visible = amd_brs_is_visible, +}; + static const struct attribute_group *amd_attr_update[] = { &group_caps_amd_brs, + &group_events_amd_brs, NULL, }; -- 2.35.0.rc0.227.g00780c9af4-goog
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