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authorAdrian Hunter <adrian.hunter@intel.com>2021-09-07 19:39:01 +0300
committerPeter Zijlstra <peterz@infradead.org>2021-10-15 12:25:31 +0300
commit8b8ff8cc3b8155c18162e8b1f70e1230db176862 (patch)
tree7fa6284dbe477808c4a93170cfb6ea7ac5463980 /kernel/events
parent41100833cdd8b1bef363b81a6482d74711c116ad (diff)
downloadlinux-8b8ff8cc3b8155c18162e8b1f70e1230db176862.tar.xz
perf/x86: Add new event for AUX output counter index
PEBS-via-PT records contain a mask of applicable counters. To identify which event belongs to which counter, a side-band event is needed. Until now, there has been no side-band event, and consequently users were limited to using a single event. Add such a side-band event. Note the event is optimised to output only when the counter index changes for an event. That works only so long as all PEBS-via-PT events are scheduled together, which they are for a recording session because they are in a single group. Also no attribute bit is used to select the new event, so a new kernel is not compatible with older perf tools. The assumption being that PEBS-via-PT is sufficiently esoteric that users will not be troubled by this. Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20210907163903.11820-2-adrian.hunter@intel.com
Diffstat (limited to 'kernel/events')
-rw-r--r--kernel/events/core.c30
1 files changed, 30 insertions, 0 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 1cb1f9b8392e..0e90a5084f18 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -9062,6 +9062,36 @@ static void perf_log_itrace_start(struct perf_event *event)
perf_output_end(&handle);
}
+void perf_report_aux_output_id(struct perf_event *event, u64 hw_id)
+{
+ struct perf_output_handle handle;
+ struct perf_sample_data sample;
+ struct perf_aux_event {
+ struct perf_event_header header;
+ u64 hw_id;
+ } rec;
+ int ret;
+
+ if (event->parent)
+ event = event->parent;
+
+ rec.header.type = PERF_RECORD_AUX_OUTPUT_HW_ID;
+ rec.header.misc = 0;
+ rec.header.size = sizeof(rec);
+ rec.hw_id = hw_id;
+
+ perf_event_header__init_id(&rec.header, &sample, event);
+ ret = perf_output_begin(&handle, &sample, event, rec.header.size);
+
+ if (ret)
+ return;
+
+ perf_output_put(&handle, rec);
+ perf_event__output_id_sample(event, &handle, &sample);
+
+ perf_output_end(&handle);
+}
+
static int
__perf_event_account_interrupt(struct perf_event *event, int throttle)
{