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perf/core: Save raw sample data conditionally based on sample type

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BugLink: https://bugs.launchpad.net/bugs/2111953

[ Upstream commit b9c44b91476b67327a521568a854babecc4070ab ]

Currently, space for raw sample data is always allocated within sample
records for both BPF output and tracepoint events. This leads to unused
space in sample records when raw sample data is not requested.

This patch enforces checking sample type of an event in
perf_sample_save_raw_data(). So raw sample data will only be saved if
explicitly requested, reducing overhead when it is not needed.

Fixes: 0a9081cf0a ("perf/core: Add perf_sample_save_raw_data() helper")
Signed-off-by: Yabin Cui <yabinc@google.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Ian Rogers <irogers@google.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20240515193610.2350456-2-yabinc@google.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Manuel Diewald <manuel.diewald@canonical.com>
Signed-off-by: Mehmet Basaran <mehmet.basaran@canonical.com>
This commit is contained in:
Yabin Cui
2024-05-15 12:36:07 -07:00
committed by Mehmet Basaran
parent 0278422474
commit dc1c098b1a
7 changed files with 34 additions and 26 deletions
Download Patch File Download Diff File Expand all files Collapse all files
kernel/trace/bpf_trace.c
+6 -5
View File
@@ -620,7 +620,8 @@ static const struct bpf_func_proto bpf_perf_event_read_value_proto = {
static __always_inline u64
__bpf_perf_event_output(struct pt_regs *regs, struct bpf_map *map,
u64 flags, struct perf_sample_data *sd)
u64 flags, struct perf_raw_record *raw,
struct perf_sample_data *sd)
{
struct bpf_array *array = container_of(map, struct bpf_array, map);
unsigned int cpu = smp_processor_id();
@@ -645,6 +646,8 @@ __bpf_perf_event_output(struct pt_regs *regs, struct bpf_map *map,
if (unlikely(event->oncpu != cpu))
return -EOPNOTSUPP;
perf_sample_save_raw_data(sd, event, raw);
return perf_event_output(event, sd, regs);
}
@@ -688,9 +691,8 @@ BPF_CALL_5(bpf_perf_event_output, struct pt_regs *, regs, struct bpf_map *, map,
}
perf_sample_data_init(sd, 0, 0);
perf_sample_save_raw_data(sd, &raw);
err = __bpf_perf_event_output(regs, map, flags, sd);
err = __bpf_perf_event_output(regs, map, flags, &raw, sd);
out:
this_cpu_dec(bpf_trace_nest_level);
preempt_enable();
@@ -749,9 +751,8 @@ u64 bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size,
perf_fetch_caller_regs(regs);
perf_sample_data_init(sd, 0, 0);
perf_sample_save_raw_data(sd, &raw);
ret = __bpf_perf_event_output(regs, map, flags, sd);
ret = __bpf_perf_event_output(regs, map, flags, &raw, sd);
out:
this_cpu_dec(bpf_event_output_nest_level);
preempt_enable();