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| author | Namhyung Kim <namhyung@kernel.org> | 2024-08-12 10:25:33 -0700 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2024-08-12 18:04:35 -0300 |
| commit | 040c0f887fdcfe747a3f63c94e9cd29e9ed0b872 (patch) | |
| tree | 32b542de45eb605679a26a4fd4e03eea4b2afeb6 | |
| parent | 00b04242683ebae91164244883b46e6ab2669d63 (diff) | |
| download | linux-040c0f887fdcfe747a3f63c94e9cd29e9ed0b872.tar.gz linux-040c0f887fdcfe747a3f63c94e9cd29e9ed0b872.tar.bz2 linux-040c0f887fdcfe747a3f63c94e9cd29e9ed0b872.zip | |
perf lock contention: Change stack_id type to s32
The bpf_get_stackid() helper returns a signed type to check whether it
failed to get a stacktrace or not. But it saved the result in u32 and
checked if the value is negative.
376 if (needs_callstack) {
377 pelem->stack_id = bpf_get_stackid(ctx, &stacks,
378 BPF_F_FAST_STACK_CMP | stack_skip);
--> 379 if (pelem->stack_id < 0)
./tools/perf/util/bpf_skel/lock_contention.bpf.c:379 contention_begin()
warn: unsigned 'pelem->stack_id' is never less than zero.
Let's change the type to s32 instead.
Fixes: 6d499a6b3d90277d ("perf lock: Print the number of lost entries for BPF")
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20240812172533.2015291-1-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| -rw-r--r-- | tools/perf/util/bpf_skel/lock_data.h | 4 | ||||
| -rw-r--r-- | tools/perf/util/bpf_skel/vmlinux/vmlinux.h | 1 |
2 files changed, 3 insertions, 2 deletions
diff --git a/tools/perf/util/bpf_skel/lock_data.h b/tools/perf/util/bpf_skel/lock_data.h index 36af11faad03..de12892f992f 100644 --- a/tools/perf/util/bpf_skel/lock_data.h +++ b/tools/perf/util/bpf_skel/lock_data.h @@ -7,11 +7,11 @@ struct tstamp_data { u64 timestamp; u64 lock; u32 flags; - u32 stack_id; + s32 stack_id; }; struct contention_key { - u32 stack_id; + s32 stack_id; u32 pid; u64 lock_addr_or_cgroup; }; diff --git a/tools/perf/util/bpf_skel/vmlinux/vmlinux.h b/tools/perf/util/bpf_skel/vmlinux/vmlinux.h index e9028235d771..d818e30c5457 100644 --- a/tools/perf/util/bpf_skel/vmlinux/vmlinux.h +++ b/tools/perf/util/bpf_skel/vmlinux/vmlinux.h @@ -15,6 +15,7 @@ typedef __u8 u8; typedef __u32 u32; +typedef __s32 s32; typedef __u64 u64; typedef __s64 s64; |