| Message ID | 20231010054617.1901616-2-namhyung@kernel.org (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | BPF |
| Headers | show |
| Series | [v2,1/2] perf lock contention: Clear lock addr after use | expand |
| Context | Check | Description |
|---|---|---|
| netdev/tree_selection | success | Not a local patch |
diff --git a/tools/perf/util/bpf_skel/lock_contention.bpf.c b/tools/perf/util/bpf_skel/lock_contention.bpf.c index b11179452e19..69d31fd77cd0 100644 --- a/tools/perf/util/bpf_skel/lock_contention.bpf.c +++ b/tools/perf/util/bpf_skel/lock_contention.bpf.c @@ -328,7 +328,11 @@ int contention_begin(u64 *ctx) if (pelem == NULL) { struct tstamp_data zero = {}; - bpf_map_update_elem(&tstamp, &pid, &zero, BPF_ANY); + if (bpf_map_update_elem(&tstamp, &pid, &zero, BPF_NOEXIST) < 0) { + __sync_fetch_and_add(&task_fail, 1); + return 0; + } + pelem = bpf_map_lookup_elem(&tstamp, &pid); if (pelem == NULL) { __sync_fetch_and_add(&task_fail, 1);
To be more conservative, let's check the return value of bpf_map_update_elem() for the tstamp map for a task and change the flag to BPF_NOEXIST so that it cannot update any existing element. Signed-off-by: Namhyung Kim <namhyung@kernel.org> --- tools/perf/util/bpf_skel/lock_contention.bpf.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)