diff options
author | Namhyung Kim <[email protected]> | 2023-04-27 16:48:33 -0700 |
---|---|---|
committer | Arnaldo Carvalho de Melo <[email protected]> | 2023-05-02 08:36:14 -0300 |
commit | b9f82b5c63bf5390da19e879275a792a959a8dac (patch) | |
tree | 3c7f3c5c239da5f859eaf798ba504e899a734f82 | |
parent | e53de7b65a3ca59af268c78df2d773f277f717fd (diff) |
perf lock contention: Rework offset calculation with BPF CO-RE
It seems BPF CO-RE reloc doesn't work well with the pattern that gets
the field-offset only. Use offsetof() to make it explicit so that
the compiler would generate the correct code.
Fixes: 0c1228486befa3d6 ("perf lock contention: Support pre-5.14 kernels")
Signed-off-by: Namhyung Kim <[email protected]>
Acked-by: Ian Rogers <[email protected]>
Cc: Adrian Hunter <[email protected]>
Cc: Andrii Nakryiko <[email protected]>
Cc: Hao Luo <[email protected]>
Cc: Ian Rogers <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Song Liu <[email protected]>
Cc: [email protected]
Co-developed-by: Andrii Nakryiko <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
-rw-r--r-- | tools/perf/util/bpf_skel/lock_contention.bpf.c | 14 |
1 files changed, 7 insertions, 7 deletions
diff --git a/tools/perf/util/bpf_skel/lock_contention.bpf.c b/tools/perf/util/bpf_skel/lock_contention.bpf.c index 30c193078bdb..8d3cfbb3cc65 100644 --- a/tools/perf/util/bpf_skel/lock_contention.bpf.c +++ b/tools/perf/util/bpf_skel/lock_contention.bpf.c @@ -429,21 +429,21 @@ struct rq___new { SEC("raw_tp/bpf_test_finish") int BPF_PROG(collect_lock_syms) { - __u64 lock_addr; + __u64 lock_addr, lock_off; __u32 lock_flag; + if (bpf_core_field_exists(struct rq___new, __lock)) + lock_off = offsetof(struct rq___new, __lock); + else + lock_off = offsetof(struct rq___old, lock); + for (int i = 0; i < MAX_CPUS; i++) { struct rq *rq = bpf_per_cpu_ptr(&runqueues, i); - struct rq___new *rq_new = (void *)rq; - struct rq___old *rq_old = (void *)rq; if (rq == NULL) break; - if (bpf_core_field_exists(rq_new->__lock)) - lock_addr = (__u64)&rq_new->__lock; - else - lock_addr = (__u64)&rq_old->lock; + lock_addr = (__u64)(void *)rq + lock_off; lock_flag = LOCK_CLASS_RQLOCK; bpf_map_update_elem(&lock_syms, &lock_addr, &lock_flag, BPF_ANY); } |