Add stats to observe the success and failure rate of lock acquisition attempts in various contexts. Signed-off-by: Kumar Kartikeya Dwivedi --- .../bpf/test_kmods/bpf_test_rqspinlock.c | 55 +++++++++++++++---- 1 file changed, 43 insertions(+), 12 deletions(-) diff --git a/tools/testing/selftests/bpf/test_kmods/bpf_test_rqspinlock.c b/tools/testing/selftests/bpf/test_kmods/bpf_test_rqspinlock.c index e8dd3fbc6ea5..7b4ae5e81d32 100644 --- a/tools/testing/selftests/bpf/test_kmods/bpf_test_rqspinlock.c +++ b/tools/testing/selftests/bpf/test_kmods/bpf_test_rqspinlock.c @@ -33,9 +33,16 @@ static const unsigned int rqsl_hist_ms[] = { }; #define RQSL_NR_HIST_BUCKETS ARRAY_SIZE(rqsl_hist_ms) +enum rqsl_context { + RQSL_CTX_NORMAL = 0, + RQSL_CTX_NMI, + RQSL_CTX_MAX, +}; + struct rqsl_cpu_hist { - atomic64_t normal[RQSL_NR_HIST_BUCKETS]; - atomic64_t nmi[RQSL_NR_HIST_BUCKETS]; + atomic64_t hist[RQSL_CTX_MAX][RQSL_NR_HIST_BUCKETS]; + atomic64_t success[RQSL_CTX_MAX]; + atomic64_t failure[RQSL_CTX_MAX]; }; static DEFINE_PER_CPU(struct rqsl_cpu_hist, rqsl_cpu_hists); @@ -117,14 +124,18 @@ static u32 rqsl_hist_bucket_idx(u32 delta_ms) return RQSL_NR_HIST_BUCKETS - 1; } -static void rqsl_record_lock_time(u64 delta_ns, bool is_nmi) +static void rqsl_record_lock_result(u64 delta_ns, enum rqsl_context ctx, int ret) { struct rqsl_cpu_hist *hist = this_cpu_ptr(&rqsl_cpu_hists); u32 delta_ms = DIV_ROUND_UP_ULL(delta_ns, NSEC_PER_MSEC); u32 bucket = rqsl_hist_bucket_idx(delta_ms); - atomic64_t *buckets = is_nmi ? hist->nmi : hist->normal; + atomic64_t *buckets = hist->hist[ctx]; atomic64_inc(&buckets[bucket]); + if (!ret) + atomic64_inc(&hist->success[ctx]); + else + atomic64_inc(&hist->failure[ctx]); } static int rqspinlock_worker_fn(void *arg) @@ -147,7 +158,8 @@ static int rqspinlock_worker_fn(void *arg) } start_ns = ktime_get_mono_fast_ns(); ret = raw_res_spin_lock_irqsave(worker_lock, flags); - rqsl_record_lock_time(ktime_get_mono_fast_ns() - start_ns, false); + rqsl_record_lock_result(ktime_get_mono_fast_ns() - start_ns, + RQSL_CTX_NORMAL, ret); mdelay(normal_delay); if (!ret) raw_res_spin_unlock_irqrestore(worker_lock, flags); @@ -190,7 +202,8 @@ static void nmi_cb(struct perf_event *event, struct perf_sample_data *data, locks = rqsl_get_lock_pair(cpu); start_ns = ktime_get_mono_fast_ns(); ret = raw_res_spin_lock_irqsave(locks.nmi_lock, flags); - rqsl_record_lock_time(ktime_get_mono_fast_ns() - start_ns, true); + rqsl_record_lock_result(ktime_get_mono_fast_ns() - start_ns, + RQSL_CTX_NMI, ret); mdelay(nmi_delay); @@ -300,12 +313,14 @@ static void rqsl_print_histograms(void) u64 norm_counts[RQSL_NR_HIST_BUCKETS]; u64 nmi_counts[RQSL_NR_HIST_BUCKETS]; u64 total_counts[RQSL_NR_HIST_BUCKETS]; + u64 norm_success, nmi_success, success_total; + u64 norm_failure, nmi_failure, failure_total; u64 norm_total = 0, nmi_total = 0, total = 0; bool has_slow = false; for (i = 0; i < RQSL_NR_HIST_BUCKETS; i++) { - norm_counts[i] = atomic64_read(&hist->normal[i]); - nmi_counts[i] = atomic64_read(&hist->nmi[i]); + norm_counts[i] = atomic64_read(&hist->hist[RQSL_CTX_NORMAL][i]); + nmi_counts[i] = atomic64_read(&hist->hist[RQSL_CTX_NMI][i]); total_counts[i] = norm_counts[i] + nmi_counts[i]; norm_total += norm_counts[i]; nmi_total += nmi_counts[i]; @@ -315,17 +330,33 @@ static void rqsl_print_histograms(void) has_slow = true; } + norm_success = atomic64_read(&hist->success[RQSL_CTX_NORMAL]); + nmi_success = atomic64_read(&hist->success[RQSL_CTX_NMI]); + norm_failure = atomic64_read(&hist->failure[RQSL_CTX_NORMAL]); + nmi_failure = atomic64_read(&hist->failure[RQSL_CTX_NMI]); + success_total = norm_success + nmi_success; + failure_total = norm_failure + nmi_failure; + if (!total) continue; if (!has_slow) { - pr_err(" cpu%d: total %llu (normal %llu, nmi %llu), all within 0-%ums\n", - cpu, total, norm_total, nmi_total, RQSL_SLOW_THRESHOLD_MS); + pr_err(" cpu%d: total %llu (normal %llu, nmi %llu) | " + "success %llu (normal %llu, nmi %llu) | " + "failure %llu (normal %llu, nmi %llu), all within 0-%ums\n", + cpu, total, norm_total, nmi_total, + success_total, norm_success, nmi_success, + failure_total, norm_failure, nmi_failure, + RQSL_SLOW_THRESHOLD_MS); continue; } - pr_err(" cpu%d: total %llu (normal %llu, nmi %llu)\n", - cpu, total, norm_total, nmi_total); + pr_err(" cpu%d: total %llu (normal %llu, nmi %llu) | " + "success %llu (normal %llu, nmi %llu) | " + "failure %llu (normal %llu, nmi %llu)\n", + cpu, total, norm_total, nmi_total, + success_total, norm_success, nmi_success, + failure_total, norm_failure, nmi_failure); for (i = 0; i < RQSL_NR_HIST_BUCKETS; i++) { unsigned int start_ms; -- 2.51.0