Commit 3448375e authored by Kumar Kartikeya Dwivedi's avatar Kumar Kartikeya Dwivedi Committed by Alexei Starovoitov
Browse files

selftests/bpf: Add success stats to rqspinlock stress test 



Add stats to observe the success and failure rate of lock acquisition
attempts in various contexts.

Signed-off-by: default avatarKumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20251128232802.1031906-7-memxor@gmail.com


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent 087849cc

tools/testing/selftests/bpf/test_kmods/bpf_test_rqspinlock.c

+43 −12
Original line number Diff line number Diff line
@@ -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;