1 files changed, 394 insertions, 0 deletions

diff --git a/tools/testing/selftests/net/bench/page_pool/time_bench.c b/tools/testing/selftests/net/bench/page_pool/time_bench.c
new file mode 100644
index 000000000000..073bb36ec5f2
--- /dev/null
+++ b/tools/testing/selftests/net/bench/page_pool/time_bench.c
@@ -0,0 +1,394 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Benchmarking code execution time inside the kernel
+ *
+ * Copyright (C) 2014, Red Hat, Inc., Jesper Dangaard Brouer
+ */
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/time.h>
+
+#include <linux/perf_event.h> /* perf_event_create_kernel_counter() */
+
+/* For concurrency testing */
+#include <linux/completion.h>
+#include <linux/sched.h>
+#include <linux/workqueue.h>
+#include <linux/kthread.h>
+
+#include "time_bench.h"
+
+static int verbose = 1;
+
+/** TSC (Time-Stamp Counter) based **
+ * See: linux/time_bench.h
+ *  tsc_start_clock() and tsc_stop_clock()
+ */
+
+/** Wall-clock based **
+ */
+
+/** PMU (Performance Monitor Unit) based **
+ */
+#define PERF_FORMAT                                                            \
+	(PERF_FORMAT_GROUP | PERF_FORMAT_ID | PERF_FORMAT_TOTAL_TIME_ENABLED | \
+	 PERF_FORMAT_TOTAL_TIME_RUNNING)
+
+struct raw_perf_event {
+	uint64_t config; /* event */
+	uint64_t config1; /* umask */
+	struct perf_event *save;
+	char *desc;
+};
+
+/* if HT is enable a maximum of 4 events (5 if one is instructions
+ * retired can be specified, if HT is disabled a maximum of 8 (9 if
+ * one is instructions retired) can be specified.
+ *
+ * From Table 19-1. Architectural Performance Events
+ * Architectures Software Developer’s Manual Volume 3: System Programming
+ * Guide
+ */
+struct raw_perf_event perf_events[] = {
+	{ 0x3c, 0x00, NULL, "Unhalted CPU Cycles" },
+	{ 0xc0, 0x00, NULL, "Instruction Retired" }
+};
+
+#define NUM_EVTS (ARRAY_SIZE(perf_events))
+
+/* WARNING: PMU config is currently broken!
+ */
+bool time_bench_PMU_config(bool enable)
+{
+	int i;
+	struct perf_event_attr perf_conf;
+	struct perf_event *perf_event;
+	int cpu;
+
+	preempt_disable();
+	cpu = smp_processor_id();
+	pr_info("DEBUG: cpu:%d\n", cpu);
+	preempt_enable();
+
+	memset(&perf_conf, 0, sizeof(struct perf_event_attr));
+	perf_conf.type           = PERF_TYPE_RAW;
+	perf_conf.size           = sizeof(struct perf_event_attr);
+	perf_conf.read_format    = PERF_FORMAT;
+	perf_conf.pinned         = 1;
+	perf_conf.exclude_user   = 1; /* No userspace events */
+	perf_conf.exclude_kernel = 0; /* Only kernel events */
+
+	for (i = 0; i < NUM_EVTS; i++) {
+		perf_conf.disabled = enable;
+		//perf_conf.disabled = (i == 0) ? 1 : 0;
+		perf_conf.config   = perf_events[i].config;
+		perf_conf.config1  = perf_events[i].config1;
+		if (verbose)
+			pr_info("%s() enable PMU counter: %s\n",
+				__func__, perf_events[i].desc);
+		perf_event = perf_event_create_kernel_counter(&perf_conf, cpu,
+							      NULL /* task */,
+							      NULL /* overflow_handler*/,
+							      NULL /* context */);
+		if (perf_event) {
+			perf_events[i].save = perf_event;
+			pr_info("%s():DEBUG perf_event success\n", __func__);
+
+			perf_event_enable(perf_event);
+		} else {
+			pr_info("%s():DEBUG perf_event is NULL\n", __func__);
+		}
+	}
+
+	return true;
+}
+
+/** Generic functions **
+ */
+
+/* Calculate stats, store results in record */
+bool time_bench_calc_stats(struct time_bench_record *rec)
+{
+#define NANOSEC_PER_SEC 1000000000 /* 10^9 */
+	uint64_t ns_per_call_tmp_rem = 0;
+	uint32_t ns_per_call_remainder = 0;
+	uint64_t pmc_ipc_tmp_rem = 0;
+	uint32_t pmc_ipc_remainder = 0;
+	uint32_t pmc_ipc_div = 0;
+	uint32_t invoked_cnt_precision = 0;
+	uint32_t invoked_cnt = 0; /* 32-bit due to div_u64_rem() */
+
+	if (rec->flags & TIME_BENCH_LOOP) {
+		if (rec->invoked_cnt < 1000) {
+			pr_err("ERR: need more(>1000) loops(%llu) for timing\n",
+			       rec->invoked_cnt);
+			return false;
+		}
+		if (rec->invoked_cnt > ((1ULL << 32) - 1)) {
+			/* div_u64_rem() can only support div with 32bit*/
+			pr_err("ERR: Invoke cnt(%llu) too big overflow 32bit\n",
+			       rec->invoked_cnt);
+			return false;
+		}
+		invoked_cnt = (uint32_t)rec->invoked_cnt;
+	}
+
+	/* TSC (Time-Stamp Counter) records */
+	if (rec->flags & TIME_BENCH_TSC) {
+		rec->tsc_interval = rec->tsc_stop - rec->tsc_start;
+		if (rec->tsc_interval == 0) {
+			pr_err("ABORT: timing took ZERO TSC time\n");
+			return false;
+		}
+		/* Calculate stats */
+		if (rec->flags & TIME_BENCH_LOOP)
+			rec->tsc_cycles = rec->tsc_interval / invoked_cnt;
+		else
+			rec->tsc_cycles = rec->tsc_interval;
+	}
+
+	/* Wall-clock time calc */
+	if (rec->flags & TIME_BENCH_WALLCLOCK) {
+		rec->time_start = rec->ts_start.tv_nsec +
+				  (NANOSEC_PER_SEC * rec->ts_start.tv_sec);
+		rec->time_stop = rec->ts_stop.tv_nsec +
+				 (NANOSEC_PER_SEC * rec->ts_stop.tv_sec);
+		rec->time_interval = rec->time_stop - rec->time_start;
+		if (rec->time_interval == 0) {
+			pr_err("ABORT: timing took ZERO wallclock time\n");
+			return false;
+		}
+		/* Calculate stats */
+		/*** Division in kernel it tricky ***/
+		/* Orig: time_sec = (time_interval / NANOSEC_PER_SEC); */
+		/* remainder only correct because NANOSEC_PER_SEC is 10^9 */
+		rec->time_sec = div_u64_rem(rec->time_interval, NANOSEC_PER_SEC,
+					    &rec->time_sec_remainder);
+		//TODO: use existing struct timespec records instead of div?
+
+		if (rec->flags & TIME_BENCH_LOOP) {
+			/*** Division in kernel it tricky ***/
+			/* Orig: ns = ((double)time_interval / invoked_cnt); */
+			/* First get quotient */
+			rec->ns_per_call_quotient =
+				div_u64_rem(rec->time_interval, invoked_cnt,
+					    &ns_per_call_remainder);
+			/* Now get decimals .xxx precision (incorrect roundup)*/
+			ns_per_call_tmp_rem = ns_per_call_remainder;
+			invoked_cnt_precision = invoked_cnt / 1000;
+			if (invoked_cnt_precision > 0) {
+				rec->ns_per_call_decimal =
+					div_u64_rem(ns_per_call_tmp_rem,
+						    invoked_cnt_precision,
+						    &ns_per_call_remainder);
+			}
+		}
+	}
+
+	/* Performance Monitor Unit (PMU) counters */
+	if (rec->flags & TIME_BENCH_PMU) {
+		//FIXME: Overflow handling???
+		rec->pmc_inst = rec->pmc_inst_stop - rec->pmc_inst_start;
+		rec->pmc_clk = rec->pmc_clk_stop - rec->pmc_clk_start;
+
+		/* Calc Instruction Per Cycle (IPC) */
+		/* First get quotient */
+		rec->pmc_ipc_quotient = div_u64_rem(rec->pmc_inst, rec->pmc_clk,
+						    &pmc_ipc_remainder);
+		/* Now get decimals .xxx precision (incorrect roundup)*/
+		pmc_ipc_tmp_rem = pmc_ipc_remainder;
+		pmc_ipc_div = rec->pmc_clk / 1000;
+		if (pmc_ipc_div > 0) {
+			rec->pmc_ipc_decimal = div_u64_rem(pmc_ipc_tmp_rem,
+							   pmc_ipc_div,
+							   &pmc_ipc_remainder);
+		}
+	}
+
+	return true;
+}
+
+/* Generic function for invoking a loop function and calculating
+ * execution time stats.  The function being called/timed is assumed
+ * to perform a tight loop, and update the timing record struct.
+ */
+bool time_bench_loop(uint32_t loops, int step, char *txt, void *data,
+		     int (*func)(struct time_bench_record *record, void *data))
+{
+	struct time_bench_record rec;
+
+	/* Setup record */
+	memset(&rec, 0, sizeof(rec)); /* zero func might not update all */
+	rec.version_abi = 1;
+	rec.loops       = loops;
+	rec.step        = step;
+	rec.flags       = (TIME_BENCH_LOOP | TIME_BENCH_TSC | TIME_BENCH_WALLCLOCK);
+
+	/*** Loop function being timed ***/
+	if (!func(&rec, data)) {
+		pr_err("ABORT: function being timed failed\n");
+		return false;
+	}
+
+	if (rec.invoked_cnt < loops)
+		pr_warn("WARNING: Invoke count(%llu) smaller than loops(%d)\n",
+			rec.invoked_cnt, loops);
+
+	/* Calculate stats */
+	time_bench_calc_stats(&rec);
+
+	pr_info("Type:%s Per elem: %llu cycles(tsc) %llu.%03llu ns (step:%d) - (measurement period time:%llu.%09u sec time_interval:%llu) - (invoke count:%llu tsc_interval:%llu)\n",
+		txt, rec.tsc_cycles, rec.ns_per_call_quotient,
+		rec.ns_per_call_decimal, rec.step, rec.time_sec,
+		rec.time_sec_remainder, rec.time_interval, rec.invoked_cnt,
+		rec.tsc_interval);
+	if (rec.flags & TIME_BENCH_PMU)
+		pr_info("Type:%s PMU inst/clock%llu/%llu = %llu.%03llu IPC (inst per cycle)\n",
+			txt, rec.pmc_inst, rec.pmc_clk, rec.pmc_ipc_quotient,
+			rec.pmc_ipc_decimal);
+	return true;
+}
+
+/* Function getting invoked by kthread */
+static int invoke_test_on_cpu_func(void *private)
+{
+	struct time_bench_cpu *cpu = private;
+	struct time_bench_sync *sync = cpu->sync;
+	cpumask_t newmask = CPU_MASK_NONE;
+	void *data = cpu->data;
+
+	/* Restrict CPU */
+	cpumask_set_cpu(cpu->rec.cpu, &newmask);
+	set_cpus_allowed_ptr(current, &newmask);
+
+	/* Synchronize start of concurrency test */
+	atomic_inc(&sync->nr_tests_running);
+	wait_for_completion(&sync->start_event);
+
+	/* Start benchmark function */
+	if (!cpu->bench_func(&cpu->rec, data)) {
+		pr_err("ERROR: function being timed failed on CPU:%d(%d)\n",
+		       cpu->rec.cpu, smp_processor_id());
+	} else {
+		if (verbose)
+			pr_info("SUCCESS: ran on CPU:%d(%d)\n", cpu->rec.cpu,
+				smp_processor_id());
+	}
+	cpu->did_bench_run = true;
+
+	/* End test */
+	atomic_dec(&sync->nr_tests_running);
+	/*  Wait for kthread_stop() telling us to stop */
+	while (!kthread_should_stop()) {
+		set_current_state(TASK_INTERRUPTIBLE);
+		schedule();
+	}
+	__set_current_state(TASK_RUNNING);
+	return 0;
+}
+
+void time_bench_print_stats_cpumask(const char *desc,
+				    struct time_bench_cpu *cpu_tasks,
+				    const struct cpumask *mask)
+{
+	uint64_t average = 0;
+	int cpu;
+	int step = 0;
+	struct sum {
+		uint64_t tsc_cycles;
+		int records;
+	} sum = { 0 };
+
+	/* Get stats */
+	for_each_cpu(cpu, mask) {
+		struct time_bench_cpu *c = &cpu_tasks[cpu];
+		struct time_bench_record *rec = &c->rec;
+
+		/* Calculate stats */
+		time_bench_calc_stats(rec);
+
+		pr_info("Type:%s CPU(%d) %llu cycles(tsc) %llu.%03llu ns (step:%d) - (measurement period time:%llu.%09u sec time_interval:%llu) - (invoke count:%llu tsc_interval:%llu)\n",
+			desc, cpu, rec->tsc_cycles, rec->ns_per_call_quotient,
+			rec->ns_per_call_decimal, rec->step, rec->time_sec,
+			rec->time_sec_remainder, rec->time_interval,
+			rec->invoked_cnt, rec->tsc_interval);
+
+		/* Collect average */
+		sum.records++;
+		sum.tsc_cycles += rec->tsc_cycles;
+		step = rec->step;
+	}
+
+	if (sum.records) /* avoid div-by-zero */
+		average = sum.tsc_cycles / sum.records;
+	pr_info("Sum Type:%s Average: %llu cycles(tsc) CPUs:%d step:%d\n", desc,
+		average, sum.records, step);
+}
+
+void time_bench_run_concurrent(uint32_t loops, int step, void *data,
+			       const struct cpumask *mask, /* Support masking outsome CPUs*/
+			       struct time_bench_sync *sync,
+			       struct time_bench_cpu *cpu_tasks,
+			       int (*func)(struct time_bench_record *record, void *data))
+{
+	int cpu, running = 0;
+
+	if (verbose) // DEBUG
+		pr_warn("%s() Started on CPU:%d\n", __func__,
+			smp_processor_id());
+
+	/* Reset sync conditions */
+	atomic_set(&sync->nr_tests_running, 0);
+	init_completion(&sync->start_event);
+
+	/* Spawn off jobs on all CPUs */
+	for_each_cpu(cpu, mask) {
+		struct time_bench_cpu *c = &cpu_tasks[cpu];
+
+		running++;
+		c->sync = sync; /* Send sync variable along */
+		c->data = data; /* Send opaque along */
+
+		/* Init benchmark record */
+		memset(&c->rec, 0, sizeof(struct time_bench_record));
+		c->rec.version_abi = 1;
+		c->rec.loops       = loops;
+		c->rec.step        = step;
+		c->rec.flags       = (TIME_BENCH_LOOP | TIME_BENCH_TSC |
+				      TIME_BENCH_WALLCLOCK);
+		c->rec.cpu = cpu;
+		c->bench_func = func;
+		c->task = kthread_run(invoke_test_on_cpu_func, c,
+				      "time_bench%d", cpu);
+		if (IS_ERR(c->task)) {
+			pr_err("%s(): Failed to start test func\n", __func__);
+			return; /* Argh, what about cleanup?! */
+		}
+	}
+
+	/* Wait until all processes are running */
+	while (atomic_read(&sync->nr_tests_running) < running) {
+		set_current_state(TASK_UNINTERRUPTIBLE);
+		schedule_timeout(10);
+	}
+	/* Kick off all CPU concurrently on completion event */
+	complete_all(&sync->start_event);
+
+	/* Wait for CPUs to finish */
+	while (atomic_read(&sync->nr_tests_running)) {
+		set_current_state(TASK_UNINTERRUPTIBLE);
+		schedule_timeout(10);
+	}
+
+	/* Stop the kthreads */
+	for_each_cpu(cpu, mask) {
+		struct time_bench_cpu *c = &cpu_tasks[cpu];
+
+		kthread_stop(c->task);
+	}
+
+	if (verbose) // DEBUG - happens often, finish on another CPU
+		pr_warn("%s() Finished on CPU:%d\n", __func__,
+			smp_processor_id());
+}