[Linuxarm] Re: [PATCH net-next v2 1/2] selftests/ptr_ring: add benchmark application for ptr_ring

On Fri, Jun 25, 2021 at 11:18:55AM +0800, Yunsheng Lin wrote:

Currently ptr_ring selftest is embedded within the virtio selftest, which involves some specific virtio operation, such as notifying and kicking.

As ptr_ring has been used by various subsystems, it deserves it's owner's selftest in order to benchmark different usecase of ptr_ring, such as page pool and pfifo_fast qdisc.

So add a simple application to benchmark ptr_ring performance. Currently two test mode is supported: Mode 0: Both enqueuing and dequeuing is done in a single thread, it is called simple test mode in the test app. Mode 1: Enqueuing and dequeuing is done in different thread concurrently, also known as SPSC(single-producer/ single-consumer) test.

The multi-producer/single-consumer test for pfifo_fast case is not added yet, which can be added if using CAS atomic operation to enable lockless multi-producer is proved to be better than using r->producer_lock.

Only supported on x86 and arm64 for now.

Signed-off-by: Yunsheng Lin linyunsheng@huawei.com

MAINTAINERS | 5 + tools/testing/selftests/ptr_ring/Makefile | 6 + tools/testing/selftests/ptr_ring/ptr_ring_test.c | 249 +++++++++++++++++++++++ tools/testing/selftests/ptr_ring/ptr_ring_test.h | 150 ++++++++++++++ 4 files changed, 410 insertions(+) create mode 100644 tools/testing/selftests/ptr_ring/Makefile create mode 100644 tools/testing/selftests/ptr_ring/ptr_ring_test.c create mode 100644 tools/testing/selftests/ptr_ring/ptr_ring_test.h

diff --git a/MAINTAINERS b/MAINTAINERS index cc375fd..1227022 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -14847,6 +14847,11 @@ F: drivers/net/phy/dp83640* F: drivers/ptp/* F: include/linux/ptp_cl*

+PTR RING BENCHMARK +M: Yunsheng Lin linyunsheng@huawei.com +L: netdev@vger.kernel.org +F: tools/testing/selftests/ptr_ring/

PTRACE SUPPORT M: Oleg Nesterov oleg@redhat.com S: Maintained diff --git a/tools/testing/selftests/ptr_ring/Makefile b/tools/testing/selftests/ptr_ring/Makefile new file mode 100644 index 0000000..346dea9 --- /dev/null +++ b/tools/testing/selftests/ptr_ring/Makefile @@ -0,0 +1,6 @@ +# SPDX-License-Identifier: GPL-2.0 +LDLIBS = -lpthread

+TEST_GEN_PROGS := ptr_ring_test

+include ../lib.mk diff --git a/tools/testing/selftests/ptr_ring/ptr_ring_test.c b/tools/testing/selftests/ptr_ring/ptr_ring_test.c new file mode 100644 index 0000000..4f32d3d --- /dev/null +++ b/tools/testing/selftests/ptr_ring/ptr_ring_test.c @@ -0,0 +1,249 @@ +// SPDX-License-Identifier: GPL-2.0-only

Can we keep this GPL-2.0-or-later same as ptr ring itself? Encourages reuse ...

+/*

• • Copyright (C) 2021 HiSilicon Limited.
• */

+#include <stdio.h> +#include <stdlib.h> +#include <unistd.h> +#include <string.h> +#include <errno.h> +#include <sys/time.h> +#include <malloc.h> +#include <assert.h> +#include <stdbool.h> +#include <pthread.h>

+#include "ptr_ring_test.h" +#include "../../../../include/linux/ptr_ring.h"

+#define MIN_RING_SIZE 2 +#define MAX_RING_SIZE 10000000

+static struct ptr_ring ring ____cacheline_aligned_in_smp;

+struct worker_info {

• pthread_t tid;
• int test_count;
• bool error;
• long duration_us;

+};

+static void *produce_worker(void *arg) +{

• struct worker_info *info = arg;
• struct timeval start, end;
• unsigned long i = 0;
• long sec, us;
• int ret;
• gettimeofday(&start, NULL);
• while (++i <= info->test_count) {

• while (__ptr_ring_full(&ring))
  

• 	cpu_relax();
  

• ret = __ptr_ring_produce(&ring, (void *)i);
  

• if (ret) {
  

• 	fprintf(stderr, "produce failed: %d\n", ret);
  

• 	info->error = true;
  

• 	return NULL;
  

• }
  

• }
• gettimeofday(&end, NULL);
• sec = (end.tv_sec - start.tv_sec);
• us = ((sec * 1000000) + end.tv_usec) - (start.tv_usec);
• info->duration_us = us;
• info->error = false;
• return NULL;

+}

perf does all of this and more. Let's not reinvent the wheel - just run the test.

+static void *consume_worker(void *arg) +{

• struct worker_info *info = arg;
• struct timeval start, end;
• unsigned long i = 0;
• long sec, us;
• int *ptr;
• gettimeofday(&start, NULL);
• while (++i <= info->test_count) {

• while (__ptr_ring_empty(&ring))
  

• 	cpu_relax();
  

• ptr = __ptr_ring_consume(&ring);
  

• if ((unsigned long)ptr != i) {
  

• 	fprintf(stderr, "consumer failed, ptr: %lu, i: %lu\n",
  

• 		(unsigned long)ptr, i);
  

• 	info->error = true;
  

• 	return NULL;
  

• }
  

• }
• gettimeofday(&end, NULL);
• if (!__ptr_ring_empty(&ring)) {

• fprintf(stderr, "ring should be empty, test failed\n");
  

• info->error = true;
  

• return NULL;
  

• }
• sec = (end.tv_sec - start.tv_sec);
• us = ((sec * 1000000) + end.tv_usec) - (start.tv_usec);
• info->duration_us = us;
• info->error = false;
• return NULL;

+}

+/* test case for single producer single consumer */ +static void spsc_test(int size, int count) +{

• struct worker_info producer, consumer;
• pthread_attr_t attr;
• void *res;
• int ret;
• ret = ptr_ring_init(&ring, size, 0);
• if (ret) {

• fprintf(stderr, "init failed: %d\n", ret);
  

• return;
  

• }
• producer.test_count = count;
• consumer.test_count = count;
• ret = pthread_attr_init(&attr);
• if (ret) {

• fprintf(stderr, "pthread attr init failed: %d\n", ret);
  

• goto out;
  

• }
• ret = pthread_create(&producer.tid, &attr,

• 	     produce_worker, &producer);
  

• if (ret) {

• fprintf(stderr, "create producer thread failed: %d\n", ret);
  

• goto out;
  

• }
• ret = pthread_create(&consumer.tid, &attr,

• 	     consume_worker, &consumer);
  

• if (ret) {

• fprintf(stderr, "create consumer thread failed: %d\n", ret);
  

• goto out;
  

• }
• ret = pthread_join(producer.tid, &res);
• if (ret) {

• fprintf(stderr, "join producer thread failed: %d\n", ret);
  

• goto out;
  

• }
• ret = pthread_join(consumer.tid, &res);
• if (ret) {

• fprintf(stderr, "join consumer thread failed: %d\n", ret);
  

• goto out;
  

• }
• if (producer.error || consumer.error) {

• fprintf(stderr, "spsc test failed\n");
  

• goto out;
  

• }
• printf("ptr_ring(size:%d) perf spsc test for %d times, took %ld us + %ld us\n",

•       size, count, producer.duration_us, consumer.duration_us);
  

+out:

• ptr_ring_cleanup(&ring, NULL);

+}

+static void simple_test(int size, int count) +{

• struct timeval start, end;
• long sec, us;
• int i = 0;
• int *ptr;
• int ret;
• ret = ptr_ring_init(&ring, size, 0);
• if (ret) {

• fprintf(stderr, "init failed: %d\n", ret);
  

• return;
  

• }
• gettimeofday(&start, NULL);
• while (++i <= count) {

• ret = __ptr_ring_produce(&ring, &count);
  

• if (ret) {
  

• 	fprintf(stderr, "produce failed: %d\n", ret);
  

• 	goto out;
  

• }
  

• ptr = __ptr_ring_consume(&ring);
  

• if (ptr != &count)  {
  

• 	fprintf(stderr, "consume failed: %p\n", ptr);
  

• 	goto out;
  

• }
  

• }
• gettimeofday(&end, NULL);
• sec = (end.tv_sec - start.tv_sec);
• us = ((sec * 1000000) + end.tv_usec) - (start.tv_usec);
• printf("ptr_ring(size:%d) perf simple test for %d times, took %ld us\n",

•       size, count, us);
  

+out:

• ptr_ring_cleanup(&ring, NULL);

+}

+int main(int argc, char *argv[]) +{

• int count = 1000000;
• int size = 1000;
• int mode = 0;
• int opt;
• while ((opt = getopt(argc, argv, "N:s:m:")) != -1) {

• switch (opt) {
  

• case 'N':
  

• 	count = atoi(optarg);
  

• 	break;
  

• case 's':
  

• 	size = atoi(optarg);
  

• 	break;
  

• case 'm':
  

• 	mode = atoi(optarg);
  

• 	break;
  

• default:
  

• 	return -1;
  

• }
  

• }
• if (count <= 0) {

• fprintf(stderr, "invalid test count, must be > 0\n");
  

• return -1;
  

• }
• if (size < MIN_RING_SIZE || size > MAX_RING_SIZE) {

• fprintf(stderr, "invalid ring size, must be in %d-%d\n",
  

• 	MIN_RING_SIZE, MAX_RING_SIZE);
  

• return -1;
  

• }
• switch (mode) {
• case 0:

• simple_test(size, count);
  

• break;
  

• case 1:

• spsc_test(size, count);
  

• break;
  

• default:

• fprintf(stderr, "invalid test mode\n");
  

• return -1;
  

• }
• return 0;

+} diff --git a/tools/testing/selftests/ptr_ring/ptr_ring_test.h b/tools/testing/selftests/ptr_ring/ptr_ring_test.h new file mode 100644 index 0000000..6bf2494 --- /dev/null +++ b/tools/testing/selftests/ptr_ring/ptr_ring_test.h @@ -0,0 +1,150 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */

We already have hacks like this in the virtio test. Let's refactor not duplicate please.

+#ifndef _TEST_PTR_RING_IMPL_H +#define _TEST_PTR_RING_IMPL_H

+#if defined(__x86_64__) || defined(__i386__) +static inline void cpu_relax(void) +{

• asm volatile ("rep; nop" ::: "memory");

+} +#elif defined(__aarch64__) +static inline void cpu_relax(void) +{

• asm volatile("yield" ::: "memory");

+} +#else +#define cpu_relax() assert(0) +#endif

+static inline void barrier(void) +{

• asm volatile("" ::: "memory");

+}

+/*

• • This abuses the atomic builtins for thread fences, and
• • adds a compiler barrier.
• */

+#define smp_release() do { \

• barrier(); \
• __atomic_thread_fence(__ATOMIC_RELEASE); \

+} while (0)

+#define smp_acquire() do { \

• __atomic_thread_fence(__ATOMIC_ACQUIRE); \
• barrier(); \

+} while (0)

+#if defined(__i386__) || defined(__x86_64__) +#define smp_wmb() barrier() +#else +#define smp_wmb() smp_release() +#endif

+#define READ_ONCE(x) (*(volatile typeof(x) *)&(x)) +#define WRITE_ONCE(x, val) ((*(volatile typeof(x) *)&(x)) = (val)) +#define SMP_CACHE_BYTES 64 +#define cache_line_size SMP_CACHE_BYTES +#define unlikely(x) (__builtin_expect(!!(x), 0)) +#define likely(x) (__builtin_expect(!!(x), 1)) +#define ALIGN(x, a) (((x) + (a) - 1) / (a) * (a)) +#define SIZE_MAX (~(size_t)0) +#define KMALLOC_MAX_SIZE SIZE_MAX +#define spinlock_t pthread_spinlock_t +#define gfp_t int +#define __GFP_ZERO 0x1

+#define ____cacheline_aligned_in_smp __attribute__((aligned(SMP_CACHE_BYTES)))

+static void *kmalloc(unsigned int size, gfp_t gfp) +{

• void *p;
• p = memalign(64, size);
• if (!p)

• return p;
  

• if (gfp & __GFP_ZERO)

• memset(p, 0, size);
  

• return p;

+}

+static inline void *kzalloc(unsigned int size, gfp_t flags) +{

• return kmalloc(size, flags | __GFP_ZERO);

+}

+static inline void *kmalloc_array(size_t n, size_t size, gfp_t flags) +{

• if (size != 0 && n > SIZE_MAX / size)

• return NULL;
  

• return kmalloc(n * size, flags);

+}

+static inline void *kcalloc(size_t n, size_t size, gfp_t flags) +{

• return kmalloc_array(n, size, flags | __GFP_ZERO);

+}

+static void kfree(void *p) +{

• free(p);

+}

+#define kvmalloc_array kmalloc_array +#define kvfree kfree

+static void spin_lock_init(spinlock_t *lock) +{

• int r = pthread_spin_init(lock, 0);
• assert(!r);

+}

+static void spin_lock(spinlock_t *lock) +{

• int ret = pthread_spin_lock(lock);
• assert(!ret);

+}

+static void spin_unlock(spinlock_t *lock) +{

• int ret = pthread_spin_unlock(lock);
• assert(!ret);

+}

+static void spin_lock_bh(spinlock_t *lock) +{

• spin_lock(lock);

+}

+static void spin_unlock_bh(spinlock_t *lock) +{

• spin_unlock(lock);

+}

+static void spin_lock_irq(spinlock_t *lock) +{

• spin_lock(lock);

+}

+static void spin_unlock_irq(spinlock_t *lock) +{

• spin_unlock(lock);

+}

+static void spin_lock_irqsave(spinlock_t *lock, unsigned long f) +{

• spin_lock(lock);

+}

+static void spin_unlock_irqrestore(spinlock_t *lock, unsigned long f) +{

• spin_unlock(lock);

+}

+#endif

2.7.4