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authorMichael S. Tsirkin <mst@redhat.com>2016-01-21 15:44:10 +0300
committerMichael S. Tsirkin <mst@redhat.com>2016-01-26 11:18:30 +0300
commit481eaec37e91e2b33f17275901172f50ce2c71e8 (patch)
treecd0df9f9f652f12820d5f615a0016da3f98839d4 /tools/virtio/ringtest/main.c
parentfb9b050ce9695cf2769a850d94aa2ab39c8c3cd5 (diff)
downloadlinux-481eaec37e91e2b33f17275901172f50ce2c71e8.tar.xz
tools/virtio: add ringtest utilities
This adds micro-benchmarks useful for tuning virtio ring layouts. Three layouts are currently implemented: - virtio 0.9 compatible one - an experimental extension bypassing the ring index, polling ring itself instead - an experimental extension bypassing avail and used ring completely Typical use: sh run-on-all.sh perf stat -r 10 --log-fd 1 -- ./ring It doesn't depend on the kernel directly, but it's handy to have as much virtio stuff as possible in one tree. Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Diffstat (limited to 'tools/virtio/ringtest/main.c')
-rw-r--r--tools/virtio/ringtest/main.c366
1 files changed, 366 insertions, 0 deletions
diff --git a/tools/virtio/ringtest/main.c b/tools/virtio/ringtest/main.c
new file mode 100644
index 000000000000..3a5ff438bd62
--- /dev/null
+++ b/tools/virtio/ringtest/main.c
@@ -0,0 +1,366 @@
+/*
+ * Copyright (C) 2016 Red Hat, Inc.
+ * Author: Michael S. Tsirkin <mst@redhat.com>
+ * This work is licensed under the terms of the GNU GPL, version 2.
+ *
+ * Command line processing and common functions for ring benchmarking.
+ */
+#define _GNU_SOURCE
+#include <getopt.h>
+#include <pthread.h>
+#include <assert.h>
+#include <sched.h>
+#include "main.h"
+#include <sys/eventfd.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <limits.h>
+
+int runcycles = 10000000;
+int max_outstanding = INT_MAX;
+int batch = 1;
+
+bool do_sleep = false;
+bool do_relax = false;
+bool do_exit = true;
+
+unsigned ring_size = 256;
+
+static int kickfd = -1;
+static int callfd = -1;
+
+void notify(int fd)
+{
+ unsigned long long v = 1;
+ int r;
+
+ vmexit();
+ r = write(fd, &v, sizeof v);
+ assert(r == sizeof v);
+ vmentry();
+}
+
+void wait_for_notify(int fd)
+{
+ unsigned long long v = 1;
+ int r;
+
+ vmexit();
+ r = read(fd, &v, sizeof v);
+ assert(r == sizeof v);
+ vmentry();
+}
+
+void kick(void)
+{
+ notify(kickfd);
+}
+
+void wait_for_kick(void)
+{
+ wait_for_notify(kickfd);
+}
+
+void call(void)
+{
+ notify(callfd);
+}
+
+void wait_for_call(void)
+{
+ wait_for_notify(callfd);
+}
+
+void set_affinity(const char *arg)
+{
+ cpu_set_t cpuset;
+ int ret;
+ pthread_t self;
+ long int cpu;
+ char *endptr;
+
+ if (!arg)
+ return;
+
+ cpu = strtol(arg, &endptr, 0);
+ assert(!*endptr);
+
+ assert(cpu >= 0 || cpu < CPU_SETSIZE);
+
+ self = pthread_self();
+ CPU_ZERO(&cpuset);
+ CPU_SET(cpu, &cpuset);
+
+ ret = pthread_setaffinity_np(self, sizeof(cpu_set_t), &cpuset);
+ assert(!ret);
+}
+
+static void run_guest(void)
+{
+ int completed_before;
+ int completed = 0;
+ int started = 0;
+ int bufs = runcycles;
+ int spurious = 0;
+ int r;
+ unsigned len;
+ void *buf;
+ int tokick = batch;
+
+ for (;;) {
+ if (do_sleep)
+ disable_call();
+ completed_before = completed;
+ do {
+ if (started < bufs &&
+ started - completed < max_outstanding) {
+ r = add_inbuf(0, NULL, "Hello, world!");
+ if (__builtin_expect(r == 0, true)) {
+ ++started;
+ if (!--tokick) {
+ tokick = batch;
+ if (do_sleep)
+ kick_available();
+ }
+
+ }
+ } else
+ r = -1;
+
+ /* Flush out completed bufs if any */
+ if (get_buf(&len, &buf)) {
+ ++completed;
+ if (__builtin_expect(completed == bufs, false))
+ return;
+ r = 0;
+ }
+ } while (r == 0);
+ if (completed == completed_before)
+ ++spurious;
+ assert(completed <= bufs);
+ assert(started <= bufs);
+ if (do_sleep) {
+ if (enable_call())
+ wait_for_call();
+ } else {
+ poll_used();
+ }
+ }
+}
+
+static void run_host(void)
+{
+ int completed_before;
+ int completed = 0;
+ int spurious = 0;
+ int bufs = runcycles;
+ unsigned len;
+ void *buf;
+
+ for (;;) {
+ if (do_sleep) {
+ if (enable_kick())
+ wait_for_kick();
+ } else {
+ poll_avail();
+ }
+ if (do_sleep)
+ disable_kick();
+ completed_before = completed;
+ while (__builtin_expect(use_buf(&len, &buf), true)) {
+ if (do_sleep)
+ call_used();
+ ++completed;
+ if (__builtin_expect(completed == bufs, false))
+ return;
+ }
+ if (completed == completed_before)
+ ++spurious;
+ assert(completed <= bufs);
+ if (completed == bufs)
+ break;
+ }
+}
+
+void *start_guest(void *arg)
+{
+ set_affinity(arg);
+ run_guest();
+ pthread_exit(NULL);
+}
+
+void *start_host(void *arg)
+{
+ set_affinity(arg);
+ run_host();
+ pthread_exit(NULL);
+}
+
+static const char optstring[] = "";
+static const struct option longopts[] = {
+ {
+ .name = "help",
+ .has_arg = no_argument,
+ .val = 'h',
+ },
+ {
+ .name = "host-affinity",
+ .has_arg = required_argument,
+ .val = 'H',
+ },
+ {
+ .name = "guest-affinity",
+ .has_arg = required_argument,
+ .val = 'G',
+ },
+ {
+ .name = "ring-size",
+ .has_arg = required_argument,
+ .val = 'R',
+ },
+ {
+ .name = "run-cycles",
+ .has_arg = required_argument,
+ .val = 'C',
+ },
+ {
+ .name = "outstanding",
+ .has_arg = required_argument,
+ .val = 'o',
+ },
+ {
+ .name = "batch",
+ .has_arg = required_argument,
+ .val = 'b',
+ },
+ {
+ .name = "sleep",
+ .has_arg = no_argument,
+ .val = 's',
+ },
+ {
+ .name = "relax",
+ .has_arg = no_argument,
+ .val = 'x',
+ },
+ {
+ .name = "exit",
+ .has_arg = no_argument,
+ .val = 'e',
+ },
+ {
+ }
+};
+
+static void help(void)
+{
+ fprintf(stderr, "Usage: <test> [--help]"
+ " [--host-affinity H]"
+ " [--guest-affinity G]"
+ " [--ring-size R (default: %d)]"
+ " [--run-cycles C (default: %d)]"
+ " [--batch b]"
+ " [--outstanding o]"
+ " [--sleep]"
+ " [--relax]"
+ " [--exit]"
+ "\n",
+ ring_size,
+ runcycles);
+}
+
+int main(int argc, char **argv)
+{
+ int ret;
+ pthread_t host, guest;
+ void *tret;
+ char *host_arg = NULL;
+ char *guest_arg = NULL;
+ char *endptr;
+ long int c;
+
+ kickfd = eventfd(0, 0);
+ assert(kickfd >= 0);
+ callfd = eventfd(0, 0);
+ assert(callfd >= 0);
+
+ for (;;) {
+ int o = getopt_long(argc, argv, optstring, longopts, NULL);
+ switch (o) {
+ case -1:
+ goto done;
+ case '?':
+ help();
+ exit(2);
+ case 'H':
+ host_arg = optarg;
+ break;
+ case 'G':
+ guest_arg = optarg;
+ break;
+ case 'R':
+ ring_size = strtol(optarg, &endptr, 0);
+ assert(ring_size && !(ring_size & (ring_size - 1)));
+ assert(!*endptr);
+ break;
+ case 'C':
+ c = strtol(optarg, &endptr, 0);
+ assert(!*endptr);
+ assert(c > 0 && c < INT_MAX);
+ runcycles = c;
+ break;
+ case 'o':
+ c = strtol(optarg, &endptr, 0);
+ assert(!*endptr);
+ assert(c > 0 && c < INT_MAX);
+ max_outstanding = c;
+ break;
+ case 'b':
+ c = strtol(optarg, &endptr, 0);
+ assert(!*endptr);
+ assert(c > 0 && c < INT_MAX);
+ batch = c;
+ break;
+ case 's':
+ do_sleep = true;
+ break;
+ case 'x':
+ do_relax = true;
+ break;
+ case 'e':
+ do_exit = true;
+ break;
+ default:
+ help();
+ exit(4);
+ break;
+ }
+ }
+
+ /* does nothing here, used to make sure all smp APIs compile */
+ smp_acquire();
+ smp_release();
+ smp_mb();
+done:
+
+ if (batch > max_outstanding)
+ batch = max_outstanding;
+
+ if (optind < argc) {
+ help();
+ exit(4);
+ }
+ alloc_ring();
+
+ ret = pthread_create(&host, NULL, start_host, host_arg);
+ assert(!ret);
+ ret = pthread_create(&guest, NULL, start_guest, guest_arg);
+ assert(!ret);
+
+ ret = pthread_join(guest, &tret);
+ assert(!ret);
+ ret = pthread_join(host, &tret);
+ assert(!ret);
+ return 0;
+}