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authorLennart Poettering <lennart@poettering.net>2013-05-22 16:02:21 +0200
committerLennart Poettering <lennart@poettering.net>2013-05-22 16:04:39 +0200
commit8f155917bf5c11c8f156d7f25f242257d6086cb9 (patch)
tree5b34963cd80961ca0353f93e0598e1a2b6451738 /src
parent2927b326ccf67236e148444679f582ea1437ef5a (diff)
bus: add benchmark tool to determine the right threshold for copying vs. memfd
Diffstat (limited to 'src')
-rw-r--r--src/libsystemd-bus/bus-internal.h2
-rw-r--r--src/libsystemd-bus/bus-kernel.c2
-rw-r--r--src/libsystemd-bus/bus-message.c6
-rw-r--r--src/libsystemd-bus/sd-bus.c1
-rw-r--r--src/libsystemd-bus/test-bus-kernel-benchmark.c225
5 files changed, 233 insertions, 3 deletions
diff --git a/src/libsystemd-bus/bus-internal.h b/src/libsystemd-bus/bus-internal.h
index 147a83c045..30b8d519a0 100644
--- a/src/libsystemd-bus/bus-internal.h
+++ b/src/libsystemd-bus/bus-internal.h
@@ -111,6 +111,8 @@ struct sd_bus {
bool filter_callbacks_modified:1;
bool object_callbacks_modified:1;
+ int use_memfd;
+
void *rbuffer;
size_t rbuffer_size;
diff --git a/src/libsystemd-bus/bus-kernel.c b/src/libsystemd-bus/bus-kernel.c
index 19d274b662..10b7a8aba4 100644
--- a/src/libsystemd-bus/bus-kernel.c
+++ b/src/libsystemd-bus/bus-kernel.c
@@ -326,6 +326,8 @@ int bus_kernel_take_fd(sd_bus *b) {
if (b->is_server)
return -EINVAL;
+ b->use_memfd = 1;
+
if (!b->kdbus_buffer) {
b->kdbus_buffer = mmap(NULL, KDBUS_POOL_SIZE, PROT_READ|PROT_WRITE, MAP_ANONYMOUS|MAP_PRIVATE, -1, 0);
if (b->kdbus_buffer == MAP_FAILED) {
diff --git a/src/libsystemd-bus/bus-message.c b/src/libsystemd-bus/bus-message.c
index e531dec5cd..55c2d62885 100644
--- a/src/libsystemd-bus/bus-message.c
+++ b/src/libsystemd-bus/bus-message.c
@@ -564,7 +564,7 @@ static int message_new_reply(
goto fail;
if (call->sender) {
- r = message_append_field_string(t, SD_BUS_MESSAGE_HEADER_DESTINATION, SD_BUS_TYPE_STRING, call->sender, &t->sender);
+ r = message_append_field_string(t, SD_BUS_MESSAGE_HEADER_DESTINATION, SD_BUS_TYPE_STRING, call->sender, &t->destination);
if (r < 0)
goto fail;
}
@@ -3865,9 +3865,9 @@ int bus_message_seal(sd_bus_message *m, uint64_t serial) {
/* If this is something we can send as memfd, then let's seal
the memfd now. Note that we can send memfds as payload only
for directed messages, and not for broadcasts. */
- if (m->destination) {
+ if (m->destination && m->bus && m->bus->use_memfd) {
MESSAGE_FOREACH_PART(part, i, m)
- if (part->memfd >= 0 && !part->sealed && part->size > MEMFD_MIN_SIZE) {
+ if (part->memfd >= 0 && !part->sealed && (part->size > MEMFD_MIN_SIZE || m->bus->use_memfd < 0)) {
bus_body_part_unmap(part);
if (ioctl(part->memfd, KDBUS_CMD_MEMFD_SEAL_SET, 1) >= 0)
diff --git a/src/libsystemd-bus/sd-bus.c b/src/libsystemd-bus/sd-bus.c
index 7ae32036bd..3f766fb519 100644
--- a/src/libsystemd-bus/sd-bus.c
+++ b/src/libsystemd-bus/sd-bus.c
@@ -2514,6 +2514,7 @@ int sd_bus_call_method(
int r;
if (!bus)
+
return -EINVAL;
if (!BUS_IS_OPEN(bus->state))
return -ENOTCONN;
diff --git a/src/libsystemd-bus/test-bus-kernel-benchmark.c b/src/libsystemd-bus/test-bus-kernel-benchmark.c
new file mode 100644
index 0000000000..403af885c3
--- /dev/null
+++ b/src/libsystemd-bus/test-bus-kernel-benchmark.c
@@ -0,0 +1,225 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+/***
+ This file is part of systemd.
+
+ Copyright 2013 Lennart Poettering
+
+ systemd is free software; you can redistribute it and/or modify it
+ under the terms of the GNU Lesser General Public License as published by
+ the Free Software Foundation; either version 2.1 of the License, or
+ (at your option) any later version.
+
+ systemd is distributed in the hope that it will be useful, but
+ WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public License
+ along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <ctype.h>
+#include <sys/wait.h>
+
+#include "util.h"
+#include "log.h"
+
+#include "sd-bus.h"
+#include "bus-message.h"
+#include "bus-error.h"
+#include "bus-kernel.h"
+#include "bus-internal.h"
+
+#define N_TRIES 500
+#define MAX_SIZE (5*1024*1024)
+
+static void server(sd_bus *b, usec_t *result) {
+ usec_t x = 0;
+ int r;
+
+ for (;;) {
+ _cleanup_bus_message_unref_ sd_bus_message *m = NULL;
+
+ r = sd_bus_process(b, &m);
+ assert_se(r >= 0);
+
+ if (r == 0)
+ assert_se(sd_bus_wait(b, (usec_t) -1) >= 0);
+
+ if (!m)
+ continue;
+
+ /* log_error("huhu %s from %s", sd_bus_message_get_member(m), sd_bus_message_get_sender(m)); */
+
+ if (sd_bus_message_is_method_call(m, "benchmark.server", "Work")) {
+ _cleanup_bus_message_unref_ sd_bus_message *reply = NULL;
+ size_t i, sz;
+ char *q;
+ const char *p;
+
+ assert_se(sd_bus_message_read_array(m, 'y', (const void**) &p, &sz) > 0);
+ assert_se(sd_bus_message_new_method_return(b, m, &reply) >= 0);
+ assert_se(sd_bus_message_append_array_space(reply, 'y', sz, (void**) &q) >= 0);
+
+ x = now(CLOCK_MONOTONIC);
+
+ for (i = 0; i < sz; i++)
+ q[i] = toupper(p[i]);
+
+ x = now(CLOCK_MONOTONIC) - x;
+
+ assert_se(sd_bus_send(b, reply, NULL) >= 0);
+ } else if (sd_bus_message_is_method_call(m, "benchmark.server", "Exit")) {
+ usec_t t;
+
+ assert_se(sd_bus_message_read(m, "t", &t) > 0);
+ assert_se(t >= x);
+ *result = t - x;
+ return;
+
+ } else if (sd_bus_message_is_method_call(m, "benchmark.server", "Ping")) {
+ assert_se(sd_bus_reply_method_return(b, m, "y", 1) >= 0);
+ } else
+ assert_not_reached("Unknown method");
+ }
+}
+
+static void client(sd_bus *b, size_t sz) {
+ _cleanup_bus_message_unref_ sd_bus_message *m = NULL, *reply = NULL;
+ char *p;
+ const char *q;
+ usec_t t;
+ size_t l, i;
+
+ assert_se(sd_bus_call_method(b, ":1.1", "/", "benchmark.server", "Ping", NULL, NULL, NULL) >= 0);
+
+ assert_se(sd_bus_message_new_method_call(b, ":1.1", "/", "benchmark.server", "Work", &m) >= 0);
+ assert_se(sd_bus_message_append_array_space(m, 'y', sz, (void**) &p) >= 0);
+
+ for (i = 0; i < sz; i++)
+ p[i] = 'a' + (char) (i % 26);
+
+ t = now(CLOCK_MONOTONIC);
+ assert_se(sd_bus_send_with_reply_and_block(b, m, 0, NULL, &reply) >= 0);
+ t = now(CLOCK_MONOTONIC) - t;
+
+ assert_se(sd_bus_message_read_array(reply, 'y', (const void**) &q, &l) > 0);
+ assert_se(l == sz);
+
+ for (i = 0; i < sz; i++) {
+ assert_se(q[i] == 'A' + (char) (i % 26));
+ }
+
+ sd_bus_message_unref(m);
+
+ assert_se(sd_bus_message_new_method_call(b, ":1.1", "/", "benchmark.server", "Exit", &m) >= 0);
+ assert_se(sd_bus_message_append(m, "t", t) >= 0);
+ assert_se(sd_bus_send(b, m, NULL) >= 0);
+}
+
+static void run_benchmark(size_t sz, bool force_copy, usec_t *result) {
+
+ _cleanup_close_ int bus_ref = -1;
+ _cleanup_free_ char *bus_name = NULL, *address = NULL;
+ sd_bus *b;
+ int r;
+ pid_t pid;
+
+ bus_ref = bus_kernel_create("deine-mutter", &bus_name);
+ if (bus_ref == -ENOENT)
+ exit(EXIT_TEST_SKIP);
+
+ assert_se(bus_ref >= 0);
+
+ address = strappend("kernel:path=", bus_name);
+ assert_se(address);
+
+ r = sd_bus_new(&b);
+ assert_se(r >= 0);
+
+ b->use_memfd = force_copy ? 0 : -1;
+
+ r = sd_bus_set_address(b, address);
+ assert_se(r >= 0);
+
+ r = sd_bus_start(b);
+ assert_se(r >= 0);
+
+ pid = fork();
+ assert_se(pid >= 0);
+
+ if (pid == 0) {
+ close_nointr_nofail(bus_ref);
+ sd_bus_unref(b);
+
+ r = sd_bus_new(&b);
+ assert_se(r >= 0);
+
+ b->use_memfd = force_copy ? 0 : -1;
+
+ r = sd_bus_set_address(b, address);
+ assert_se(r >= 0);
+
+ r = sd_bus_start(b);
+ assert_se(r >= 0);
+
+ client(b, sz);
+ _exit(0);
+ }
+
+ server(b, result);
+ sd_bus_unref(b);
+
+ assert_se(waitpid(pid, NULL, 0) == pid);
+}
+
+int main(int argc, char *argv[]) {
+ size_t lsize, rsize, csize;
+
+ log_set_max_level(LOG_DEBUG);
+
+ lsize = 1;
+ rsize = MAX_SIZE;
+
+ for (;;) {
+ usec_t copy = 0, memfd = 0;
+ unsigned i;
+
+ csize = (lsize + rsize) / 2;
+
+ log_info("Trying size=%zu", csize);
+
+ if (csize <= lsize)
+ break;
+
+ for (i = 0; i < N_TRIES; i++) {
+ usec_t t;
+
+ run_benchmark(csize, true, &t);
+ copy += t;
+ }
+
+ for (i = 0; i < N_TRIES; i++) {
+ usec_t t;
+
+ run_benchmark(csize, false, &t);
+ memfd += t;
+ }
+
+ copy /= N_TRIES;
+ memfd /= N_TRIES;
+
+ if (copy == memfd)
+ break;
+
+ if (copy < memfd)
+ lsize = csize;
+ else
+ rsize = csize;
+ }
+
+ log_info("Copying/memfd are equally fast at %zu", csize);
+
+ return 0;
+}