From 36fe1db1c250c97ceb3211f98a13e0f8d70cc5b6 Mon Sep 17 00:00:00 2001
From: Bob Chen <beef9999@qq.com>
Date: Fri, 16 Feb 2024 23:53:03 +0800
Subject: [PATCH] Add io perf benchmark

---
 examples/CMakeLists.txt   |   5 ++
 examples/perf/io-perf.cpp | 108 ++++++++++++++++++++++++++++++++++++++
 2 files changed, 113 insertions(+)
 create mode 100644 examples/perf/io-perf.cpp

diff --git a/examples/CMakeLists.txt b/examples/CMakeLists.txt
index b0cc4a1e..c7b25a1b 100644
--- a/examples/CMakeLists.txt
+++ b/examples/CMakeLists.txt
@@ -6,6 +6,11 @@ target_link_libraries(simple-example PRIVATE photon_static)
 add_executable(net-perf perf/net-perf.cpp)
 target_link_libraries(net-perf PRIVATE photon_static)
 
+if (NOT APPLE)
+add_executable(io-perf perf/io-perf.cpp)
+target_link_libraries(io-perf PRIVATE photon_static)
+endif ()
+
 add_executable(rpc-example-client rpc/client.cpp rpc/client_main.cpp)
 target_link_libraries(rpc-example-client PRIVATE photon_static)
 
diff --git a/examples/perf/io-perf.cpp b/examples/perf/io-perf.cpp
new file mode 100644
index 00000000..05982383
--- /dev/null
+++ b/examples/perf/io-perf.cpp
@@ -0,0 +1,108 @@
+/*
+Copyright 2022 The Photon Authors
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+#include <fcntl.h>
+#include <sys/statfs.h>
+
+#include <vector>
+#include <random>
+#include <gflags/gflags.h>
+
+#include <photon/photon.h>
+#include <photon/common/alog.h>
+#include <photon/common/io-alloc.h>
+#include <photon/fs/localfs.h>
+#include <photon/thread/thread11.h>
+
+const static size_t LAST_IO_BOUNDARY = 2 * 1024 * 1024;
+static std::random_device rd;
+static std::mt19937 gen(rd());
+static uint64_t qps = 0;
+
+DEFINE_uint64(io_depth, 128, "io depth");
+DEFINE_string(disk_path, "", "disk path. For example, /dev/nvme2n1");
+DEFINE_uint64(disk_size, 0, "disk size. For example, 1000000000000. No need to align. Can be approximate number");
+DEFINE_uint64(io_size, 4096, "io size");
+DEFINE_bool(io_uring, false, "test io_uring or aio");
+
+#define ROUND_DOWN(N, S) ((N) & ~((S) - 1))
+
+static uint64_t random(uint64_t N) {
+    std::uniform_int_distribution<size_t> distrib(0, N);
+    return distrib(gen);
+}
+
+static void show_qps_loop() {
+    while (true) {
+        photon::thread_sleep(1);
+        LOG_INFO("QPS: `, BW: ` MB/s", qps, qps * FLAGS_io_size / 1024 / 1024);
+        qps = 0;
+    }
+}
+
+static void infinite_read(const uint64_t max_offset, photon::fs::IFile* src_file, IOAlloc* alloc) {
+    size_t count = FLAGS_io_size;
+    void* buf = alloc->alloc(count);
+    while (true) {
+        uint64_t offset = ROUND_DOWN(random(max_offset), count);
+        int ret = src_file->pread(buf, FLAGS_io_size, offset);
+        if (ret != (int) count) {
+            LOG_ERROR("read fail, count `, offset `, ret `, errno `", count, offset, ret, ERRNO());
+            exit(1);
+        }
+        qps++;
+    }
+}
+
+int main(int argc, char** arg) {
+    gflags::ParseCommandLineFlags(&argc, &arg, true);
+    log_output_level = ALOG_INFO;
+    if (FLAGS_disk_path.empty()) {
+        LOG_ERROR_RETURN(0, -1, "need disk path");
+    }
+    if (FLAGS_disk_size < 10'000'000'000UL) {
+        LOG_ERROR_RETURN(0, -1, "need disk size");
+    }
+    LOG_INFO("Specify disk ` size `", FLAGS_disk_path.c_str(), FLAGS_disk_size);
+
+    int ev_engine = FLAGS_io_uring ? photon::INIT_EVENT_IOURING : photon::INIT_EVENT_EPOLL;
+    int io_engine = FLAGS_io_uring ? photon::INIT_IO_NONE : photon::INIT_IO_LIBAIO;
+    int fs_io_engine = FLAGS_io_uring ? photon::fs::ioengine_iouring : photon::fs::ioengine_libaio;
+
+    int ret = photon::init(ev_engine, io_engine, photon::PhotonOptions{.libaio_queue_depth = 512});
+    if (ret != 0) {
+        LOG_ERROR_RETURN(0, -1, "init failed");
+    }
+
+    photon::thread_create11(show_qps_loop);
+
+    // Read only open with direct-IO
+    int flags = O_RDONLY | O_DIRECT;
+    auto file = photon::fs::open_localfile_adaptor(FLAGS_disk_path.c_str(), flags, 0644, fs_io_engine);
+    if (!file) {
+        LOG_ERROR_RETURN(0, -1, "open failed");
+    }
+
+    // The allocator is only for aio 4K mem align
+    // io_uring doesn't require mem align
+    AlignedAlloc io_alloc(4096);
+    uint64_t max_offset = FLAGS_disk_size - LAST_IO_BOUNDARY;
+
+    for (uint64_t i = 0; i < FLAGS_io_depth; i++) {
+        photon::thread_create11(infinite_read, max_offset, file, &io_alloc);
+    }
+    photon::thread_sleep(-1);
+}
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