Support setcpuaffinity on linux/bsd

Currently, there are several types of threads/child processes of a
redis server. Sometimes we need deeply optimise the performance of
redis, so we would like to isolate threads/processes.

There were some discussion about cpu affinity cases in the issue:
#2863

So implement cpu affinity setting by redis.conf in this patch, then
we can config server_cpulist/bio_cpulist/aof_rewrite_cpulist/
bgsave_cpulist by cpu list.

Examples of cpulist in redis.conf:
server_cpulist 0-7:2      means cpu affinity 0,2,4,6
bio_cpulist 1,3           means cpu affinity 1,3
aof_rewrite_cpulist 8-11  means cpu affinity 8,9,10,11
bgsave_cpulist 1,10-11    means cpu affinity 1,10,11

Test on linux/freebsd, both work fine.

Signed-off-by: zhenwei pi <pizhenwei@bytedance.com>

redis.conf

@@ -1780,3 +1780,18 @@ rdb-save-incremental-fsync yes
 # Maximum number of set/hash/zset/list fields that will be processed from
 # the main dictionary scan
 # active-defrag-max-scan-fields 1000
+
+# Redis server/IO threads, bio threads, aof rewrite child process, and bgsave
+# child process cpu affinity list config. syntax of cpu list looks like taskset
+# command. serveral examples:
+# set redis server/io threads to cpu affinity 0,2,4,6
+# server_cpulist 0-7:2
+#
+# set bio threads to cpu affinity 1,3
+# bio_cpulist 1,3
+#
+# set aof rewrite child process to cpu affinity 8,9,10,11
+# aof_rewrite_cpulist 8-11
+#
+# set bgsave child process to cpu affinity 1,10,11
+# bgsave_cpulist 1,10-11

src/Makefile

@@ -206,7 +206,7 @@ endif
 
 REDIS_SERVER_NAME=redis-server
 REDIS_SENTINEL_NAME=redis-sentinel
-REDIS_SERVER_OBJ=adlist.o quicklist.o ae.o anet.o dict.o server.o sds.o zmalloc.o lzf_c.o lzf_d.o pqsort.o zipmap.o sha1.o ziplist.o release.o networking.o util.o object.o db.o replication.o rdb.o t_string.o t_list.o t_set.o t_zset.o t_hash.o config.o aof.o pubsub.o multi.o debug.o sort.o intset.o syncio.o cluster.o crc16.o endianconv.o slowlog.o scripting.o bio.o rio.o rand.o memtest.o crcspeed.o crc64.o bitops.o sentinel.o notify.o setproctitle.o blocked.o hyperloglog.o latency.o sparkline.o redis-check-rdb.o redis-check-aof.o geo.o lazyfree.o module.o evict.o expire.o geohash.o geohash_helper.o childinfo.o defrag.o siphash.o rax.o t_stream.o listpack.o localtime.o lolwut.o lolwut5.o lolwut6.o acl.o gopher.o tracking.o connection.o tls.o sha256.o timeout.o
+REDIS_SERVER_OBJ=adlist.o quicklist.o ae.o anet.o dict.o server.o sds.o zmalloc.o lzf_c.o lzf_d.o pqsort.o zipmap.o sha1.o ziplist.o release.o networking.o util.o object.o db.o replication.o rdb.o t_string.o t_list.o t_set.o t_zset.o t_hash.o config.o aof.o pubsub.o multi.o debug.o sort.o intset.o syncio.o cluster.o crc16.o endianconv.o slowlog.o scripting.o bio.o rio.o rand.o memtest.o crcspeed.o crc64.o bitops.o sentinel.o notify.o setproctitle.o blocked.o hyperloglog.o latency.o sparkline.o redis-check-rdb.o redis-check-aof.o geo.o lazyfree.o module.o evict.o expire.o geohash.o geohash_helper.o childinfo.o defrag.o siphash.o rax.o t_stream.o listpack.o localtime.o lolwut.o lolwut5.o lolwut6.o acl.o gopher.o tracking.o connection.o tls.o sha256.o timeout.o setcpuaffinity.o
 REDIS_CLI_NAME=redis-cli
 REDIS_CLI_OBJ=anet.o adlist.o dict.o redis-cli.o zmalloc.o release.o ae.o crcspeed.o crc64.o siphash.o crc16.o
 REDIS_BENCHMARK_NAME=redis-benchmark

src/aof.c

@@ -1596,6 +1596,7 @@ int rewriteAppendOnlyFileBackground(void) {
 
         /* Child */
         redisSetProcTitle("redis-aof-rewrite");
+        redisSetCpuAffinity(server.aof_rewrite_cpulist);
         snprintf(tmpfile,256,"temp-rewriteaof-bg-%d.aof", (int) getpid());
         if (rewriteAppendOnlyFile(tmpfile) == C_OK) {
             sendChildCOWInfo(CHILD_INFO_TYPE_AOF, "AOF rewrite");

src/bio.c

@@ -166,6 +166,8 @@ void *bioProcessBackgroundJobs(void *arg) {
         break;
     }
 
+    redisSetCpuAffinity(server.bio_cpulist);
+
     /* Make the thread killable at any time, so that bioKillThreads()
      * can work reliably. */
     pthread_setcancelstate(PTHREAD_CANCEL_ENABLE, NULL);

src/config.c

@@ -2133,6 +2133,10 @@ standardConfig configs[] = {
     createStringConfig("syslog-ident", NULL, IMMUTABLE_CONFIG, ALLOW_EMPTY_STRING, server.syslog_ident, "redis", NULL, NULL),
     createStringConfig("dbfilename", NULL, MODIFIABLE_CONFIG, ALLOW_EMPTY_STRING, server.rdb_filename, "dump.rdb", isValidDBfilename, NULL),
     createStringConfig("appendfilename", NULL, IMMUTABLE_CONFIG, ALLOW_EMPTY_STRING, server.aof_filename, "appendonly.aof", isValidAOFfilename, NULL),
+    createStringConfig("server_cpulist", NULL, IMMUTABLE_CONFIG, EMPTY_STRING_IS_NULL, server.server_cpulist, NULL, NULL, NULL),
+    createStringConfig("bio_cpulist", NULL, IMMUTABLE_CONFIG, EMPTY_STRING_IS_NULL, server.bio_cpulist, NULL, NULL, NULL),
+    createStringConfig("aof_rewrite_cpulist", NULL, IMMUTABLE_CONFIG, EMPTY_STRING_IS_NULL, server.aof_rewrite_cpulist, NULL, NULL, NULL),
+    createStringConfig("bgsave_cpulist", NULL, IMMUTABLE_CONFIG, EMPTY_STRING_IS_NULL, server.bgsave_cpulist, NULL, NULL, NULL),
 
     /* Enum Configs */
     createEnumConfig("supervised", NULL, IMMUTABLE_CONFIG, supervised_mode_enum, server.supervised_mode, SUPERVISED_NONE, NULL, NULL),

src/config.h

@@ -244,4 +244,10 @@ int pthread_setname_np(const char *name);
 #endif
 #endif
 
+/* Check if we can use setcpuaffinity(). */
+#if (defined __linux || defined __NetBSD__ || defined __FreeBSD__ || defined __OpenBSD__)
+#define USE_SETCPUAFFINITY
+void setcpuaffinity(const char *cpulist);
+#endif
+
 #endif

src/networking.c

@@ -2843,6 +2843,7 @@ void *IOThreadMain(void *myid) {
 
     snprintf(thdname, sizeof(thdname), "io_thd_%ld", id);
     redis_set_thread_title(thdname);
+    redisSetCpuAffinity(server.server_cpulist);
 
     while(1) {
         /* Wait for start */

src/rdb.c

@@ -1351,6 +1351,7 @@ int rdbSaveBackground(char *filename, rdbSaveInfo *rsi) {
 
         /* Child */
         redisSetProcTitle("redis-rdb-bgsave");
+        redisSetCpuAffinity(server.bgsave_cpulist);
         retval = rdbSave(filename,rsi);
         if (retval == C_OK) {
             sendChildCOWInfo(CHILD_INFO_TYPE_RDB, "RDB");
@@ -2458,6 +2459,7 @@ int rdbSaveToSlavesSockets(rdbSaveInfo *rsi) {
         rioInitWithFd(&rdb,server.rdb_pipe_write);
 
         redisSetProcTitle("redis-rdb-to-slaves");
+        redisSetCpuAffinity(server.bgsave_cpulist);
 
         retval = rdbSaveRioWithEOFMark(&rdb,NULL,rsi);
         if (retval == C_OK && rioFlush(&rdb) == 0)

src/server.c

@@ -4850,6 +4850,14 @@ void redisSetProcTitle(char *title) {
 #endif
 }
 
+void redisSetCpuAffinity(const char *cpulist) {
+#ifdef USE_SETCPUAFFINITY
+    setcpuaffinity(cpulist);
+#else
+    UNUSED(cpulist);
+#endif
+}
+
 /*
  * Check whether systemd or upstart have been used to start redis.
  */
@@ -5118,6 +5126,7 @@ int main(int argc, char **argv) {
         serverLog(LL_WARNING,"WARNING: You specified a maxmemory value that is less than 1MB (current value is %llu bytes). Are you sure this is what you really want?", server.maxmemory);
     }
 
+    redisSetCpuAffinity(server.server_cpulist);
     aeSetBeforeSleepProc(server.el,beforeSleep);
     aeSetAfterSleepProc(server.el,afterSleep);
     aeMain(server.el);

src/server.h

@@ -1433,6 +1433,11 @@ struct redisServer {
     int tls_replication;
     int tls_auth_clients;
     redisTLSContextConfig tls_ctx_config;
+    /* cpu affinity */
+    char *server_cpulist; /* cpu affinity list of redis server main/io thread. */
+    char *bio_cpulist; /* cpu affinity list of bio thread. */
+    char *aof_rewrite_cpulist; /* cpu affinity list of aof rewrite process. */
+    char *bgsave_cpulist; /* cpu affinity list of bgsave process. */
 };
 
 typedef struct pubsubPattern {
@@ -1585,6 +1590,7 @@ void exitFromChild(int retcode);
 size_t redisPopcount(void *s, long count);
 void redisSetProcTitle(char *title);
 int redisCommunicateSystemd(const char *sd_notify_msg);
+void redisSetCpuAffinity(const char *cpulist);
 
 /* networking.c -- Networking and Client related operations */
 client *createClient(connection *conn);

src/setcpuaffinity.c

@@ -0,0 +1,129 @@
+/* ==========================================================================
+ * setproctitle.c - Linux/BSD setcpuaffinity.
+ * --------------------------------------------------------------------------
+ * Copyright (C) 2020  zhenwei pi
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to permit
+ * persons to whom the Software is furnished to do so, subject to the
+ * following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included
+ * in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
+ * NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+ * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+ * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
+ * USE OR OTHER DEALINGS IN THE SOFTWARE.
+ * ==========================================================================
+ */
+#ifndef _GNU_SOURCE
+#define _GNU_SOURCE
+#endif
+#include <stdlib.h>
+#include <string.h>
+#include <ctype.h>
+#ifdef __linux__
+#include <sched.h>
+#endif
+#ifdef __FreeBSD__
+#include <sys/param.h>
+#include <sys/cpuset.h>
+#endif
+#include "config.h"
+
+#ifdef USE_SETCPUAFFINITY
+static const char *next_token(const char *q,  int sep) {
+    if (q)
+        q = strchr(q, sep);
+    if (q)
+        q++;
+
+    return q;
+}
+
+static int next_num(const char *str, char **end, int *result) {
+    if (!str || *str == '\0' || !isdigit(*str))
+        return -1;
+
+    *result = strtoul(str, end, 10);
+    if (str == *end)
+        return -1;
+
+    return 0;
+}
+
+/* set current thread cpu affinity to cpu list, this function works like
+ * taskset command (actually cpulist parsing logic reference to util-linux).
+ * example of this function: "0,2,3", "0,2-3", "0-20:2". */
+void setcpuaffinity(const char *cpulist) {
+    const char *p, *q;
+    char *end = NULL;
+#ifdef __linux__
+    cpu_set_t cpuset;
+#endif
+#ifdef __FreeBSD__
+    cpuset_t cpuset;
+#endif
+
+    if (!cpulist)
+        return;
+
+    CPU_ZERO(&cpuset);
+
+    q = cpulist;
+    while (p = q, q = next_token(q, ','), p) {
+        int a, b, s;
+        const char *c1, *c2;
+
+        if (next_num(p, &end, &a) != 0)
+            return;
+
+        b = a;
+        s = 1;
+        p = end;
+
+        c1 = next_token(p, '-');
+        c2 = next_token(p, ',');
+
+        if (c1 != NULL && (c2 == NULL || c1 < c2)) {
+            if (next_num(c1, &end, &b) != 0)
+                return;
+
+            c1 = end && *end ? next_token(end, ':') : NULL;
+            if (c1 != NULL && (c2 == NULL || c1 < c2)) {
+                if (next_num(c1, &end, &s) != 0)
+                    return;
+
+                if (s == 0)
+                    return;
+            }
+        }
+
+        if ((a > b))
+            return;
+
+        while (a <= b) {
+            CPU_SET(a, &cpuset);
+            a += s;
+        }
+    }
+
+    if (end && *end)
+        return;
+
+#ifdef __linux__
+    sched_setaffinity(0, sizeof(cpuset), &cpuset);
+#endif
+#ifdef __FreeBSD__
+    cpuset_setaffinity(CPU_LEVEL_WHICH, CPU_WHICH_TID, -1, sizeof(cpuset), &cpuset);
+#endif
+}
+
+#endif /* USE_SETCPUAFFINITY */

tests/unit/introspection.tcl

@@ -94,6 +94,10 @@ start_server {tags {"introspection"}} {
             slaveof
             bind
             requirepass
+            server_cpulist
+            bio_cpulist
+            aof_rewrite_cpulist
+            bgsave_cpulist
         }
 
         set configs {}