Rework a bit the documentation for CPU pinning.

redis.conf

@@ -1781,17 +1781,27 @@ rdb-save-incremental-fsync yes
 # 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
+# It is possible to pin different threads and processes of Redis to specific
+# CPUs in your system, in order to maximize the performances of the server.
+# This is useful both in order to pin different Redis threads in different
+# CPUs, but also in order to make sure that multiple Redis instances running
+# in the same host will be pinned to different CPUs.
+#
+# Normally you can do this using the "taskset" command, however it is also
+# possible to this via Redis configuration directly, both in Linux and FreeBSD.
+#
+# You can pin the server/IO threads, bio threads, aof rewrite child process, and
+# the bgsave child process. The syntax to specify the cpu list is the same as
+# the taskset command:
+#
+# 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
+# Set bio threads to cpu affinity 1,3:
 # bio_cpulist 1,3
 #
-# set aof rewrite child process to cpu affinity 8,9,10,11
+# 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
+# Set bgsave child process to cpu affinity 1,10,11
 # bgsave_cpulist 1,10-11

src/setcpuaffinity.c

@@ -1,5 +1,5 @@
 /* ==========================================================================
- * setproctitle.c - Linux/BSD setcpuaffinity.
+ * setcpuaffinity.c - Linux/BSD setcpuaffinity.
  * --------------------------------------------------------------------------
  * Copyright (C) 2020  zhenwei pi
  *