From 3b03c4b2bcbcf5a913a3127d2b45283540c505c3 Mon Sep 17 00:00:00 2001 From: Dimitri Staessens Date: Mon, 2 Apr 2018 08:19:54 +0200 Subject: ipcpd: Enable locking threads to a CPU core This adds a function that locks a thread to a random core. This greatly improves performance on multi-cpu systems. There is no portable way to do this, this only implements it for GNU/Linux. Signed-off-by: Dimitri Staessens Signed-off-by: Sander Vrijders --- src/ipcpd/ipcp.c | 29 +++++++++++++++++++++++++++++ 1 file changed, 29 insertions(+) (limited to 'src/ipcpd/ipcp.c') diff --git a/src/ipcpd/ipcp.c b/src/ipcpd/ipcp.c index d834997f..2321e2a8 100644 --- a/src/ipcpd/ipcp.c +++ b/src/ipcpd/ipcp.c @@ -20,6 +20,11 @@ * Foundation, Inc., http://www.fsf.org/about/contact/. */ +#if defined(__linux__) && !defined(DISABLE_CORE_LOCK) +#define _GNU_SOURCE +#define NPROC (sysconf(_SC_NPROCESSORS_ONLN)) +#endif + #define _POSIX_C_SOURCE 200112L #define __XSI_VISIBLE 500 @@ -42,6 +47,9 @@ #include #include #include +#if defined(__linux__) && !defined(DISABLE_CORE_LOCK) +#include +#endif struct cmd { struct list_head next; @@ -779,3 +787,24 @@ int ipcp_wait_state(enum ipcp_state state, return ret; } + +void ipcp_lock_to_core(void) +{ +#if defined(__linux__) && !defined(DISABLE_CORE_LOCK) + cpu_set_t cpus; + size_t cpu; + + /* Choose a random core. */ + cpu = rand() % NPROC; + + CPU_ZERO(&cpus); + CPU_SET(cpu, &cpus); + + if (pthread_setaffinity_np(pthread_self(), sizeof(cpus), &cpus)) + log_warn("Failed to lock thread %lu to CPU %lu/%lu.", + pthread_self(), cpu, NPROC); + else + log_dbg("Locked thread %lu to CPU %lu/%lu.", + pthread_self(), cpu, NPROC); +#endif +} -- cgit v1.2.3