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authorThomas White <taw@physics.org>2011-03-22 11:16:47 +0100
committerThomas White <taw@physics.org>2012-02-22 15:27:20 +0100
commiteaee0f6415b06f40ff7f477328f9f26f01c4d7ec (patch)
treea80d312a18dfdcee1716610c8faa6048a5a32ac8 /src/thread-pool.c
parent5b903bf7bbef684dbbaf27073a7a7e452e27a23f (diff)
Add thread affinity stuff
Diffstat (limited to 'src/thread-pool.c')
-rw-r--r--src/thread-pool.c65
1 files changed, 65 insertions, 0 deletions
diff --git a/src/thread-pool.c b/src/thread-pool.c
index 070e4fa0..d672062c 100644
--- a/src/thread-pool.c
+++ b/src/thread-pool.c
@@ -23,9 +23,63 @@
#include <pthread.h>
#include <assert.h>
+#ifdef HAVE_CPU_AFFINITY
+#include <sched.h>
+#endif
+
+
#include "utils.h"
+/* ------------------------------ CPU affinity ------------------------------ */
+
+#ifdef HAVE_CPU_AFFINITY
+
+static int next_cpu(int cur)
+{
+ cur++;
+
+ if ( cur == 73 ) cur = 0;
+
+ return cur;
+}
+
+
+static void set_affinity(int cpu)
+{
+ cpu_set_t c;
+
+ CPU_ZERO(&c);
+ CPU_SET(cpu, &c);
+ if ( sched_setaffinity(0, sizeof(cpu_set_t), &c) ) {
+
+ /* Cannot use ERROR() just yet */
+ fprintf(stderr, "Failed to set CPU affinity.\n");
+
+ } else {
+
+ fprintf(stderr, "Successfully set CPU affinity to %i\n", cpu);
+
+ }
+}
+
+#else /* HAVE_CPU_AFFINITY */
+
+static int next_cpu(int cur)
+{
+ return 0;
+}
+
+
+static void set_affinity(int cpu)
+{
+}
+
+#endif /* HAVE_CPU_AFFINITY */
+
+
+/* --------------------------- Status label stuff --------------------------- */
+
static int use_status_labels = 0;
static pthread_key_t status_label_key;
pthread_mutex_t stderr_lock = PTHREAD_MUTEX_INITIALIZER;
@@ -35,6 +89,7 @@ struct worker_args
struct task_queue_range *tqr;
struct task_queue *tq;
int id;
+ int cpu;
};
@@ -81,6 +136,8 @@ static void *range_worker(void *pargsv)
struct task_queue_range *q = w->tqr;
int *cookie;
+ set_affinity(w->cpu);
+
cookie = malloc(sizeof(int));
*cookie = w->id;
pthread_setspecific(status_label_key, cookie);
@@ -132,6 +189,7 @@ void run_thread_range(int n_tasks, int n_threads, const char *text,
{
pthread_t *workers;
int i;
+ int cpu = 0;
struct task_queue_range q;
/* The nation of CrystFEL prides itself on having 0% unemployment. */
@@ -166,6 +224,8 @@ void run_thread_range(int n_tasks, int n_threads, const char *text,
w->tqr = &q;
w->tq = NULL;
w->id = i;
+ w->cpu = cpu;
+ cpu = next_cpu(cpu);
if ( pthread_create(&workers[i], NULL, range_worker, w) ) {
/* Not ERROR() here */
@@ -211,6 +271,8 @@ static void *task_worker(void *pargsv)
struct task_queue *q = w->tq;
int *cookie;
+ set_affinity(w->cpu);
+
cookie = malloc(sizeof(int));
*cookie = w->id;
pthread_setspecific(status_label_key, cookie);
@@ -265,6 +327,7 @@ int run_threads(int n_threads, void (*work)(void *, int),
pthread_t *workers;
int i;
struct task_queue q;
+ int cpu = 0;
pthread_key_create(&status_label_key, NULL);
@@ -292,6 +355,8 @@ int run_threads(int n_threads, void (*work)(void *, int),
w->tq = &q;
w->tqr = NULL;
w->id = i;
+ w->cpu = cpu;
+ cpu = next_cpu(cpu);
if ( pthread_create(&workers[i], NULL, task_worker, w) ) {
/* Not ERROR() here */