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Linux + x86_64 optimisations.

Add likely() macro.
Optimise a few obvious code paths with likely/unlikely.
Change algo to sse2_amd64 by default.
Move priority change to worker threads only.
Detect number of CPUs and set default number of threads == CPUs.
Add scheduling policy change to worker threads to SCHED_IDLE first and fallback to SCHED_BATCH on linux.
Don't error when failing to set priority.
Add CPU affinity and bind worker threads to CPUs when number of threads is a multiple of number of CPUs.
Update NEWS with changes.
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1 parent f2e4ff0 commit 8a832eeab524bbad160adb7c27acb370d6adedff @ckolivas ckolivas committed
Showing with 83 additions and 30 deletions.
  1. +6 −0 NEWS
  2. +67 −22 cpu-miner.c
  3. +5 −3 miner.h
  4. +5 −5 sha256_sse2_amd64.c
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6 NEWS
@@ -1,3 +1,9 @@
+- Linux x86_64 optimisations - Con Kolivas
+- Optimise for x86_64 by default by using sse2_64 algo
+- Detects CPUs and sets number of threads accordingly
+- Uses CPU affinity for each thread where appropriate
+- Sets scheduling policy to lowest possible
+- Minor performance tweaks
Version 1.0.1 - May 14, 2011
View
89 cpu-miner.c
@@ -9,6 +9,7 @@
*/
#include "cpuminer-config.h"
+#define _GNU_SOURCE
#include <stdio.h>
#include <stdlib.h>
@@ -33,6 +34,35 @@
#define DEF_RPC_PASSWORD "rpcpass"
#define DEF_RPC_USERPASS DEF_RPC_USERNAME ":" DEF_RPC_PASSWORD
+#ifdef __linux /* Linux specific policy and affinity management */
+#include <sched.h>
+static inline void drop_policy(void)
+{
+ struct sched_param param;
+
+ if (unlikely(sched_setscheduler(0, SCHED_IDLE, &param) == -1))
+ sched_setscheduler(0, SCHED_BATCH, &param);
+}
+
+static inline void affine_to_cpu(int id, int cpu)
+{
+ cpu_set_t set;
+
+ CPU_ZERO(&set);
+ CPU_SET(cpu, &set);
+ sched_setaffinity(0, sizeof(&set), &set);
+ applog(LOG_INFO, "Binding thread %d to cpu %d", id, cpu);
+}
+#else
+static inline void drop_policy(void)
+{
+}
+
+static inline void affine_to_cpu(int id, int cpu)
+{
+}
+#endif
+
enum workio_commands {
WC_GET_WORK,
WC_SUBMIT_WORK,
@@ -83,8 +113,13 @@ static int opt_fail_pause = 30;
int opt_scantime = 5;
static json_t *opt_config;
static const bool opt_time = true;
+#ifdef WANT_X8664_SSE2
+static enum sha256_algos opt_algo = ALGO_SSE2_64;
+#else
static enum sha256_algos opt_algo = ALGO_C;
-static int opt_n_threads = 1;
+#endif
+static int opt_n_threads;
+static int num_processors;
static char *rpc_url;
static char *rpc_userpass;
static char *rpc_user, *rpc_pass;
@@ -214,12 +249,12 @@ static bool jobj_binary(const json_t *obj, const char *key,
json_t *tmp;
tmp = json_object_get(obj, key);
- if (!tmp) {
+ if (unlikely(!tmp)) {
applog(LOG_ERR, "JSON key '%s' not found", key);
return false;
}
hexstr = json_string_value(tmp);
- if (!hexstr) {
+ if (unlikely(!hexstr)) {
applog(LOG_ERR, "JSON key '%s' is not a string", key);
return false;
}
@@ -231,23 +266,23 @@ static bool jobj_binary(const json_t *obj, const char *key,
static bool work_decode(const json_t *val, struct work *work)
{
- if (!jobj_binary(val, "midstate",
- work->midstate, sizeof(work->midstate))) {
+ if (unlikely(!jobj_binary(val, "midstate",
+ work->midstate, sizeof(work->midstate)))) {
applog(LOG_ERR, "JSON inval midstate");
goto err_out;
}
- if (!jobj_binary(val, "data", work->data, sizeof(work->data))) {
+ if (unlikely(!jobj_binary(val, "data", work->data, sizeof(work->data)))) {
applog(LOG_ERR, "JSON inval data");
goto err_out;
}
- if (!jobj_binary(val, "hash1", work->hash1, sizeof(work->hash1))) {
+ if (unlikely(!jobj_binary(val, "hash1", work->hash1, sizeof(work->hash1)))) {
applog(LOG_ERR, "JSON inval hash1");
goto err_out;
}
- if (!jobj_binary(val, "target", work->target, sizeof(work->target))) {
+ if (unlikely(!jobj_binary(val, "target", work->target, sizeof(work->target)))) {
applog(LOG_ERR, "JSON inval target");
goto err_out;
}
@@ -269,7 +304,7 @@ static bool submit_upstream_work(CURL *curl, const struct work *work)
/* build hex string */
hexstr = bin2hex(work->data, sizeof(work->data));
- if (!hexstr) {
+ if (unlikely(!hexstr)) {
applog(LOG_ERR, "submit_upstream_work OOM");
goto out;
}
@@ -284,7 +319,7 @@ static bool submit_upstream_work(CURL *curl, const struct work *work)
/* issue JSON-RPC request */
val = json_rpc_call(curl, rpc_url, rpc_userpass, s, false, false);
- if (!val) {
+ if (unlikely(!val)) {
applog(LOG_ERR, "submit_upstream_work json_rpc_call failed");
goto out;
}
@@ -351,7 +386,7 @@ static bool workio_get_work(struct workio_cmd *wc, CURL *curl)
/* obtain new work from bitcoin via JSON-RPC */
while (!get_upstream_work(curl, ret_work)) {
- if ((opt_retries >= 0) && (++failures > opt_retries)) {
+ if (unlikely((opt_retries >= 0) && (++failures > opt_retries))) {
applog(LOG_ERR, "json_rpc_call failed, terminating workio thread");
free(ret_work);
return false;
@@ -376,7 +411,7 @@ static bool workio_submit_work(struct workio_cmd *wc, CURL *curl)
/* submit solution to bitcoin via JSON-RPC */
while (!submit_upstream_work(curl, wc->u.work)) {
- if ((opt_retries >= 0) && (++failures > opt_retries)) {
+ if (unlikely((opt_retries >= 0) && (++failures > opt_retries))) {
applog(LOG_ERR, "...terminating workio thread");
return false;
}
@@ -397,7 +432,7 @@ static void *workio_thread(void *userdata)
bool ok = true;
curl = curl_easy_init();
- if (!curl) {
+ if (unlikely(!curl)) {
applog(LOG_ERR, "CURL initialization failed");
return NULL;
}
@@ -514,6 +549,17 @@ static void *miner_thread(void *userdata)
int thr_id = mythr->id;
uint32_t max_nonce = 0xffffff;
+ /* Set worker threads to nice 19 and then preferentially to SCHED_IDLE
+ * and if that fails, then SCHED_BATCH. No need for this to be an
+ * error if it fails */
+ setpriority(PRIO_PROCESS, 0, 19);
+ drop_policy();
+
+ /* Cpu affinity only makes sense if the number of threads is a multiple
+ * of the number of CPUs */
+ if (!(opt_n_threads % num_processors))
+ affine_to_cpu(mythr->id, mythr->id % num_processors);
+
while (1) {
struct work work __attribute__((aligned(128)));
unsigned long hashes_done;
@@ -522,7 +568,7 @@ static void *miner_thread(void *userdata)
bool rc;
/* obtain new work from internal workio thread */
- if (!get_work(mythr, &work)) {
+ if (unlikely(!get_work(mythr, &work))) {
applog(LOG_ERR, "work retrieval failed, exiting "
"mining thread %d", mythr->id);
goto out;
@@ -658,7 +704,7 @@ static void *longpoll_thread(void *userdata)
applog(LOG_INFO, "Long-polling activated for %s", lp_url);
curl = curl_easy_init();
- if (!curl) {
+ if (unlikely(!curl)) {
applog(LOG_ERR, "CURL initialization failed");
goto out;
}
@@ -668,7 +714,7 @@ static void *longpoll_thread(void *userdata)
val = json_rpc_call(curl, lp_url, rpc_userpass, rpc_req,
false, true);
- if (val) {
+ if (likely(val)) {
failures = 0;
json_decref(val);
@@ -809,6 +855,9 @@ static void parse_arg (int key, char *arg)
default:
show_usage();
}
+ num_processors = sysconf(_SC_NPROCESSORS_ONLN);
+ if (!opt_n_threads)
+ opt_n_threads = num_processors;
}
static void parse_config(void)
@@ -886,10 +935,6 @@ int main (int argc, char *argv[])
openlog("cpuminer", LOG_PID, LOG_USER);
#endif
- /* set our priority to the highest (aka "nicest, least intrusive") */
- if (setpriority(PRIO_PROCESS, 0, 19))
- perror("setpriority");
-
work_restart = calloc(opt_n_threads, sizeof(*work_restart));
if (!work_restart)
return 1;
@@ -922,7 +967,7 @@ int main (int argc, char *argv[])
return 1;
/* start longpoll thread */
- if (pthread_create(&thr->pth, NULL, longpoll_thread, thr)) {
+ if (unlikely(pthread_create(&thr->pth, NULL, longpoll_thread, thr))) {
applog(LOG_ERR, "longpoll thread create failed");
return 1;
}
@@ -938,7 +983,7 @@ int main (int argc, char *argv[])
if (!thr->q)
return 1;
- if (pthread_create(&thr->pth, NULL, miner_thread, thr)) {
+ if (unlikely(pthread_create(&thr->pth, NULL, miner_thread, thr))) {
applog(LOG_ERR, "thread %d create failed", i);
return 1;
}
View
8 miner.h
@@ -87,12 +87,14 @@ enum {
};
#endif
-#if defined(__GNUC__) && (__GNUC__ > 2) && defined(__OPTIMIZE__)
#undef unlikely
-#define unlikely(expr) (__builtin_expect((expr), 0))
+#undef likely
+#if defined(__GNUC__) && (__GNUC__ > 2) && defined(__OPTIMIZE__)
+#define unlikely(expr) (__builtin_expect(!!(expr), 0))
+#define likely(expr) (__builtin_expect(!!(expr), 1))
#else
-#undef unlikely
#define unlikely(expr) (expr)
+#define likely(expr) (expr)
#endif
#if defined(__i386__)
View
10 sha256_sse2_amd64.c
@@ -100,13 +100,13 @@ int scanhash_sse2_64(int thr_id, const unsigned char *pmidstate,
for (j = 0; j < 4; j++) {
mi.m = m_4hash[7];
- if (mi.i[j] == 0)
+ if (unlikely(mi.i[j] == 0))
break;
}
/* If j = true, we found a hit...so check it */
/* Use the C version for a check... */
- if (j != 4) {
+ if (unlikely(j != 4)) {
for (i = 0; i < 8; i++) {
mi.m = m_4hash[i];
*(uint32_t *)&(phash)[i*4] = mi.i[j];
@@ -121,12 +121,12 @@ int scanhash_sse2_64(int thr_id, const unsigned char *pmidstate,
nonce += 4;
- if ((nonce >= max_nonce) || work_restart[thr_id].restart)
+ if (unlikely((nonce >= max_nonce) || work_restart[thr_id].restart))
{
*nHashesDone = nonce;
return -1;
- }
- }
+ }
+ }
}
#endif /* WANT_X8664_SSE2 */

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