#endif
#endif /* USE_LIBCRYPT */
+#include <dirent.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
}
}
+#if defined(__linux__) && defined USE_CPU_AFFINITY
+/* filter directory name of the pattern node<X> */
+static int numa_filter(const struct dirent *dir)
+{
+ char *endptr;
+
+ /* dir name must start with "node" prefix */
+ if (strncmp(dir->d_name, "node", 4))
+ return 0;
+
+ /* dir name must be at least 5 characters long */
+ if (!dir->d_name[4])
+ return 0;
+
+ /* dir name must end with a numeric id */
+ if (strtol(&dir->d_name[4], &endptr, 10) < 0 || *endptr)
+ return 0;
+
+ /* all tests succeeded */
+ return 1;
+}
+
+/* Parse a linux cpu map string representing to a numeric cpu mask map
+ * The cpu map string is a list of 4-byte hex strings separated by commas, with
+ * most-significant byte first, one bit per cpu number.
+ */
+static void parse_cpumap(char *cpumap_str, struct hap_cpuset *cpu_set)
+{
+ unsigned long cpumap;
+ char *start, *endptr, *comma;
+ int i, j;
+
+ ha_cpuset_zero(cpu_set);
+
+ i = 0;
+ do {
+ /* reverse-search for a comma, parse the string after the comma
+ * or at the beginning if no comma found
+ */
+ comma = strrchr(cpumap_str, ',');
+ start = comma ? comma + 1 : cpumap_str;
+
+ cpumap = strtoul(start, &endptr, 16);
+ for (j = 0; cpumap; cpumap >>= 1, ++j) {
+ if (cpumap & 0x1)
+ ha_cpuset_set(cpu_set, j + i * 32);
+ }
+
+ if (comma)
+ *comma = '\0';
+ ++i;
+ } while (comma);
+}
+
+/* Read the first line of a file from <path> into the trash buffer.
+ * Returns 0 on success, otherwise non-zero.
+ */
+static int read_file_to_trash(const char *path)
+{
+ FILE *file;
+ int ret = 1;
+
+ file = fopen(path, "r");
+ if (file) {
+ if (fgets(trash.area, trash.size, file))
+ ret = 0;
+
+ fclose(file);
+ }
+
+ return ret;
+}
+
+/* Inspect the cpu topology of the machine on startup. If a multi-socket
+ * machine is detected, try to bind on the first node with active cpu. This is
+ * done to prevent an impact on the overall performance when the topology of
+ * the machine is unknown. This function is not called if one of the conditions
+ * is met :
+ * - a non-null nbthread directive is active
+ * - a restrictive cpu-map directive is active
+ * - a restrictive affinity is already applied, for example via taskset
+ *
+ * Returns the count of cpus selected. If no automatic binding was required or
+ * an error occurred and the topology is unknown, 0 is returned.
+ */
+static int numa_detect_topology()
+{
+ struct dirent **node_dirlist;
+ int node_dirlist_size;
+
+ struct hap_cpuset active_cpus, node_cpu_set;
+ const char *parse_cpu_set_args[2];
+ char cpumap_path[PATH_MAX];
+ char *err = NULL;
+
+ /* node_cpu_set count is used as return value */
+ ha_cpuset_zero(&node_cpu_set);
+
+ /* 1. count the sysfs node<X> directories */
+ node_dirlist_size = scandir(NUMA_DETECT_SYSTEM_SYSFS_PATH"/node", &node_dirlist, numa_filter, alphasort);
+ if (node_dirlist_size <= 1)
+ goto free_scandir_entries;
+
+ /* 2. read and parse the list of currently online cpu */
+ if (read_file_to_trash(NUMA_DETECT_SYSTEM_SYSFS_PATH"/cpu/online")) {
+ ha_notice("Cannot read online CPUs list, will not try to refine binding\n");
+ goto free_scandir_entries;
+ }
+
+ parse_cpu_set_args[0] = trash.area;
+ parse_cpu_set_args[1] = "\0";
+ if (parse_cpu_set(parse_cpu_set_args, &active_cpus, 1, &err)) {
+ ha_notice("Cannot read online CPUs list: '%s'. Will not try to refine binding\n", err);
+ free(err);
+ goto free_scandir_entries;
+ }
+
+ /* 3. loop through nodes dirs and find the first one with active cpus */
+ while (node_dirlist_size--) {
+ const char *node = node_dirlist[node_dirlist_size]->d_name;
+ ha_cpuset_zero(&node_cpu_set);
+
+ snprintf(cpumap_path, PATH_MAX, "%s/node/%s/cpumap",
+ NUMA_DETECT_SYSTEM_SYSFS_PATH, node);
+
+ if (read_file_to_trash(cpumap_path)) {
+ ha_notice("Cannot read CPUs list of '%s', will not select them to refine binding\n", node);
+ free(node_dirlist[node_dirlist_size]);
+ continue;
+ }
+
+ parse_cpumap(trash.area, &node_cpu_set);
+ ha_cpuset_and(&node_cpu_set, &active_cpus);
+
+ /* 5. set affinity on the first found node with active cpus */
+ if (!ha_cpuset_count(&node_cpu_set)) {
+ free(node_dirlist[node_dirlist_size]);
+ continue;
+ }
+
+ ha_diag_warning("Multi-socket cpu detected, automatically binding on active CPUs of '%s' (%u active cpu(s))\n", node, ha_cpuset_count(&node_cpu_set));
+ if (sched_setaffinity(getpid(), sizeof(node_cpu_set.cpuset), &node_cpu_set.cpuset) == -1) {
+ ha_warning("Cannot set the cpu affinity for this multi-cpu machine\n");
+
+ /* clear the cpuset used as return value */
+ ha_cpuset_zero(&node_cpu_set);
+ }
+
+ free(node_dirlist[node_dirlist_size]);
+ break;
+ }
+
+ free_scandir_entries:
+ while (node_dirlist_size-- > 0)
+ free(node_dirlist[node_dirlist_size]);
+ free(node_dirlist);
+
+ return ha_cpuset_count(&node_cpu_set);
+}
+#endif /* __linux__ && USE_CPU_AFFINITY */
+
/*
* Returns the error code, 0 if OK, or any combination of :
* - ERR_ABORT: must abort ASAP
* allows to easily control the number of threads using taskset.
*/
global.nbthread = 1;
+
#if defined(USE_THREAD)
- if (global.nbproc == 1)
- global.nbthread = thread_cpus_enabled_at_boot;
+ if (global.nbproc == 1) {
+ int numa_cores = 0;
+#if defined(__linux__) && defined USE_CPU_AFFINITY
+ if (!thread_cpu_mask_forced())
+ numa_cores = numa_detect_topology();
+#endif
+ global.nbthread = numa_cores ? numa_cores :
+ thread_cpus_enabled_at_boot;
+ }
all_threads_mask = nbits(global.nbthread);
#endif
}
projects / thirdparty / haproxy.git / commitdiff
