Record pthread routine address in clone(), keep helper threads on caller CPU core (workaround for Fugaku)

Change-Id: I29d1589e430dc1396558cdf3df4d068c27173612

executer/user/libsched_yield.c

@@ -1,6 +1,7 @@
 #define _GNU_SOURCE
 #include <dlfcn.h>
 #include <sys/time.h>
+#include <sys/syscall.h>
 #include <sched.h>
 #include <unistd.h>
 #include <stdlib.h>
@@ -27,3 +28,110 @@ int sched_yield(void)
 
 	return 0;
 }
+
+#undef pthread_create
+
+typedef int (*__pthread_create_fn)(pthread_t *thread,
+		const pthread_attr_t *attr,
+		void *(*start_routine) (void *),
+		void *arg);
+
+static __pthread_create_fn orig_pthread_create = 0;
+
+
+int pthread_create(pthread_t *thread,
+		const pthread_attr_t *attr,
+		void *(*start_routine) (void *),
+		void *arg)
+{
+	if (!orig_pthread_create) {
+		orig_pthread_create =
+			(__pthread_create_fn)dlsym(RTLD_NEXT, "pthread_create");
+	}
+
+	/* CLONE_VM and newsp == parent_tidptr impiles pthread start routine addr */
+	syscall(__NR_clone, CLONE_VM, start_routine, start_routine, 0, 0, 0);
+
+	return orig_pthread_create(thread, attr, start_routine, arg);
+}
+
+#if 0
+#define PROCMAPS_MAX_LEN	131072
+
+char *addr_to_lib(void *addr, unsigned long *offset_in_lib)
+{
+	char maps_path[PATH_MAX];
+	char buf[PROCMAPS_MAX_LEN];
+	int fd;
+	void *start, *end;
+	char perms[4];
+	unsigned long offset;
+	unsigned long dev[2];
+	int inode;
+	char path[PATH_MAX];
+	char *line;
+
+	sprintf(maps_path,"/proc/self/maps");
+	fd = open(maps_path, O_RDONLY);
+	if (fd < 0) {
+		fprintf(stderr,"error: cannot open the memory maps, %s\n",
+				strerror(errno));
+		return NULL;
+	}
+
+	memset(buf, 0, PROCMAPS_MAX_LEN);
+	read(fd, buf, PROCMAPS_MAX_LEN);
+	line = strtok(buf, "\n");
+	while (line) {
+		memset(path, 0, sizeof(path));
+		sscanf(line, "%012lx-%012lx %4s %lx %lx:%lx %d\t\t\t%[^\n]",
+			&start, &end, perms, &offset, &dev[0], &dev[1], &inode, path);
+
+		if (start <= addr && end > addr) {
+			close(fd);
+			if (offset_in_lib)
+				*offset_in_lib = (unsigned long)(addr - start);
+			return strlen(path) > 0 ? strdup(path) : NULL;
+		}
+
+		line = strtok(NULL, "\n");
+	}
+
+	close(fd);
+	return NULL;
+}
+
+int pthread_create(pthread_t *thread,
+		const pthread_attr_t *attr,
+		void *(*start_routine) (void *),
+		void *arg)
+{
+	char *lib = NULL;
+	int util_thread = 1;
+	unsigned long offset;
+
+	if (!orig_pthread_create) {
+		orig_pthread_create =
+			(__pthread_create_fn)dlsym(RTLD_NEXT, "pthread_create");
+	}
+
+	lib = addr_to_lib(start_routine, &offset);
+	if (lib)
+		printf("%s: 0x%lx is in %s @ 0x%lx\n",
+				__func__, start_routine, lib, offset);
+
+	if (lib && (strstr(lib, "iomp") || strstr(lib, "psm"))) {
+		util_thread = 0;
+	}
+
+	if (util_thread) {
+		/* McKernel util_indicate_clone() */
+		syscall(731);
+	}
+
+	if (lib)
+		free(lib);
+
+	return orig_pthread_create(thread, attr, start_routine, arg);
+}
+#endif