Merge "sched_policy: Add support for /proc/<tid>/timerslack_ns over PR_SET_TIMERSLACK_PID" (817d5349) · Commits · e / os / android_system_core

libcutils/sched_policy.c

+25 −5

Original line number	Original line	Diff line number	Diff line
	@@ -160,7 +160,7 @@ static int getSchedulerGroup(int tid, char* buf, size_t bufLen)
	FILE *fp;		FILE *fp;

	snprintf(pathBuf, sizeof(pathBuf), "/proc/%d/cgroup", tid);		snprintf(pathBuf, sizeof(pathBuf), "/proc/%d/cgroup", tid);
	if (!(fp = fopen(pathBuf, "r"))) {		if (!(fp = fopen(pathBuf, "re"))) {
	return -1;		return -1;
	}		}

	@@ -292,6 +292,27 @@ int set_cpuset_policy(int tid, SchedPolicy policy)
	#endif		#endif
	}		}

			static void set_timerslack_ns(int tid, unsigned long long slack) {
			char buf[64];

			/* v4.6+ kernels support the /proc/<tid>/timerslack_ns interface. */
			snprintf(buf, sizeof(buf), "/proc/%d/timerslack_ns", tid);
			int fd = open(buf, O_WRONLY \| O_CLOEXEC);
			if (fd != -1) {
			int len = snprintf(buf, sizeof(buf), "%llu", slack);
			if (write(fd, buf, len) != len) {
			SLOGE("set_timerslack_ns write failed: %s\n", strerror(errno));
			}
			close(fd);
			return;
			}

			/* If the above fails, try the old common.git PR_SET_TIMERSLACK_PID. */
			if (prctl(PR_SET_TIMERSLACK_PID, slack, tid) == -1) {
			SLOGE("set_timerslack_ns prctl failed: %s\n", strerror(errno));
			}
			}

	int set_sched_policy(int tid, SchedPolicy policy)		int set_sched_policy(int tid, SchedPolicy policy)
	{		{
	if (tid == 0) {		if (tid == 0) {
	@@ -304,12 +325,11 @@ int set_sched_policy(int tid, SchedPolicy policy)
	char statfile[64];		char statfile[64];
	char statline[1024];		char statline[1024];
	char thread_name[255];		char thread_name[255];
	int fd;

	snprintf(statfile, sizeof(statfile), "/proc/%d/stat", tid);		snprintf(statfile, sizeof(statfile), "/proc/%d/stat", tid);
	memset(thread_name, 0, sizeof(thread_name));		memset(thread_name, 0, sizeof(thread_name));

	fd = open(statfile, O_RDONLY);		int fd = open(statfile, O_RDONLY \| O_CLOEXEC);
	if (fd >= 0) {		if (fd >= 0) {
	int rc = read(fd, statline, 1023);		int rc = read(fd, statline, 1023);
	close(fd);		close(fd);
	@@ -372,8 +392,8 @@ int set_sched_policy(int tid, SchedPolicy policy)
	&param);		&param);
	}		}

	prctl(PR_SET_TIMERSLACK_PID,		set_timerslack_ns(tid, policy == SP_BACKGROUND ?
	policy == SP_BACKGROUND ? TIMER_SLACK_BG : TIMER_SLACK_FG, tid);		TIMER_SLACK_BG : TIMER_SLACK_FG);

	return 0;		return 0;
	}		}