Merge \"sched_policy: Add support for /proc/<tid>/timerslack_ns over PR_SET_TIMERSLACK_PID\" (acf5e849) · Commits · e / os / android_system_core

libcutils/sched_policy.c

+25 −5

Original line number	Diff line number	Diff line
		@@ -166,7 +166,7 @@ static int getCGroupSubsys(int tid, const char* subsys, char* buf, size_t bufLen
		FILE *fp;

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

		@@ -323,6 +323,27 @@ int set_cpuset_policy(int tid, SchedPolicy policy)
		#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)
		{
		if (tid == 0) {
		@@ -335,12 +356,11 @@ int set_sched_policy(int tid, SchedPolicy policy)
		char statfile[64];
		char statline[1024];
		char thread_name[255];
		int fd;

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

		fd = open(statfile, O_RDONLY);
		int fd = open(statfile, O_RDONLY \| O_CLOEXEC);
		if (fd >= 0) {
		int rc = read(fd, statline, 1023);
		close(fd);
		@@ -405,8 +425,8 @@ int set_sched_policy(int tid, SchedPolicy policy)
		&param);
		}

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

		return 0;
		}