am e5b0c837: Merge "add cpuset support to libcutils" into mnc-dev (63e38313) · Commits · e / os / android_system_core

include/cutils/sched_policy.h

+2 −0

Original line number	Diff line number	Diff line
		@@ -34,6 +34,8 @@ typedef enum {
		SP_SYSTEM_DEFAULT = SP_FOREGROUND,
		} SchedPolicy;

		extern int set_cpuset_policy(int tid, SchedPolicy policy);

		/* Assign thread tid to the cgroup associated with the specified policy.
		* If the thread is a thread group leader, that is it's gettid() == getpid(),
		* then the other threads in the same thread group are _not_ affected.

libcutils/Android.mk

+6 −0

Original line number	Diff line number	Diff line
		@@ -122,6 +122,9 @@ LOCAL_SRC_FILES_x86_64 += \

		LOCAL_C_INCLUDES := $(libcutils_c_includes)
		LOCAL_STATIC_LIBRARIES := liblog
		ifneq ($(ENABLE_CPUSETS),)
		LOCAL_CFLAGS += -DUSE_CPUSETS
		endif
		LOCAL_CFLAGS += -Werror -std=gnu90
		include $(BUILD_STATIC_LIBRARY)

		@@ -131,6 +134,9 @@ LOCAL_MODULE := libcutils
		# liblog symbols present in libcutils.
		LOCAL_WHOLE_STATIC_LIBRARIES := libcutils liblog
		LOCAL_SHARED_LIBRARIES := liblog
		ifneq ($(ENABLE_CPUSETS),)
		LOCAL_CFLAGS += -DUSE_CPUSETS
		endif
		LOCAL_CFLAGS += -Werror
		LOCAL_C_INCLUDES := $(libcutils_c_includes)
		include $(BUILD_SHARED_LIBRARY)

libcutils/sched_policy.c

+86 −31

Original line number	Diff line number	Diff line
		@@ -59,27 +59,16 @@ static int __sys_supports_schedgroups = -1;
		static int bg_cgroup_fd = -1;
		static int fg_cgroup_fd = -1;

		// File descriptors open to /dev/cpuset/../tasks, setup by initialize, or -1 on error
		static int bg_cpuset_fd = -1;
		static int fg_cpuset_fd = -1;

		/* Add tid to the scheduling group defined by the policy */
		static int add_tid_to_cgroup(int tid, SchedPolicy policy)
		static int add_tid_to_cgroup(int tid, int fd)
		{
		int fd;

		switch (policy) {
		case SP_BACKGROUND:
		fd = bg_cgroup_fd;
		break;
		case SP_FOREGROUND:
		case SP_AUDIO_APP:
		case SP_AUDIO_SYS:
		fd = fg_cgroup_fd;
		break;
		default:
		fd = -1;
		break;
		}

		if (fd < 0) {
		SLOGE("add_tid_to_cgroup failed; policy=%d\n", policy);
		SLOGE("add_tid_to_cgroup failed; fd=%d\n", fd);
		errno = EINVAL;
		return -1;
		}

		@@ -100,8 +89,9 @@ static int add_tid_to_cgroup(int tid, SchedPolicy policy)
		*/
		if (errno == ESRCH)
		return 0;
		SLOGW("add_tid_to_cgroup failed to write '%s' (%s); policy=%d\n",
		ptr, strerror(errno), policy);
		SLOGW("add_tid_to_cgroup failed to write '%s' (%s); fd=%d\n",
		ptr, strerror(errno), fd);
		errno = EINVAL;
		return -1;
		}

		@@ -127,6 +117,17 @@ static void __initialize(void) {
		} else {
		__sys_supports_schedgroups = 0;
		}

		#ifdef USE_CPUSETS
		if (!access("/dev/cpuset/tasks", F_OK)) {

		filename = "/dev/cpuset/foreground/tasks";
		fg_cpuset_fd = open(filename, O_WRONLY \| O_CLOEXEC);
		filename = "/dev/cpuset/background/tasks";
		bg_cpuset_fd = open(filename, O_WRONLY \| O_CLOEXEC);
		}
		#endif

		}

		/*
		@@ -236,6 +237,45 @@ int get_sched_policy(int tid, SchedPolicy *policy)
		return 0;
		}

		int set_cpuset_policy(int tid, SchedPolicy policy)
		{
		// in the absence of cpusets, use the old sched policy
		#ifndef USE_CPUSETS
		return set_sched_policy(tid, policy);
		#else
		if (tid == 0) {
		tid = gettid();
		}
		policy = _policy(policy);
		pthread_once(&the_once, __initialize);

		int fd;
		switch (policy) {
		case SP_BACKGROUND:
		fd = bg_cpuset_fd;
		break;
		case SP_FOREGROUND:
		case SP_AUDIO_APP:
		case SP_AUDIO_SYS:
		fd = fg_cpuset_fd;
		break;
		default:
		fd = -1;
		break;
		}

		if (add_tid_to_cgroup(tid, fd) != 0) {
		if (errno != ESRCH && errno != ENOENT)
		return -errno;
		}

		// we do both setting of cpuset and setting of cgroup
		// ensures that backgrounded apps are actually deprioritized
		// including on core 0
		return set_sched_policy(tid, policy);
		#endif
		}

		int set_sched_policy(int tid, SchedPolicy policy)
		{
		if (tid == 0) {
		@@ -286,7 +326,23 @@ int set_sched_policy(int tid, SchedPolicy policy)
		#endif

		if (__sys_supports_schedgroups) {
		if (add_tid_to_cgroup(tid, policy)) {
		int fd;
		switch (policy) {
		case SP_BACKGROUND:
		fd = bg_cgroup_fd;
		break;
		case SP_FOREGROUND:
		case SP_AUDIO_APP:
		case SP_AUDIO_SYS:
		fd = fg_cgroup_fd;
		break;
		default:
		fd = -1;
		break;
		}


		if (add_tid_to_cgroup(tid, fd) != 0) {
		if (errno != ESRCH && errno != ENOENT)
		return -errno;
		}
		@@ -337,4 +393,3 @@ const char *get_sched_policy_name(SchedPolicy policy)
		else
		return "error";
		}

rootdir/init.rc

+22 −0

Original line number	Diff line number	Diff line
		@@ -125,6 +125,28 @@ on init
		write /dev/cpuctl/bg_non_interactive/cpu.rt_runtime_us 700000
		write /dev/cpuctl/bg_non_interactive/cpu.rt_period_us 1000000

		# sets up initial cpusets for ActivityManager
		mkdir /dev/cpuset
		mount cpuset none /dev/cpuset
		mkdir /dev/cpuset/foreground
		mkdir /dev/cpuset/background
		# this ensures that the cpusets are present and usable, but the device's
		# init.rc must actually set the correct cpus
		write /dev/cpuset/foreground/cpus 0
		write /dev/cpuset/background/cpus 0
		write /dev/cpuset/foreground/mems 0
		write /dev/cpuset/background/mems 0
		chown system system /dev/cpuset
		chown system system /dev/cpuset/foreground
		chown system system /dev/cpuset/background
		chown system system /dev/cpuset/tasks
		chown system system /dev/cpuset/foreground/tasks
		chown system system /dev/cpuset/background/tasks
		chmod 0644 /dev/cpuset/foreground/tasks
		chmod 0644 /dev/cpuset/background/tasks
		chmod 0644 /dev/cpuset/tasks


		# qtaguid will limit access to specific data based on group memberships.
		# net_bw_acct grants impersonation of socket owners.
		# net_bw_stats grants access to other apps' detailed tagged-socket stats.