Merge "Removed cpusets/schedboost build time dependency." am: d3f8d28db2

am: e60efc1b0b

Change-Id: Ie2d15917ea237c026bee7a526a75bf2544313580

libcutils/Android.bp

@@ -60,7 +60,7 @@ cc_library {
         "native_handle.c",
         "open_memstream.c",
         "record_stream.c",
-        "sched_policy.c",
+        "sched_policy.cpp",
         "sockets.cpp",
         "strdup16to8.c",
         "strdup8to16.c",
@@ -141,14 +141,6 @@ cc_library {
     header_libs: ["libcutils_headers"],
     export_header_lib_headers: ["libcutils_headers"],
 
-    product_variables: {
-        cpusets: {
-            cflags: ["-DUSE_CPUSETS"],
-        },
-        schedboost: {
-            cflags: ["-DUSE_SCHEDBOOST"],
-        },
-    },
     cflags: [
         "-Werror",
         "-Wall",

libcutils/include/cutils/sched_policy.h

@@ -17,10 +17,27 @@
 #ifndef __CUTILS_SCHED_POLICY_H
 #define __CUTILS_SCHED_POLICY_H
 
+#include <stdbool.h>
+
 #ifdef __cplusplus
 extern "C" {
 #endif
 
+/*
+ * Check if Linux kernel enables CPUSETS feature.
+ *
+ * Return value: 1 if Linux kernel CONFIG_CPUSETS=y; 0 otherwise.
+ */
+extern bool cpusets_enabled();
+
+/*
+ * Check if Linux kernel enables SCHEDTUNE feature (only available in Android
+ * common kernel or Linaro LSK, not in mainline Linux as of v4.9)
+ *
+ * Return value: 1 if Linux kernel CONFIG_SCHEDTUNE=y; 0 otherwise.
+ */
+extern bool schedboost_enabled();
+
 /* Keep in sync with THREAD_GROUP_* in frameworks/base/core/java/android/os/Process.java */
 typedef enum {
     SP_DEFAULT    = -1,

libcutils/sched_policy.cpp

@@ -58,13 +58,11 @@ static int __sys_supports_timerslack = -1;
 static int bg_cgroup_fd = -1;
 static int fg_cgroup_fd = -1;
 
-#ifdef USE_CPUSETS
 // File descriptors open to /dev/cpuset/../tasks, setup by initialize, or -1 on error
 static int system_bg_cpuset_fd = -1;
 static int bg_cpuset_fd = -1;
 static int fg_cpuset_fd = -1;
 static int ta_cpuset_fd = -1; // special cpuset for top app
-#endif
 
 // File descriptors open to /dev/stune/../tasks, setup by initialize, or -1 on error
 static int bg_schedboost_fd = -1;
@@ -106,8 +104,53 @@ static int add_tid_to_cgroup(int tid, int fd)
     return 0;
 }
 
-static void __initialize(void) {
+/*
-    char* filename;
+    If CONFIG_CPUSETS for Linux kernel is set, "tasks" can be found under
+    /dev/cpuset mounted in init.rc; otherwise, that file does not exist
+    even though the directory, /dev/cpuset, is still created (by init.rc).
+
+    A couple of other candidates (under cpuset mount directory):
+        notify_on_release
+        release_agent
+
+    Yet another way to decide if cpuset is enabled is to parse
+    /proc/self/status and search for lines begin with "Mems_allowed".
+
+    If CONFIG_PROC_PID_CPUSET is set, the existence "/proc/self/cpuset" can
+    be used to decide if CONFIG_CPUSETS is set, so we don't have a dependency
+    on where init.rc mounts cpuset. That's why we'd better require this
+    configuration be set if CONFIG_CPUSETS is set.
+
+    With runtime check using the following function, build time
+    variables like ENABLE_CPUSETS (used in Android.mk) or cpusets (used
+    in Android.bp) are not needed.
+ */
+
+bool cpusets_enabled() {
+    static bool enabled = (access("/dev/cpuset/tasks", F_OK) == 0);
+
+    return enabled;
+}
+
+/*
+    Similar to CONFIG_CPUSETS above, but with a different configuration
+    CONFIG_SCHEDTUNE that's in Android common Linux kernel and Linaro
+    Stable Kernel (LSK), but not in mainline Linux as of v4.9.
+
+    With runtime check using the following function, build time
+    variables like ENABLE_SCHEDBOOST (used in Android.mk) or schedboost
+    (used in Android.bp) are not needed.
+
+ */
+
+bool schedboost_enabled() {
+    static bool enabled = (access("/dev/stune/tasks", F_OK) == 0);
+
+    return enabled;
+}
+
+static void __initialize() {
+    const char* filename;
     if (!access("/dev/cpuctl/tasks", W_OK)) {
         __sys_supports_schedgroups = 1;
 
@@ -126,28 +169,28 @@ static void __initialize(void) {
         __sys_supports_schedgroups = 0;
     }
 
-#ifdef USE_CPUSETS
+    if (cpusets_enabled()) {
-    if (!access("/dev/cpuset/tasks", W_OK)) {
+        if (!access("/dev/cpuset/tasks", W_OK)) {
 
-        filename = "/dev/cpuset/foreground/tasks";
+            filename = "/dev/cpuset/foreground/tasks";
-        fg_cpuset_fd = open(filename, O_WRONLY | O_CLOEXEC);
+            fg_cpuset_fd = open(filename, O_WRONLY | O_CLOEXEC);
-        filename = "/dev/cpuset/background/tasks";
+            filename = "/dev/cpuset/background/tasks";
-        bg_cpuset_fd = open(filename, O_WRONLY | O_CLOEXEC);
+            bg_cpuset_fd = open(filename, O_WRONLY | O_CLOEXEC);
-        filename = "/dev/cpuset/system-background/tasks";
+            filename = "/dev/cpuset/system-background/tasks";
-        system_bg_cpuset_fd = open(filename, O_WRONLY | O_CLOEXEC);
+            system_bg_cpuset_fd = open(filename, O_WRONLY | O_CLOEXEC);
-        filename = "/dev/cpuset/top-app/tasks";
+            filename = "/dev/cpuset/top-app/tasks";
-        ta_cpuset_fd = open(filename, O_WRONLY | O_CLOEXEC);
+            ta_cpuset_fd = open(filename, O_WRONLY | O_CLOEXEC);
 
-#ifdef USE_SCHEDBOOST
+            if (schedboost_enabled()) {
-        filename = "/dev/stune/top-app/tasks";
+                filename = "/dev/stune/top-app/tasks";
-        ta_schedboost_fd = open(filename, O_WRONLY | O_CLOEXEC);
+                ta_schedboost_fd = open(filename, O_WRONLY | O_CLOEXEC);
-        filename = "/dev/stune/foreground/tasks";
+                filename = "/dev/stune/foreground/tasks";
-        fg_schedboost_fd = open(filename, O_WRONLY | O_CLOEXEC);
+                fg_schedboost_fd = open(filename, O_WRONLY | O_CLOEXEC);
-        filename = "/dev/stune/background/tasks";
+                filename = "/dev/stune/background/tasks";
-        bg_schedboost_fd = open(filename, O_WRONLY | O_CLOEXEC);
+                bg_schedboost_fd = open(filename, O_WRONLY | O_CLOEXEC);
-#endif
+            }
+        }
     }
-#endif
 
     char buf[64];
     snprintf(buf, sizeof(buf), "/proc/%d/timerslack_ns", getpid());
@@ -235,33 +278,34 @@ int get_sched_policy(int tid, SchedPolicy *policy)
 
     if (__sys_supports_schedgroups) {
         char grpBuf[32];
-#ifdef USE_CPUSETS
+
-        if (getCGroupSubsys(tid, "cpuset", grpBuf, sizeof(grpBuf)) < 0)
+        if (cpusets_enabled()) {
-            return -1;
+            if (getCGroupSubsys(tid, "cpuset", grpBuf, sizeof(grpBuf)) < 0)
-        if (grpBuf[0] == '\0') {
+                return -1;
-            *policy = SP_FOREGROUND;
+            if (grpBuf[0] == '\0') {
-        } else if (!strcmp(grpBuf, "foreground")) {
+                *policy = SP_FOREGROUND;
-            *policy = SP_FOREGROUND;
+            } else if (!strcmp(grpBuf, "foreground")) {
-        } else if (!strcmp(grpBuf, "background")) {
+                *policy = SP_FOREGROUND;
-            *policy = SP_BACKGROUND;
+            } else if (!strcmp(grpBuf, "background")) {
-        } else if (!strcmp(grpBuf, "top-app")) {
+                *policy = SP_BACKGROUND;
-            *policy = SP_TOP_APP;
+            } else if (!strcmp(grpBuf, "top-app")) {
+                *policy = SP_TOP_APP;
+            } else {
+                errno = ERANGE;
+                return -1;
+            }
         } else {
-            errno = ERANGE;
+            if (getCGroupSubsys(tid, "cpu", grpBuf, sizeof(grpBuf)) < 0)
-            return -1;
+                return -1;
+            if (grpBuf[0] == '\0') {
+                *policy = SP_FOREGROUND;
+            } else if (!strcmp(grpBuf, "bg_non_interactive")) {
+                *policy = SP_BACKGROUND;
+            } else {
+                errno = ERANGE;
+                return -1;
+            }
         }
-#else
-        if (getCGroupSubsys(tid, "cpu", grpBuf, sizeof(grpBuf)) < 0)
-            return -1;
-        if (grpBuf[0] == '\0') {
-            *policy = SP_FOREGROUND;
-        } else if (!strcmp(grpBuf, "bg_non_interactive")) {
-            *policy = SP_BACKGROUND;
-        } else {
-            errno = ERANGE;
-            return -1;
-        }
-#endif
     } else {
         int rc = sched_getscheduler(tid);
         if (rc < 0)
@@ -281,9 +325,10 @@ int get_sched_policy(int tid, SchedPolicy *policy)
 int set_cpuset_policy(int tid, SchedPolicy policy)
 {
     // in the absence of cpusets, use the old sched policy
-#ifndef USE_CPUSETS
+    if (!cpusets_enabled()) {
-    return set_sched_policy(tid, policy);
+        return set_sched_policy(tid, policy);
-#else
+    }
+
     if (tid == 0) {
         tid = gettid();
     }
@@ -320,15 +365,14 @@ int set_cpuset_policy(int tid, SchedPolicy policy)
             return -errno;
     }
 
-#ifdef USE_SCHEDBOOST
+    if (schedboost_enabled()) {
-    if (boost_fd > 0 && add_tid_to_cgroup(tid, boost_fd) != 0) {
+        if (boost_fd > 0 && add_tid_to_cgroup(tid, boost_fd) != 0) {
-        if (errno != ESRCH && errno != ENOENT)
+            if (errno != ESRCH && errno != ENOENT)
-            return -errno;
+                return -errno;
+        }
     }
-#endif
 
     return 0;
-#endif
 }
 
 static void set_timerslack_ns(int tid, unsigned long long slack) {
@@ -420,18 +464,17 @@ int set_sched_policy(int tid, SchedPolicy policy)
             break;
         }
 
-
         if (add_tid_to_cgroup(tid, fd) != 0) {
             if (errno != ESRCH && errno != ENOENT)
                 return -errno;
         }
 
-#ifdef USE_SCHEDBOOST
+        if (schedboost_enabled()) {
-        if (boost_fd > 0 && add_tid_to_cgroup(tid, boost_fd) != 0) {
+            if (boost_fd > 0 && add_tid_to_cgroup(tid, boost_fd) != 0) {
-            if (errno != ESRCH && errno != ENOENT)
+                if (errno != ESRCH && errno != ENOENT)
-                return -errno;
+                    return -errno;
+            }
         }
-#endif
     } else {
         struct sched_param param;