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Merge changes Ic85892b4,I627e47c6

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* changes:
  Make sure Zygote is running at process priority 0 after VM has started.
  Revert "Add boost to increase the load on newly-forked zygote processes."
This commit is contained in:
Treehugger Robot
2016-12-16 22:20:24 +00:00
committed by Gerrit Code Review
parent f8882ae834 1e52ce48a6
commit d995c94426
2 changed files with 21 additions and 36 deletions
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4
core/jni/Android.mk
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@@ -20,10 +20,6 @@ ifneq ($(ENABLE_CPUSETS),)
LOCAL_CFLAGS += -DENABLE_CPUSETS
endif
ifneq ($(ENABLE_SCHED_BOOST),)
LOCAL_CFLAGS += -DENABLE_SCHED_BOOST
endif
LOCAL_CFLAGS += -DGL_GLEXT_PROTOTYPES -DEGL_EGLEXT_PROTOTYPES
LOCAL_CFLAGS += -DU_USING_ICU_NAMESPACE=0

53
core/jni/com_android_internal_os_Zygote.cpp
View File

@@ -37,6 +37,7 @@
#include <sys/prctl.h>
#include <sys/resource.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/utsname.h>
#include <sys/wait.h>
@@ -153,6 +154,24 @@ static void SetSigChldHandler() {
}
}
// Resets nice priority for zygote process. Zygote priority can be set
// to high value during boot phase to speed it up. We want to ensure
// zygote is running at normal priority before childs are forked from it.
//
// This ends up being called repeatedly before each fork(), but there's
// no real harm in that.
static void ResetNicePriority(JNIEnv* env) {
errno = 0;
int prio = getpriority(PRIO_PROCESS, 0);
if (prio == -1 && errno != 0) {
ALOGW("getpriority failed: %s\n", strerror(errno));
}
if (prio != 0 && setpriority(PRIO_PROCESS, 0, 0) != 0) {
ALOGE("setpriority(%d, 0, 0) failed: %s", PRIO_PROCESS, strerror(errno));
RuntimeAbort(env, __LINE__, "setpriority failed");
}
}
// Sets the SIGCHLD handler back to default behavior in zygote children.
static void UnsetSigChldHandler() {
struct sigaction sa;
@@ -418,27 +437,6 @@ void SetThreadName(const char* thread_name) {
}
}
#ifdef ENABLE_SCHED_BOOST
static void SetForkLoad(bool boost) {
// set scheduler knob to boost forked processes
pid_t currentPid = getpid();
// fits at most "/proc/XXXXXXX/sched_init_task_load\0"
char schedPath[35];
snprintf(schedPath, sizeof(schedPath), "/proc/%u/sched_init_task_load", currentPid);
int schedBoostFile = open(schedPath, O_WRONLY);
if (schedBoostFile < 0) {
ALOGW("Unable to set zygote scheduler boost");
return;
}
if (boost) {
write(schedBoostFile, "100\0", 4);
} else {
write(schedBoostFile, "0\0", 2);
}
close(schedBoostFile);
}
#endif
// The list of open zygote file descriptors.
static FileDescriptorTable* gOpenFdTable = NULL;
@@ -452,10 +450,6 @@ static pid_t ForkAndSpecializeCommon(JNIEnv* env, uid_t uid, gid_t gid, jintArra
jstring instructionSet, jstring dataDir) {
SetSigChldHandler();
#ifdef ENABLE_SCHED_BOOST
SetForkLoad(true);
#endif
// Close any logging related FDs before we start evaluating the list of
// file descriptors.
__android_log_close();
@@ -472,6 +466,8 @@ static pid_t ForkAndSpecializeCommon(JNIEnv* env, uid_t uid, gid_t gid, jintArra
RuntimeAbort(env, __LINE__, "Unable to restat file descriptor table.");
}
ResetNicePriority(env);
pid_t pid = fork();
if (pid == 0) {
@@ -614,12 +610,6 @@ static pid_t ForkAndSpecializeCommon(JNIEnv* env, uid_t uid, gid_t gid, jintArra
}
} else if (pid > 0) {
// the parent process
#ifdef ENABLE_SCHED_BOOST
// unset scheduler knob
SetForkLoad(false);
#endif
}
return pid;
}
@@ -750,4 +740,3 @@ int register_com_android_internal_os_Zygote(JNIEnv* env) {
return RegisterMethodsOrDie(env, "com/android/internal/os/Zygote", gMethods, NELEM(gMethods));
}
} // namespace android