am 253e27ac: Optimize set_sched_policy(), which gets called in every binder call.

Merge commit '253e27acb6c9e3e0b03c59f25cdf9ecbd64bcdad' into froyo-plus-aosp

* commit '253e27acb6c9e3e0b03c59f25cdf9ecbd64bcdad':
  Optimize set_sched_policy(), which gets called in every binder call.
This commit is contained in:
Brad Fitzpatrick 2010-05-06 12:39:30 -07:00 committed by Android Git Automerger
commit ba9025ce95
1 changed files with 22 additions and 16 deletions

View File

@ -44,22 +44,27 @@
static int __sys_supports_schedgroups = -1;
static int add_tid_to_cgroup(int tid, const char *grp_name)
/* Add tid to the group defined by dev_path ("/dev/cpuctl/.../tasks") */
static int add_tid_to_cgroup(int tid, const char *dev_path)
{
int fd;
char path[255];
char text[64];
sprintf(path, "/dev/cpuctl/%s/tasks", grp_name);
if ((fd = open(path, O_WRONLY)) < 0) {
SLOGE("add_tid_to_cgroup failed to open '%s' (%s)\n", path,
if ((fd = open(dev_path, O_WRONLY)) < 0) {
SLOGE("add_tid_to_cgroup failed to open '%s' (%s)\n", dev_path,
strerror(errno));
return -1;
}
sprintf(text, "%d", tid);
if (write(fd, text, strlen(text)) < 0) {
// specialized itoa -- works for tid > 0
char text[22];
char *end = text + sizeof(text) - 1;
char *ptr = end;
*ptr = '\0';
while (tid > 0) {
*--ptr = '0' + (tid % 10);
tid = tid / 10;
}
if (write(fd, ptr, end - ptr) < 0) {
close(fd);
/*
* If the thread is in the process of exiting,
@ -67,8 +72,8 @@ static int add_tid_to_cgroup(int tid, const char *grp_name)
*/
if (errno == ESRCH)
return 0;
SLOGW("add_tid_to_cgroup failed to write '%s' (%s)\n", path,
strerror(errno));
SLOGW("add_tid_to_cgroup failed to write '%s' to '%s' (%s)\n",
ptr, dev_path, strerror(errno));
return -1;
}
@ -228,13 +233,14 @@ int set_sched_policy(int tid, SchedPolicy policy)
#endif
if (__sys_supports_schedgroups) {
const char *grp = "";
const char *dev_path;
if (policy == SP_BACKGROUND) {
grp = "bg_non_interactive";
dev_path = "/dev/cpuctl/bg_non_interactive/tasks";
} else {
dev_path = "/dev/cpuctl/tasks";
}
if (add_tid_to_cgroup(tid, grp)) {
if (add_tid_to_cgroup(tid, dev_path)) {
if (errno != ESRCH && errno != ENOENT)
return -errno;
}