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authorFrederic Weisbecker <fweisbec@gmail.com>2012-11-22 00:58:35 +0100
committerFrederic Weisbecker <fweisbec@gmail.com>2012-11-28 17:08:10 +0100
commitd37f761dbd276790f70dcf73a287fde2c3464482 (patch)
tree302d4bda699ab2e159b3a180f253019a38bf8132
parente80d0a1ae8bb8fee0edd37427836f108b30f596b (diff)
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cputime: Consolidate cputime adjustment code
task_cputime_adjusted() and thread_group_cputime_adjusted() essentially share the same code. They just don't use the same source: * The first function uses the cputime in the task struct and the previous adjusted snapshot that ensures monotonicity. * The second adds the cputime of all tasks in the group and the previous adjusted snapshot of the whole group from the signal structure. Just consolidate the common code that does the adjustment. These functions just need to fetch the values from the appropriate source. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
-rw-r--r--include/linux/sched.h23
-rw-r--r--kernel/fork.c2
-rw-r--r--kernel/sched/cputime.c46
3 files changed, 43 insertions, 28 deletions
diff --git a/include/linux/sched.h b/include/linux/sched.h
index e75cab5820a..5dafac36681 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -434,13 +434,28 @@ struct cpu_itimer {
};
/**
+ * struct cputime - snaphsot of system and user cputime
+ * @utime: time spent in user mode
+ * @stime: time spent in system mode
+ *
+ * Gathers a generic snapshot of user and system time.
+ */
+struct cputime {
+ cputime_t utime;
+ cputime_t stime;
+};
+
+/**
* struct task_cputime - collected CPU time counts
* @utime: time spent in user mode, in &cputime_t units
* @stime: time spent in kernel mode, in &cputime_t units
* @sum_exec_runtime: total time spent on the CPU, in nanoseconds
*
- * This structure groups together three kinds of CPU time that are
- * tracked for threads and thread groups. Most things considering
+ * This is an extension of struct cputime that includes the total runtime
+ * spent by the task from the scheduler point of view.
+ *
+ * As a result, this structure groups together three kinds of CPU time
+ * that are tracked for threads and thread groups. Most things considering
* CPU time want to group these counts together and treat all three
* of them in parallel.
*/
@@ -581,7 +596,7 @@ struct signal_struct {
cputime_t gtime;
cputime_t cgtime;
#ifndef CONFIG_VIRT_CPU_ACCOUNTING
- cputime_t prev_utime, prev_stime;
+ struct cputime prev_cputime;
#endif
unsigned long nvcsw, nivcsw, cnvcsw, cnivcsw;
unsigned long min_flt, maj_flt, cmin_flt, cmaj_flt;
@@ -1340,7 +1355,7 @@ struct task_struct {
cputime_t utime, stime, utimescaled, stimescaled;
cputime_t gtime;
#ifndef CONFIG_VIRT_CPU_ACCOUNTING
- cputime_t prev_utime, prev_stime;
+ struct cputime prev_cputime;
#endif
unsigned long nvcsw, nivcsw; /* context switch counts */
struct timespec start_time; /* monotonic time */
diff --git a/kernel/fork.c b/kernel/fork.c
index 8b20ab7d3aa..0e7cdb90476 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1222,7 +1222,7 @@ static struct task_struct *copy_process(unsigned long clone_flags,
p->utime = p->stime = p->gtime = 0;
p->utimescaled = p->stimescaled = 0;
#ifndef CONFIG_VIRT_CPU_ACCOUNTING
- p->prev_utime = p->prev_stime = 0;
+ p->prev_cputime.utime = p->prev_cputime.stime = 0;
#endif
#if defined(SPLIT_RSS_COUNTING)
memset(&p->rss_stat, 0, sizeof(p->rss_stat));
diff --git a/kernel/sched/cputime.c b/kernel/sched/cputime.c
index 7dc155371b9..220fdc4db77 100644
--- a/kernel/sched/cputime.c
+++ b/kernel/sched/cputime.c
@@ -516,14 +516,18 @@ static cputime_t scale_utime(cputime_t utime, cputime_t rtime, cputime_t total)
return (__force cputime_t) temp;
}
-void task_cputime_adjusted(struct task_struct *p, cputime_t *ut, cputime_t *st)
+static void cputime_adjust(struct task_cputime *curr,
+ struct cputime *prev,
+ cputime_t *ut, cputime_t *st)
{
- cputime_t rtime, utime = p->utime, total = utime + p->stime;
+ cputime_t rtime, utime, total;
+ utime = curr->utime;
+ total = utime + curr->stime;
/*
* Use CFS's precise accounting:
*/
- rtime = nsecs_to_cputime(p->se.sum_exec_runtime);
+ rtime = nsecs_to_cputime(curr->sum_exec_runtime);
if (total)
utime = scale_utime(utime, rtime, total);
@@ -533,11 +537,22 @@ void task_cputime_adjusted(struct task_struct *p, cputime_t *ut, cputime_t *st)
/*
* Compare with previous values, to keep monotonicity:
*/
- p->prev_utime = max(p->prev_utime, utime);
- p->prev_stime = max(p->prev_stime, rtime - p->prev_utime);
+ prev->utime = max(prev->utime, utime);
+ prev->stime = max(prev->stime, rtime - prev->utime);
+
+ *ut = prev->utime;
+ *st = prev->stime;
+}
- *ut = p->prev_utime;
- *st = p->prev_stime;
+void task_cputime_adjusted(struct task_struct *p, cputime_t *ut, cputime_t *st)
+{
+ struct task_cputime cputime = {
+ .utime = p->utime,
+ .stime = p->stime,
+ .sum_exec_runtime = p->se.sum_exec_runtime,
+ };
+
+ cputime_adjust(&cputime, &p->prev_cputime, ut, st);
}
/*
@@ -545,24 +560,9 @@ void task_cputime_adjusted(struct task_struct *p, cputime_t *ut, cputime_t *st)
*/
void thread_group_cputime_adjusted(struct task_struct *p, cputime_t *ut, cputime_t *st)
{
- struct signal_struct *sig = p->signal;
struct task_cputime cputime;
- cputime_t rtime, utime, total;
thread_group_cputime(p, &cputime);
-
- total = cputime.utime + cputime.stime;
- rtime = nsecs_to_cputime(cputime.sum_exec_runtime);
-
- if (total)
- utime = scale_utime(cputime.utime, rtime, total);
- else
- utime = rtime;
-
- sig->prev_utime = max(sig->prev_utime, utime);
- sig->prev_stime = max(sig->prev_stime, rtime - sig->prev_utime);
-
- *ut = sig->prev_utime;
- *st = sig->prev_stime;
+ cputime_adjust(&cputime, &p->signal->prev_cputime, ut, st);
}
#endif