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-rw-r--r--kernel/tsacct.c54
1 files changed, 30 insertions, 24 deletions
diff --git a/kernel/tsacct.c b/kernel/tsacct.c
index 975cb49e32bf..f8e26ab963ed 100644
--- a/kernel/tsacct.c
+++ b/kernel/tsacct.c
@@ -93,9 +93,11 @@ void xacct_add_tsk(struct taskstats *stats, struct task_struct *p)
{
struct mm_struct *mm;
- /* convert pages-usec to Mbyte-usec */
- stats->coremem = p->acct_rss_mem1 * PAGE_SIZE / MB;
- stats->virtmem = p->acct_vm_mem1 * PAGE_SIZE / MB;
+ /* convert pages-nsec/1024 to Mbyte-usec, see __acct_update_integrals */
+ stats->coremem = p->acct_rss_mem1 * PAGE_SIZE;
+ do_div(stats->coremem, 1000 * KB);
+ stats->virtmem = p->acct_vm_mem1 * PAGE_SIZE;
+ do_div(stats->virtmem, 1000 * KB);
mm = get_task_mm(p);
if (mm) {
/* adjust to KB unit */
@@ -123,27 +125,28 @@ void xacct_add_tsk(struct taskstats *stats, struct task_struct *p)
static void __acct_update_integrals(struct task_struct *tsk,
cputime_t utime, cputime_t stime)
{
- if (likely(tsk->mm)) {
- cputime_t time, dtime;
- struct timeval value;
- unsigned long flags;
- u64 delta;
-
- local_irq_save(flags);
- time = stime + utime;
- dtime = time - tsk->acct_timexpd;
- jiffies_to_timeval(cputime_to_jiffies(dtime), &value);
- delta = value.tv_sec;
- delta = delta * USEC_PER_SEC + value.tv_usec;
-
- if (delta == 0)
- goto out;
- tsk->acct_timexpd = time;
- tsk->acct_rss_mem1 += delta * get_mm_rss(tsk->mm);
- tsk->acct_vm_mem1 += delta * tsk->mm->total_vm;
- out:
- local_irq_restore(flags);
- }
+ cputime_t time, dtime;
+ u64 delta;
+
+ if (!likely(tsk->mm))
+ return;
+
+ time = stime + utime;
+ dtime = time - tsk->acct_timexpd;
+ /* Avoid division: cputime_t is often in nanoseconds already. */
+ delta = cputime_to_nsecs(dtime);
+
+ if (delta < TICK_NSEC)
+ return;
+
+ tsk->acct_timexpd = time;
+ /*
+ * Divide by 1024 to avoid overflow, and to avoid division.
+ * The final unit reported to userspace is Mbyte-usecs,
+ * the rest of the math is done in xacct_add_tsk.
+ */
+ tsk->acct_rss_mem1 += delta * get_mm_rss(tsk->mm) >> 10;
+ tsk->acct_vm_mem1 += delta * tsk->mm->total_vm >> 10;
}
/**
@@ -153,9 +156,12 @@ static void __acct_update_integrals(struct task_struct *tsk,
void acct_update_integrals(struct task_struct *tsk)
{
cputime_t utime, stime;
+ unsigned long flags;
+ local_irq_save(flags);
task_cputime(tsk, &utime, &stime);
__acct_update_integrals(tsk, utime, stime);
+ local_irq_restore(flags);
}
/**