accounting: account for user time when updating memory integrals

Adapt acct_update_integrals() to include user time when calculating the time
difference.  The units of acct_rss_mem1 and acct_vm_mem1 are also changed from
pages-jiffies to pages-usecs to avoid calling jiffies_to_usecs() in
xacct_add_tsk() which might overflow.

Signed-off-by: Jonathan Lim <jlim@sgi.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 14 insertions, 7 deletions

diff --git a/kernel/tsacct.c b/kernel/tsacct.c
index 4ab1b584961b..1da6990af8e0 100644
--- a/kernel/tsacct.c
+++ b/kernel/tsacct.c
@@ -84,9 +84,9 @@ void xacct_add_tsk(struct taskstats *stats, struct task_struct *p)
 {
         struct mm_struct *mm;
 
-        /* convert pages-jiffies to Mbyte-usec */
-        stats->coremem = jiffies_to_usecs(p->acct_rss_mem1) * PAGE_SIZE / MB;
-        stats->virtmem = jiffies_to_usecs(p->acct_vm_mem1) * PAGE_SIZE / MB;
+        /* convert pages-usec to Mbyte-usec */
+        stats->coremem = p->acct_rss_mem1 * PAGE_SIZE / MB;
+        stats->virtmem = p->acct_vm_mem1 * PAGE_SIZE / MB;
         mm = get_task_mm(p);
         if (mm) {
                 /* adjust to KB unit */
@@ -118,12 +118,19 @@ void xacct_add_tsk(struct taskstats *stats, struct task_struct *p)
 void acct_update_integrals(struct task_struct *tsk)
 {
         if (likely(tsk->mm)) {
-                long delta = cputime_to_jiffies(
-                        cputime_sub(tsk->stime, tsk->acct_stimexpd));
+                cputime_t time, dtime;
+                struct timeval value;
+                u64 delta;
+
+                time = tsk->stime + tsk->utime;
+                dtime = cputime_sub(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)
                         return;
-                tsk->acct_stimexpd = tsk->stime;
+                tsk->acct_timexpd = time;
                 tsk->acct_rss_mem1 += delta * get_mm_rss(tsk->mm);
                 tsk->acct_vm_mem1 += delta * tsk->mm->total_vm;
         }
@@ -135,7 +142,7 @@ void acct_update_integrals(struct task_struct *tsk)
  */
 void acct_clear_integrals(struct task_struct *tsk)
 {
-        tsk->acct_stimexpd = 0;
+        tsk->acct_timexpd = 0;
         tsk->acct_rss_mem1 = 0;
         tsk->acct_vm_mem1 = 0;
 }