[PATCH][RFC] Re: accounting regression since rc1

Christian Borntraeger
2007-08-16T08:19:05Z

Ingo,

this patch fixes the accounting regression for CONFIG_VIRT_CPU_ACCOUNTING. It
reverts parts of commit b27f03d4bdc145a09fb7b0c0e004b29f1ee555fa by converting
fs/proc/array.c back to cputime_t. The new functions task_utime and
task_stime now return cputime_t instead of clock_t. If
CONFIG_VIRT_CPU_ACCOUTING is set, task->utime and task->stime are returned
directly instead of using sum_exec_runtime.

Patch is tested on s390x with and without VIRT_CPU_ACCOUTING as well as on
i386. Not tested on ppc64 - Paul?

Feedback is welcome.

Signed-Off-By: Christian Borntraeger <borntraeger@de.ibm.com>

---
fs/proc/array.c | 41 ++++++++++++++++++++++++++---------------
1 file changed, 26 insertions(+), 15 deletions(-)

Index: linux-2.6/fs/proc/array.c
===================================================================
--- linux-2.6.orig/fs/proc/array.c
+++ linux-2.6/fs/proc/array.c
@@ -320,7 +320,18 @@ int proc_pid_status(struct task_struct *
return buffer - orig;
}

-static clock_t task_utime(struct task_struct *p)
+#if defined(CONFIG_VIRT_CPU_ACCOUNTING)
+static cputime_t task_utime(struct task_struct *p)
+{
+ return p->utime;
+}
+
+static cputime_t task_stime(struct task_struct *p)
+{
+ return p->stime;
+}
+#else
+static cputime_t task_utime(struct task_struct *p)
{
clock_t utime = cputime_to_clock_t(p->utime),
total = utime + cputime_to_clock_t(p->stime);
@@ -337,10 +348,10 @@ static clock_t task_utime(struct task_st
}
utime = (clock_t)temp;

- return utime;
+ return clock_t_to_cputime(utime);
}

-static clock_t task_stime(struct task_struct *p)
+static cputime_t task_stime(struct task_struct *p)
{
clock_t stime;

@@ -349,10 +360,12 @@ static clock_t task_stime(struct task_st
* the total, to make sure the total observed by userspace
* grows monotonically - apps rely on that):
*/
- stime = nsec_to_clock_t(p->se.sum_exec_runtime) - task_utime(p);
+ stime = nsec_to_clock_t(p->se.sum_exec_runtime) -
+ cputime_to_clock_t(task_utime(p));

- return stime;
+ return clock_t_to_cputime(stime);
}
+#endif

static int do_task_stat(struct task_struct *task, char *buffer, int whole)
{
@@ -368,8 +381,7 @@ static int do_task_stat(struct task_stru
unsigned long long start_time;
unsigned long cmin_flt = 0, cmaj_flt = 0;
unsigned long min_flt = 0, maj_flt = 0;
- cputime_t cutime, cstime;
- clock_t utime, stime;
+ cputime_t cutime, cstime, utime, stime;
unsigned long rsslim = 0;
char tcomm[sizeof(task->comm)];
unsigned long flags;
@@ -387,8 +399,7 @@ static int do_task_stat(struct task_stru

sigemptyset(&sigign);
sigemptyset(&sigcatch);
- cutime = cstime = cputime_zero;
- utime = stime = 0;
+ cutime = cstime = utime = stime = cputime_zero;

rcu_read_lock();
if (lock_task_sighand(task, &flags)) {
@@ -414,15 +425,15 @@ static int do_task_stat(struct task_stru
do {
min_flt += t->min_flt;
maj_flt += t->maj_flt;
- utime += task_utime(t);
- stime += task_stime(t);
+ utime = cputime_add(utime, task_utime(t));
+ stime = cputime_add(stime, task_stime(t));
t = next_thread(t);
} while (t != task);

min_flt += sig->min_flt;
maj_flt += sig->maj_flt;
- utime += cputime_to_clock_t(sig->utime);
- stime += cputime_to_clock_t(sig->stime);
+ utime = cputime_add(utime, sig->utime);
+ stime = cputime_add(stime, sig->stime);
}

sid = signal_session(sig);
@@ -471,8 +482,8 @@ static int do_task_stat(struct task_stru
cmin_flt,
maj_flt,
cmaj_flt,
- utime,
- stime,
+ cputime_to_clock_t(utime),
+ cputime_to_clock_t(stime),
cputime_to_clock_t(cutime),
cputime_to_clock_t(cstime),
priority,