[PATCH] csa accounting taskstats update

ChangeLog:
   Feedbacks from Andrew Morton:
   - define TS_COMM_LEN to 32
   - change acct_stimexpd field of task_struct to be of
     cputime_t, which is to be used to save the tsk->stime
     of last timer interrupt update.
   - a new Documentation/accounting/taskstats-struct.txt
     to describe fields of taskstats struct.

   Feedback from Balbir Singh:
   - keep the stime of a task to be zero when both stime
     and utime are zero as recoreded in task_struct.

   Misc:
   - convert accumulated RSS/VM from platform dependent
     pages-ticks to MBytes-usecs in the kernel

Cc: Shailabh Nagar <nagar@watson.ibm.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Jes Sorensen <jes@sgi.com>
Cc: Chris Sturtivant <csturtiv@sgi.com>
Cc: Tony Ernst <tee@sgi.com>
Cc: Guillaume Thouvenin <guillaume.thouvenin@bull.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 14 insertions, 11 deletions

diff --git a/kernel/tsacct.c b/kernel/tsacct.c
index 47c71daa416f..db443221ba5b 100644
--- a/kernel/tsacct.c
+++ b/kernel/tsacct.c
@@ -20,6 +20,7 @@
 #include <linux/sched.h>
 #include <linux/tsacct_kern.h>
 #include <linux/acct.h>
+#include <linux/jiffies.h>
 
 
 #define USEC_PER_TICK   (USEC_PER_SEC/HZ)
@@ -62,33 +63,35 @@ void bacct_add_tsk(struct taskstats *stats, struct task_struct *tsk)
         stats->ac_stime  = cputime_to_msecs(tsk->stime) * USEC_PER_MSEC;
         stats->ac_minflt = tsk->min_flt;
         stats->ac_majflt = tsk->maj_flt;
-        /* Each process gets a minimum of one usec cpu time */
-        if ((stats->ac_utime == 0) && (stats->ac_stime == 0)) {
-                stats->ac_stime = 1;
-        }
 
         strncpy(stats->ac_comm, tsk->comm, sizeof(stats->ac_comm));
 }
 
 
 #ifdef CONFIG_TASK_XACCT
+
+#define KB 1024
+#define MB (1024*KB)
 /*
  * fill in extended accounting fields
  */
 void xacct_add_tsk(struct taskstats *stats, struct task_struct *p)
 {
-        stats->acct_rss_mem1 = p->acct_rss_mem1;
-        stats->acct_vm_mem1  = p->acct_vm_mem1;
+        /* 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;
         if (p->mm) {
-                stats->hiwater_rss   = p->mm->hiwater_rss;
-                stats->hiwater_vm    = p->mm->hiwater_vm;
+                /* adjust to KB unit */
+                stats->hiwater_rss   = p->mm->hiwater_rss * PAGE_SIZE / KB;
+                stats->hiwater_vm    = p->mm->hiwater_vm * PAGE_SIZE / KB;
         }
         stats->read_char        = p->rchar;
         stats->write_char       = p->wchar;
         stats->read_syscalls    = p->syscr;
         stats->write_syscalls   = p->syscw;
 }
-
+#undef KB
+#undef MB
 
 /**
  * acct_update_integrals - update mm integral fields in task_struct
@@ -97,8 +100,8 @@ 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(tsk->stime) - tsk->acct_stimexpd;
+                long delta = cputime_to_jiffies(
+                        cputime_sub(tsk->stime, tsk->acct_stimexpd));
 
                 if (delta == 0)
                         return;