[PATCH] sched: avoid div in rebalance_tick

[pandora-kernel.git] / kernel / tsacct.c

diff --git a/kernel/tsacct.c b/kernel/tsacct.c
index 4104834..baacc36 100644 (file)
--- 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)
@@ -35,7 +36,7 @@ void bacct_add_tsk(struct taskstats *stats, struct task_struct *tsk)
 
        /* calculate task elapsed time in timespec */
        do_posix_clock_monotonic_gettime(&uptime);
-       ts = timespec_sub(uptime, current->group_leader->start_time);
+       ts = timespec_sub(uptime, tsk->start_time);
        /* rebase elapsed time to usec */
        ac_etime = timespec_to_ns(&ts);
        do_div(ac_etime, NSEC_PER_USEC);
@@ -57,35 +58,83 @@ void bacct_add_tsk(struct taskstats *stats, struct task_struct *tsk)
        stats->ac_uid    = tsk->uid;
        stats->ac_gid    = tsk->gid;
        stats->ac_pid    = tsk->pid;
-       stats->ac_ppid   = (tsk->parent) ? tsk->parent->pid : 0;
+       rcu_read_lock();
+       stats->ac_ppid   = pid_alive(tsk) ?
+                               rcu_dereference(tsk->real_parent)->tgid : 0;
+       rcu_read_unlock();
        stats->ac_utime  = cputime_to_msecs(tsk->utime) * USEC_PER_MSEC;
        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;
-       if (p->mm) {
-               stats->hiwater_rss   = p->mm->hiwater_rss;
-               stats->hiwater_vm    = p->mm->hiwater_vm;
+       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;
+       mm = get_task_mm(p);
+       if (mm) {
+               /* adjust to KB unit */
+               stats->hiwater_rss   = mm->hiwater_rss * PAGE_SIZE / KB;
+               stats->hiwater_vm    = mm->hiwater_vm * PAGE_SIZE / KB;
+               mmput(mm);
        }
        stats->read_char        = p->rchar;
        stats->write_char       = p->wchar;
        stats->read_syscalls    = p->syscr;
        stats->write_syscalls   = p->syscw;
+#ifdef CONFIG_TASK_IO_ACCOUNTING
+       stats->read_bytes       = p->ioac.read_bytes;
+       stats->write_bytes      = p->ioac.write_bytes;
+       stats->cancelled_write_bytes = p->ioac.cancelled_write_bytes;
+#else
+       stats->read_bytes       = 0;
+       stats->write_bytes      = 0;
+       stats->cancelled_write_bytes = 0;
+#endif
+}
+#undef KB
+#undef MB
+
+/**
+ * acct_update_integrals - update mm integral fields in task_struct
+ * @tsk: task_struct for accounting
+ */
+void acct_update_integrals(struct task_struct *tsk)
+{
+       if (likely(tsk->mm)) {
+               long delta = cputime_to_jiffies(
+                       cputime_sub(tsk->stime, tsk->acct_stimexpd));
+
+               if (delta == 0)
+                       return;
+               tsk->acct_stimexpd = tsk->stime;
+               tsk->acct_rss_mem1 += delta * get_mm_rss(tsk->mm);
+               tsk->acct_vm_mem1 += delta * tsk->mm->total_vm;
+       }
+}
+
+/**
+ * acct_clear_integrals - clear the mm integral fields in task_struct
+ * @tsk: task_struct whose accounting fields are cleared
+ */
+void acct_clear_integrals(struct task_struct *tsk)
+{
+       tsk->acct_stimexpd = 0;
+       tsk->acct_rss_mem1 = 0;
+       tsk->acct_vm_mem1 = 0;
 }
 #endif