From a776ac8d7331991be8298247d3547761bf54779b Mon Sep 17 00:00:00 2001 From: Andrew Morton Date: Sun, 31 Aug 2003 04:32:56 -0700 Subject: [PATCH] [PATCH] add context switch counters From: Peter Chubb Currently, the context switch counters reported by getrusage() are always zero. The appended patch adds fields to struct task_struct to count context switches, and adds code to do the counting. The patch adds 4 longs to struct task struct, and a single addition to the fast path in schedule(). --- include/linux/sched.h | 1 + kernel/exit.c | 2 ++ kernel/fork.c | 1 + kernel/sched.c | 4 +++- kernel/sys.c | 6 ++++++ 5 files changed, 13 insertions(+), 1 deletion(-) diff --git a/include/linux/sched.h b/include/linux/sched.h index 054168543a45e..3c6e3129144d4 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -391,6 +391,7 @@ struct task_struct { struct timer_list real_timer; struct list_head posix_timers; /* POSIX.1b Interval Timers */ unsigned long utime, stime, cutime, cstime; + unsigned long nvcsw, nivcsw, cnvcsw, cnivcsw; /* context switch counts */ u64 start_time; /* mm fault and swap info: this can arguably be seen as either mm-specific or thread-specific */ unsigned long min_flt, maj_flt, nswap, cmin_flt, cmaj_flt, cnswap; diff --git a/kernel/exit.c b/kernel/exit.c index a7328cc9992bf..b6174f82adf97 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -80,6 +80,8 @@ void release_task(struct task_struct * p) p->parent->cmin_flt += p->min_flt + p->cmin_flt; p->parent->cmaj_flt += p->maj_flt + p->cmaj_flt; p->parent->cnswap += p->nswap + p->cnswap; + p->parent->cnvcsw += p->nvcsw + p->cnvcsw; + p->parent->cnivcsw += p->nivcsw + p->cnivcsw; sched_exit(p); write_unlock_irq(&tasklist_lock); spin_unlock(&p->proc_lock); diff --git a/kernel/fork.c b/kernel/fork.c index 690b8d77a04bb..37d79b4e16e66 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -461,6 +461,7 @@ static int copy_mm(unsigned long clone_flags, struct task_struct * tsk) tsk->min_flt = tsk->maj_flt = 0; tsk->cmin_flt = tsk->cmaj_flt = 0; tsk->nswap = tsk->cnswap = 0; + tsk->nvcsw = tsk->nivcsw = tsk->cnvcsw = tsk->cnivcsw = 0; tsk->mm = NULL; tsk->active_mm = NULL; diff --git a/kernel/sched.c b/kernel/sched.c index 7a0dc4b1c4345..51241d70f924f 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -1325,8 +1325,10 @@ need_resched: } default: deactivate_task(prev, rq); + prev->nvcsw++; + break; case TASK_RUNNING: - ; + prev->nivcsw++; } pick_next_task: if (unlikely(!rq->nr_running)) { diff --git a/kernel/sys.c b/kernel/sys.c index 27c19703a1ea7..02b5a12dfd591 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -1309,6 +1309,8 @@ int getrusage(struct task_struct *p, int who, struct rusage __user *ru) case RUSAGE_SELF: jiffies_to_timeval(p->utime, &r.ru_utime); jiffies_to_timeval(p->stime, &r.ru_stime); + r.ru_nvcsw = p->nvcsw; + r.ru_nivcsw = p->nivcsw; r.ru_minflt = p->min_flt; r.ru_majflt = p->maj_flt; r.ru_nswap = p->nswap; @@ -1316,6 +1318,8 @@ int getrusage(struct task_struct *p, int who, struct rusage __user *ru) case RUSAGE_CHILDREN: jiffies_to_timeval(p->cutime, &r.ru_utime); jiffies_to_timeval(p->cstime, &r.ru_stime); + r.ru_nvcsw = p->cnvcsw; + r.ru_nivcsw = p->cnivcsw; r.ru_minflt = p->cmin_flt; r.ru_majflt = p->cmaj_flt; r.ru_nswap = p->cnswap; @@ -1323,6 +1327,8 @@ int getrusage(struct task_struct *p, int who, struct rusage __user *ru) default: jiffies_to_timeval(p->utime + p->cutime, &r.ru_utime); jiffies_to_timeval(p->stime + p->cstime, &r.ru_stime); + r.ru_nvcsw = p->nvcsw + p->cnvcsw; + r.ru_nivcsw = p->nivcsw + p->cnivcsw; r.ru_minflt = p->min_flt + p->cmin_flt; r.ru_majflt = p->maj_flt + p->cmaj_flt; r.ru_nswap = p->nswap + p->cnswap; -- 2.53.0