From: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
To: linux-kernel@vger.kernel.org
Cc: Fernando Luis Vazquez Cao <fernando_b1@lab.ntt.co.jp>,
Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>,
Frederic Weisbecker <fweisbec@gmail.com>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Andrew Morton <akpm@linux-foundation.org>,
Arjan van de Ven <arjan@linux.intel.com>,
Oleg Nesterov <oleg@redhat.com>,
Preeti U Murthy <preeti@linux.vnet.ibm.com>,
Denys Vlasenko <vda.linux@googlemail.com>
Subject: [PATCH 4/8] cputime, s390: introduce s390_get_idle_and_iowait
Date: Thu, 26 Jun 2014 18:12:13 +0900 [thread overview]
Message-ID: <53ABE3ED.4000901@jp.fujitsu.com> (raw)
In-Reply-To: <53ABE28F.6010402@jp.fujitsu.com>
s390_get_idle_time give us the duration from idle entry to now.
But it does not tell us how to divide it to idle and iowait.
Modify this function to return 2 values. To realize this, s390's
cputime accounting also requires timestamp at end of iowait.
Not-Tested-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
---
arch/s390/include/asm/cputime.h | 7 ++++-
arch/s390/kernel/vtime.c | 40 ++++++++++++++++++++++++++++++++------
fs/proc/stat.c | 20 +++++++++++-------
kernel/sched/core.c | 6 ++++-
4 files changed, 55 insertions(+), 18 deletions(-)
diff --git a/arch/s390/include/asm/cputime.h b/arch/s390/include/asm/cputime.h
index f65bd36..f4f882d 100644
--- a/arch/s390/include/asm/cputime.h
+++ b/arch/s390/include/asm/cputime.h
@@ -174,13 +174,16 @@ struct s390_idle_data {
unsigned long long clock_idle_exit;
unsigned long long timer_idle_enter;
unsigned long long timer_idle_exit;
+ unsigned long long clock_iowait_exit;
};
DECLARE_PER_CPU(struct s390_idle_data, s390_idle);
-cputime64_t s390_get_idle_time(int cpu);
+void s390_get_idle_and_iowait(int cpu, cputime64_t reti, cputime64_t retw);
+void s390_record_iowait_exit(int cpu);
-#define arch_idle_time(cpu) s390_get_idle_time(cpu)
+#define arch_idle_and_iowait(cpu, i, w) s390_get_idle_and_iowait(cpu, i, w)
+#define arch_record_iowait_exit(cpu) s390_save_iowait_exit(cpu)
static inline int s390_nohz_delay(int cpu)
{
diff --git a/arch/s390/kernel/vtime.c b/arch/s390/kernel/vtime.c
index 8c34363..f945cbd 100644
--- a/arch/s390/kernel/vtime.c
+++ b/arch/s390/kernel/vtime.c
@@ -155,7 +155,7 @@ EXPORT_SYMBOL_GPL(vtime_account_system);
void __kprobes vtime_stop_cpu(void)
{
struct s390_idle_data *idle = &__get_cpu_var(s390_idle);
- unsigned long long idle_time;
+ unsigned long long idle_enter, idle_exit, iowait_exit;
unsigned long psw_mask;
trace_hardirqs_on();
@@ -171,19 +171,21 @@ void __kprobes vtime_stop_cpu(void)
/* Account time spent with enabled wait psw loaded as idle time. */
idle->sequence++;
smp_wmb();
- idle_time = idle->clock_idle_exit - idle->clock_idle_enter;
+ idle_enter = idle->clock_idle_enter;
+ idle_exit = idle->clock_idle_exit;
+ iowait_exit = idle->clock_iowait_exit;
idle->clock_idle_enter = idle->clock_idle_exit = 0ULL;
- idle->idle_time += idle_time;
+ idle->idle_time += idle_exit - idle_enter;
idle->idle_count++;
- account_idle_time(idle_time);
+ account_idle_and_iowait(idle_enter, iowait_exit, idle_exit);
smp_wmb();
idle->sequence++;
}
-cputime64_t s390_get_idle_time(int cpu)
+void s390_get_idle_and_iowait(int cpu, cputime64_t *reti, cputime64_t *retw)
{
struct s390_idle_data *idle = &per_cpu(s390_idle, cpu);
- unsigned long long now, idle_enter, idle_exit;
+ unsigned long long now, idle_enter, idle_exit, iowait_exit;
unsigned int sequence;
do {
@@ -191,8 +193,32 @@ cputime64_t s390_get_idle_time(int cpu)
sequence = ACCESS_ONCE(idle->sequence);
idle_enter = ACCESS_ONCE(idle->clock_idle_enter);
idle_exit = ACCESS_ONCE(idle->clock_idle_exit);
+ iowait_exit = ACCESS_ONCE(idle->clock_iowait_exit);
} while ((sequence & 1) || (ACCESS_ONCE(idle->sequence) != sequence));
- return idle_enter ? ((idle_exit ?: now) - idle_enter) : 0;
+
+ if (!idle_enter) {
+ *reti = *retw = 0ULL;
+ } else {
+ if (!idle_exit)
+ idle_exit = now;
+ if (nr_iowait_cpu(cpu)) {
+ *retw = idle_exit - idle_enter;
+ *reti = 0ULL;
+ } else if (iowait_exit > idle_enter) {
+ *retw = iowait_exit - idle_enter;
+ *reti = idle_exit - iowait_exit;
+ } else {
+ *retw = 0ULL;
+ *reti = idle_exit - idle_enter;
+ }
+ }
+}
+
+void s390_record_iowait_exit(int cpu)
+{
+ struct s390_idle_data *idle = &per_cpu(s390_idle, cpu);
+
+ idle->clock_iowait_exit = get_tod_clock();
}
/*
diff --git a/fs/proc/stat.c b/fs/proc/stat.c
index 9d231e9..6b23a89 100644
--- a/fs/proc/stat.c
+++ b/fs/proc/stat.c
@@ -19,25 +19,29 @@
#define arch_irq_stat() 0
#endif
-#ifdef arch_idle_time
+#ifdef arch_idle_and_iowait
static cputime64_t get_idle_time(int cpu)
{
- cputime64_t idle;
+ cputime64_t idle, idle_not_accounted_yet, unused;
idle = kcpustat_cpu(cpu).cpustat[CPUTIME_IDLE];
- if (cpu_online(cpu) && !nr_iowait_cpu(cpu))
- idle += arch_idle_time(cpu);
+ if (cpu_online(cpu)) {
+ arch_idle_and_iowait(cpu, &idle_not_accounted_yet, &unused);
+ idle += idle_not_accounted_yet;
+ }
return idle;
}
static cputime64_t get_iowait_time(int cpu)
{
- cputime64_t iowait;
+ cputime64_t iowait, iowait_not_accounted_yet, unused;
iowait = kcpustat_cpu(cpu).cpustat[CPUTIME_IOWAIT];
- if (cpu_online(cpu) && nr_iowait_cpu(cpu))
- iowait += arch_idle_time(cpu);
+ if (cpu_online(cpu)) {
+ arch_idle_and_iowait(cpu, &unused, &iowait_not_accounted_yet);
+ iowait += iowait_not_accounted_yet;
+ }
return iowait;
}
@@ -75,7 +79,7 @@ static u64 get_iowait_time(int cpu)
return iowait;
}
-#endif
+#endif /* arch_idle_and_iowait */
static int show_stat(struct seq_file *p, void *v)
{
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 814ee2e..52abf79 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -4344,8 +4344,12 @@ static inline void iowait_stop(struct rq *rq)
current->in_iowait = 0;
raw_spin_lock(&rq->iowait_lock);
rq->nr_iowait--;
- if (!rq->nr_iowait && rq != this_rq())
+ if (!rq->nr_iowait && rq != this_rq()) {
+#ifdef arch_record_iowait_exit
+ arch_record_iowait_exit(rq->cpu);
+#endif
rq->last_iowait = ktime_get();
+ }
raw_spin_unlock(&rq->iowait_lock);
}
--
1.7.1
next prev parent reply other threads:[~2014-06-26 9:12 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-06-26 9:06 [RFC PATCH 0/8] rework iowait accounting Hidetoshi Seto
2014-06-26 9:08 ` [PATCH 1/8] cputime, sched: record last_iowait Hidetoshi Seto
2014-06-26 9:09 ` [PATCH 2/8] cputime, nohz: handle last_iowait for nohz Hidetoshi Seto
2014-06-26 9:10 ` [PATCH 3/8] cputime: introduce account_idle_and_iowait Hidetoshi Seto
2014-06-26 9:12 ` Hidetoshi Seto [this message]
2014-06-26 9:13 ` [PATCH 5/8] cputime, ia64: update iowait accounting Hidetoshi Seto
2014-06-26 9:14 ` [PATCH 6/8] cputime, ppc: " Hidetoshi Seto
2014-06-26 9:16 ` [PATCH 7/8] cputime: generic iowait accounting for VIRT_CPU_ACCOUNTING Hidetoshi Seto
2014-06-26 9:17 ` [PATCH 8/8] cputime: iowait aware idle tick accounting Hidetoshi Seto
2014-07-07 9:30 ` [RFC PATCH 0/8] rework iowait accounting Peter Zijlstra
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=53ABE3ED.4000901@jp.fujitsu.com \
--to=seto.hidetoshi@jp.fujitsu.com \
--cc=akpm@linux-foundation.org \
--cc=arjan@linux.intel.com \
--cc=fernando_b1@lab.ntt.co.jp \
--cc=fweisbec@gmail.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@kernel.org \
--cc=oleg@redhat.com \
--cc=penguin-kernel@I-love.SAKURA.ne.jp \
--cc=peterz@infradead.org \
--cc=preeti@linux.vnet.ibm.com \
--cc=tglx@linutronix.de \
--cc=vda.linux@googlemail.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).