| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <53ABE3ED.4000901@jp.fujitsu.com>
Date: Thu, 26 Jun 2014 18:12:13 +0900
From: Hidetoshi Seto <seto.hidetoshi@...fujitsu.com>
To: linux-kernel@...r.kernel.org
CC: Fernando Luis Vazquez Cao <fernando_b1@....ntt.co.jp>,
Tetsuo Handa <penguin-kernel@...ove.SAKURA.ne.jp>,
Frederic Weisbecker <fweisbec@...il.com>,
Thomas Gleixner <tglx@...utronix.de>,
Ingo Molnar <mingo@...nel.org>,
Peter Zijlstra <peterz@...radead.org>,
Andrew Morton <akpm@...ux-foundation.org>,
Arjan van de Ven <arjan@...ux.intel.com>,
Oleg Nesterov <oleg@...hat.com>,
Preeti U Murthy <preeti@...ux.vnet.ibm.com>,
Denys Vlasenko <vda.linux@...glemail.com>
Subject: [PATCH 4/8] cputime, s390: introduce s390_get_idle_and_iowait
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@...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
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists