[GIT PULL] timers/nohz changes for v3.15
From: Ingo Molnar
Date: Tue Apr 01 2014 - 04:44:49 EST
Linus,
Please pull the latest timers-nohz-for-linus git tree from:
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git timers-nohz-for-linus
# HEAD: 073d8224d299528778e90773becd1e890953443c arch: Remove stub cputime.h headers
The main purpose is to fix a full dynticks bug related to
virtualization, where steal time accounting appears to be zero in
/proc/stat even after a few seconds of competing guests running busy
loops in a same host CPU. It's not a regression though as it was there
since the beginning.
The other commits are preparatory work to fix the bug and various
cleanups.
Thanks,
Ingo
------------------>
Frederic Weisbecker (6):
cputime: Fix nsecs_to_cputime() return type cast
cputime: Default implementation of nsecs -> cputime conversion
cputime: Bring cputime -> nsecs conversion
cputime: Fix jiffies based cputime assumption on steal accounting
sched: Remove needless round trip nsecs <-> tick conversion of steal time
arch: Remove stub cputime.h headers
arch/alpha/include/asm/Kbuild | 1 +
arch/alpha/include/asm/cputime.h | 6 ------
arch/cris/include/asm/Kbuild | 1 +
arch/cris/include/asm/cputime.h | 6 ------
arch/frv/include/asm/Kbuild | 1 +
arch/frv/include/asm/cputime.h | 6 ------
arch/m32r/include/asm/Kbuild | 1 +
arch/m32r/include/asm/cputime.h | 6 ------
arch/microblaze/include/asm/Kbuild | 1 +
arch/microblaze/include/asm/cputime.h | 1 -
arch/mn10300/include/asm/Kbuild | 1 +
arch/mn10300/include/asm/cputime.h | 1 -
arch/score/include/asm/Kbuild | 1 +
arch/score/include/asm/cputime.h | 6 ------
arch/x86/include/asm/Kbuild | 1 +
arch/x86/include/asm/cputime.h | 1 -
drivers/cpufreq/cpufreq_stats.c | 2 +-
drivers/s390/cio/cio.c | 2 +-
fs/proc/stat.c | 2 +-
fs/proc/uptime.c | 2 +-
include/asm-generic/cputime_jiffies.h | 4 +++-
include/asm-generic/cputime_nsecs.h | 5 ++++-
include/linux/cputime.h | 16 ++++++++++++++++
include/linux/kernel_stat.h | 2 +-
include/linux/sched.h | 2 +-
kernel/sched/core.c | 6 ------
kernel/sched/cputime.c | 16 +++++++++++-----
kernel/sched/sched.h | 10 ----------
28 files changed, 48 insertions(+), 62 deletions(-)
delete mode 100644 arch/alpha/include/asm/cputime.h
delete mode 100644 arch/cris/include/asm/cputime.h
delete mode 100644 arch/frv/include/asm/cputime.h
delete mode 100644 arch/m32r/include/asm/cputime.h
delete mode 100644 arch/microblaze/include/asm/cputime.h
delete mode 100644 arch/mn10300/include/asm/cputime.h
delete mode 100644 arch/score/include/asm/cputime.h
delete mode 100644 arch/x86/include/asm/cputime.h
create mode 100644 include/linux/cputime.h
diff --git a/arch/alpha/include/asm/Kbuild b/arch/alpha/include/asm/Kbuild
index 7736f42..96e54be 100644
--- a/arch/alpha/include/asm/Kbuild
+++ b/arch/alpha/include/asm/Kbuild
@@ -1,6 +1,7 @@
generic-y += clkdev.h
+generic-y += cputime.h
generic-y += exec.h
generic-y += hash.h
generic-y += mcs_spinlock.h
diff --git a/arch/alpha/include/asm/cputime.h b/arch/alpha/include/asm/cputime.h
deleted file mode 100644
index 19577fd..0000000
--- a/arch/alpha/include/asm/cputime.h
+++ /dev/null
@@ -1,6 +0,0 @@
-#ifndef __ALPHA_CPUTIME_H
-#define __ALPHA_CPUTIME_H
-
-#include <asm-generic/cputime.h>
-
-#endif /* __ALPHA_CPUTIME_H */
diff --git a/arch/cris/include/asm/Kbuild b/arch/cris/include/asm/Kbuild
index 056027f..afff510 100644
--- a/arch/cris/include/asm/Kbuild
+++ b/arch/cris/include/asm/Kbuild
@@ -5,6 +5,7 @@ header-y += arch-v32/
generic-y += barrier.h
generic-y += clkdev.h
+generic-y += cputime.h
generic-y += exec.h
generic-y += hash.h
generic-y += kvm_para.h
diff --git a/arch/cris/include/asm/cputime.h b/arch/cris/include/asm/cputime.h
deleted file mode 100644
index 4446a65..0000000
--- a/arch/cris/include/asm/cputime.h
+++ /dev/null
@@ -1,6 +0,0 @@
-#ifndef __CRIS_CPUTIME_H
-#define __CRIS_CPUTIME_H
-
-#include <asm-generic/cputime.h>
-
-#endif /* __CRIS_CPUTIME_H */
diff --git a/arch/frv/include/asm/Kbuild b/arch/frv/include/asm/Kbuild
index babb933..87b95eb 100644
--- a/arch/frv/include/asm/Kbuild
+++ b/arch/frv/include/asm/Kbuild
@@ -1,5 +1,6 @@
generic-y += clkdev.h
+generic-y += cputime.h
generic-y += exec.h
generic-y += hash.h
generic-y += mcs_spinlock.h
diff --git a/arch/frv/include/asm/cputime.h b/arch/frv/include/asm/cputime.h
deleted file mode 100644
index f6c373a..0000000
--- a/arch/frv/include/asm/cputime.h
+++ /dev/null
@@ -1,6 +0,0 @@
-#ifndef _ASM_CPUTIME_H
-#define _ASM_CPUTIME_H
-
-#include <asm-generic/cputime.h>
-
-#endif /* _ASM_CPUTIME_H */
diff --git a/arch/m32r/include/asm/Kbuild b/arch/m32r/include/asm/Kbuild
index 5825a35..67779a7 100644
--- a/arch/m32r/include/asm/Kbuild
+++ b/arch/m32r/include/asm/Kbuild
@@ -1,5 +1,6 @@
generic-y += clkdev.h
+generic-y += cputime.h
generic-y += exec.h
generic-y += hash.h
generic-y += mcs_spinlock.h
diff --git a/arch/m32r/include/asm/cputime.h b/arch/m32r/include/asm/cputime.h
deleted file mode 100644
index 0a47550..0000000
--- a/arch/m32r/include/asm/cputime.h
+++ /dev/null
@@ -1,6 +0,0 @@
-#ifndef __M32R_CPUTIME_H
-#define __M32R_CPUTIME_H
-
-#include <asm-generic/cputime.h>
-
-#endif /* __M32R_CPUTIME_H */
diff --git a/arch/microblaze/include/asm/Kbuild b/arch/microblaze/include/asm/Kbuild
index 1f590ab..c98ed95 100644
--- a/arch/microblaze/include/asm/Kbuild
+++ b/arch/microblaze/include/asm/Kbuild
@@ -1,6 +1,7 @@
generic-y += barrier.h
generic-y += clkdev.h
+generic-y += cputime.h
generic-y += exec.h
generic-y += hash.h
generic-y += mcs_spinlock.h
diff --git a/arch/microblaze/include/asm/cputime.h b/arch/microblaze/include/asm/cputime.h
deleted file mode 100644
index 6d68ad7..0000000
--- a/arch/microblaze/include/asm/cputime.h
+++ /dev/null
@@ -1 +0,0 @@
-#include <asm-generic/cputime.h>
diff --git a/arch/mn10300/include/asm/Kbuild b/arch/mn10300/include/asm/Kbuild
index cbc6b9b..654d5ba 100644
--- a/arch/mn10300/include/asm/Kbuild
+++ b/arch/mn10300/include/asm/Kbuild
@@ -1,6 +1,7 @@
generic-y += barrier.h
generic-y += clkdev.h
+generic-y += cputime.h
generic-y += exec.h
generic-y += hash.h
generic-y += mcs_spinlock.h
diff --git a/arch/mn10300/include/asm/cputime.h b/arch/mn10300/include/asm/cputime.h
deleted file mode 100644
index 6d68ad7..0000000
--- a/arch/mn10300/include/asm/cputime.h
+++ /dev/null
@@ -1 +0,0 @@
-#include <asm-generic/cputime.h>
diff --git a/arch/score/include/asm/Kbuild b/arch/score/include/asm/Kbuild
index 4630cf2..2f947ab 100644
--- a/arch/score/include/asm/Kbuild
+++ b/arch/score/include/asm/Kbuild
@@ -4,6 +4,7 @@ header-y +=
generic-y += barrier.h
generic-y += clkdev.h
+generic-y += cputime.h
generic-y += hash.h
generic-y += mcs_spinlock.h
generic-y += preempt.h
diff --git a/arch/score/include/asm/cputime.h b/arch/score/include/asm/cputime.h
deleted file mode 100644
index 1fced99..0000000
--- a/arch/score/include/asm/cputime.h
+++ /dev/null
@@ -1,6 +0,0 @@
-#ifndef _ASM_SCORE_CPUTIME_H
-#define _ASM_SCORE_CPUTIME_H
-
-#include <asm-generic/cputime.h>
-
-#endif /* _ASM_SCORE_CPUTIME_H */
diff --git a/arch/x86/include/asm/Kbuild b/arch/x86/include/asm/Kbuild
index a8fee07..4acddc4 100644
--- a/arch/x86/include/asm/Kbuild
+++ b/arch/x86/include/asm/Kbuild
@@ -5,4 +5,5 @@ genhdr-y += unistd_64.h
genhdr-y += unistd_x32.h
generic-y += clkdev.h
+generic-y += cputime.h
generic-y += mcs_spinlock.h
diff --git a/arch/x86/include/asm/cputime.h b/arch/x86/include/asm/cputime.h
deleted file mode 100644
index 6d68ad7..0000000
--- a/arch/x86/include/asm/cputime.h
+++ /dev/null
@@ -1 +0,0 @@
-#include <asm-generic/cputime.h>
diff --git a/drivers/cpufreq/cpufreq_stats.c b/drivers/cpufreq/cpufreq_stats.c
index 5793e14..79911a2 100644
--- a/drivers/cpufreq/cpufreq_stats.c
+++ b/drivers/cpufreq/cpufreq_stats.c
@@ -13,7 +13,7 @@
#include <linux/cpufreq.h>
#include <linux/module.h>
#include <linux/slab.h>
-#include <asm/cputime.h>
+#include <linux/cputime.h>
static spinlock_t cpufreq_stats_lock;
diff --git a/drivers/s390/cio/cio.c b/drivers/s390/cio/cio.c
index 88e35d8..5154513 100644
--- a/drivers/s390/cio/cio.c
+++ b/drivers/s390/cio/cio.c
@@ -28,7 +28,7 @@
#include <asm/chpid.h>
#include <asm/airq.h>
#include <asm/isc.h>
-#include <asm/cputime.h>
+#include <linux/cputime.h>
#include <asm/fcx.h>
#include <asm/nmi.h>
#include <asm/crw.h>
diff --git a/fs/proc/stat.c b/fs/proc/stat.c
index 6f599c6..9d231e9 100644
--- a/fs/proc/stat.c
+++ b/fs/proc/stat.c
@@ -9,7 +9,7 @@
#include <linux/slab.h>
#include <linux/time.h>
#include <linux/irqnr.h>
-#include <asm/cputime.h>
+#include <linux/cputime.h>
#include <linux/tick.h>
#ifndef arch_irq_stat_cpu
diff --git a/fs/proc/uptime.c b/fs/proc/uptime.c
index 7141b8d..33de567 100644
--- a/fs/proc/uptime.c
+++ b/fs/proc/uptime.c
@@ -5,7 +5,7 @@
#include <linux/seq_file.h>
#include <linux/time.h>
#include <linux/kernel_stat.h>
-#include <asm/cputime.h>
+#include <linux/cputime.h>
static int uptime_proc_show(struct seq_file *m, void *v)
{
diff --git a/include/asm-generic/cputime_jiffies.h b/include/asm-generic/cputime_jiffies.h
index 272ecba..d5cb78f5 100644
--- a/include/asm-generic/cputime_jiffies.h
+++ b/include/asm-generic/cputime_jiffies.h
@@ -15,8 +15,10 @@ typedef u64 __nocast cputime64_t;
/*
- * Convert nanoseconds to cputime
+ * Convert nanoseconds <-> cputime
*/
+#define cputime_to_nsecs(__ct) \
+ jiffies_to_nsecs(cputime_to_jiffies(__ct))
#define nsecs_to_cputime64(__nsec) \
jiffies64_to_cputime64(nsecs_to_jiffies64(__nsec))
#define nsecs_to_cputime(__nsec) \
diff --git a/include/asm-generic/cputime_nsecs.h b/include/asm-generic/cputime_nsecs.h
index 2c9e62c..4e81760 100644
--- a/include/asm-generic/cputime_nsecs.h
+++ b/include/asm-generic/cputime_nsecs.h
@@ -44,7 +44,10 @@ typedef u64 __nocast cputime64_t;
/*
* Convert cputime <-> nanoseconds
*/
-#define nsecs_to_cputime(__nsecs) ((__force u64)(__nsecs))
+#define cputime_to_nsecs(__ct) \
+ (__force u64)(__ct)
+#define nsecs_to_cputime(__nsecs) \
+ (__force cputime_t)(__nsecs)
/*
diff --git a/include/linux/cputime.h b/include/linux/cputime.h
new file mode 100644
index 0000000..f2eb2ee
--- /dev/null
+++ b/include/linux/cputime.h
@@ -0,0 +1,16 @@
+#ifndef __LINUX_CPUTIME_H
+#define __LINUX_CPUTIME_H
+
+#include <asm/cputime.h>
+
+#ifndef cputime_to_nsecs
+# define cputime_to_nsecs(__ct) \
+ (cputime_to_usecs(__ct) * NSEC_PER_USEC)
+#endif
+
+#ifndef nsecs_to_cputime
+# define nsecs_to_cputime(__nsecs) \
+ usecs_to_cputime((__nsecs) / NSEC_PER_USEC)
+#endif
+
+#endif /* __LINUX_CPUTIME_H */
diff --git a/include/linux/kernel_stat.h b/include/linux/kernel_stat.h
index 51c72be..d7c6131 100644
--- a/include/linux/kernel_stat.h
+++ b/include/linux/kernel_stat.h
@@ -9,7 +9,7 @@
#include <linux/sched.h>
#include <linux/vtime.h>
#include <asm/irq.h>
-#include <asm/cputime.h>
+#include <linux/cputime.h>
/*
* 'kernel_stat.h' contains the definitions needed for doing
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 68a0e84..1ac566c 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -27,7 +27,7 @@ struct sched_param {
#include <asm/page.h>
#include <asm/ptrace.h>
-#include <asm/cputime.h>
+#include <linux/cputime.h>
#include <linux/smp.h>
#include <linux/sem.h>
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index b46131e..b14a188 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -823,19 +823,13 @@ static void update_rq_clock_task(struct rq *rq, s64 delta)
#endif
#ifdef CONFIG_PARAVIRT_TIME_ACCOUNTING
if (static_key_false((¶virt_steal_rq_enabled))) {
- u64 st;
-
steal = paravirt_steal_clock(cpu_of(rq));
steal -= rq->prev_steal_time_rq;
if (unlikely(steal > delta))
steal = delta;
- st = steal_ticks(steal);
- steal = st * TICK_NSEC;
-
rq->prev_steal_time_rq += steal;
-
delta -= steal;
}
#endif
diff --git a/kernel/sched/cputime.c b/kernel/sched/cputime.c
index 9994791..c91b097 100644
--- a/kernel/sched/cputime.c
+++ b/kernel/sched/cputime.c
@@ -258,16 +258,22 @@ static __always_inline bool steal_account_process_tick(void)
{
#ifdef CONFIG_PARAVIRT
if (static_key_false(¶virt_steal_enabled)) {
- u64 steal, st = 0;
+ u64 steal;
+ cputime_t steal_ct;
steal = paravirt_steal_clock(smp_processor_id());
steal -= this_rq()->prev_steal_time;
- st = steal_ticks(steal);
- this_rq()->prev_steal_time += st * TICK_NSEC;
+ /*
+ * cputime_t may be less precise than nsecs (eg: if it's
+ * based on jiffies). Lets cast the result to cputime
+ * granularity and account the rest on the next rounds.
+ */
+ steal_ct = nsecs_to_cputime(steal);
+ this_rq()->prev_steal_time += cputime_to_nsecs(steal_ct);
- account_steal_time(st);
- return st;
+ account_steal_time(steal_ct);
+ return steal_ct;
}
#endif
return false;
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index c2119fd..5ec9910 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -1214,16 +1214,6 @@ extern void update_idle_cpu_load(struct rq *this_rq);
extern void init_task_runnable_average(struct task_struct *p);
-#ifdef CONFIG_PARAVIRT
-static inline u64 steal_ticks(u64 steal)
-{
- if (unlikely(steal > NSEC_PER_SEC))
- return div_u64(steal, TICK_NSEC);
-
- return __iter_div_u64_rem(steal, TICK_NSEC, &steal);
-}
-#endif
-
static inline void inc_nr_running(struct rq *rq)
{
rq->nr_running++;
--
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