From: Frederic Weisbecker <fweisbec@gmail.com>
To: LKML <linux-kernel@vger.kernel.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>,
Steven Rostedt <rostedt@goodmis.org>,
"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
Ingo Molnar <mingo@kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
Peter Zijlstra <peterz@infradead.org>,
Borislav Petkov <bp@alien8.de>,
Li Zhong <zhong@linux.vnet.ibm.com>,
Mike Galbraith <efault@gmx.de>, Kevin Hilman <khilman@linaro.org>
Subject: [PATCH 16/18] vtime: Optimize full dynticks accounting off case with static keys
Date: Wed, 17 Jul 2013 18:44:29 +0200 [thread overview]
Message-ID: <1374079471-3129-17-git-send-email-fweisbec@gmail.com> (raw)
In-Reply-To: <1374079471-3129-1-git-send-email-fweisbec@gmail.com>
If no CPU is in the full dynticks range, we can avoid the full
dynticks cputime accounting through generic vtime along with its
overhead and use the traditional tick based accounting instead.
Let's do this and nope the off case with static keys.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Kevin Hilman <khilman@linaro.org>
---
include/linux/context_tracking.h | 6 +--
include/linux/vtime.h | 70 +++++++++++++++++++++++++++++++++-----
kernel/sched/cputime.c | 22 ++----------
3 files changed, 67 insertions(+), 31 deletions(-)
diff --git a/include/linux/context_tracking.h b/include/linux/context_tracking.h
index 8635dbb..07cdf93 100644
--- a/include/linux/context_tracking.h
+++ b/include/linux/context_tracking.h
@@ -66,8 +66,7 @@ static inline void context_tracking_task_switch(struct task_struct *prev,
#ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
static inline void guest_enter(void)
{
- if (static_key_false(&context_tracking_enabled) &&
- vtime_accounting_enabled())
+ if (vtime_accounting_enabled())
vtime_guest_enter(current);
else
current->flags |= PF_VCPU;
@@ -75,8 +74,7 @@ static inline void guest_enter(void)
static inline void guest_exit(void)
{
- if (static_key_false(&context_tracking_enabled) &&
- vtime_accounting_enabled())
+ if (vtime_accounting_enabled())
vtime_guest_exit(current);
else
current->flags &= ~PF_VCPU;
diff --git a/include/linux/vtime.h b/include/linux/vtime.h
index 2ad0739..f5b72b3 100644
--- a/include/linux/vtime.h
+++ b/include/linux/vtime.h
@@ -1,22 +1,68 @@
#ifndef _LINUX_KERNEL_VTIME_H
#define _LINUX_KERNEL_VTIME_H
+#include <linux/context_tracking_state.h>
#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
#include <asm/vtime.h>
#endif
+
struct task_struct;
+/*
+ * vtime_accounting_enabled() definitions/declarations
+ */
+#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
+static inline bool vtime_accounting_enabled(void) { return true; }
+#endif /* CONFIG_VIRT_CPU_ACCOUNTING_NATIVE */
+
+#ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
+static inline bool vtime_accounting_enabled(void)
+{
+ if (static_key_false(&context_tracking_enabled)) {
+ if (context_tracking_active())
+ return true;
+ }
+
+ return false;
+}
+#endif /* CONFIG_VIRT_CPU_ACCOUNTING_GEN */
+
+#ifndef CONFIG_VIRT_CPU_ACCOUNTING
+static inline bool vtime_accounting_enabled(void) { return false; }
+#endif /* !CONFIG_VIRT_CPU_ACCOUNTING */
+
+
+/*
+ * Common vtime APIs
+ */
#ifdef CONFIG_VIRT_CPU_ACCOUNTING
+
+#ifdef __ARCH_HAS_VTIME_TASK_SWITCH
extern void vtime_task_switch(struct task_struct *prev);
+#else
+extern void vtime_common_task_switch(struct task_struct *prev);
+static inline void vtime_task_switch(struct task_struct *prev)
+{
+ if (vtime_accounting_enabled())
+ vtime_common_task_switch(prev);
+}
+#endif /* __ARCH_HAS_VTIME_TASK_SWITCH */
+
extern void vtime_account_system(struct task_struct *tsk);
extern void vtime_account_idle(struct task_struct *tsk);
extern void vtime_account_user(struct task_struct *tsk);
-extern void vtime_account_irq_enter(struct task_struct *tsk);
-#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
-static inline bool vtime_accounting_enabled(void) { return true; }
-#endif
+#ifdef __ARCH_HAS_VTIME_ACCOUNT
+extern void vtime_account_irq_enter(struct task_struct *tsk);
+#else
+extern void vtime_common_account_irq_enter(struct task_struct *tsk);
+static inline void vtime_account_irq_enter(struct task_struct *tsk)
+{
+ if (vtime_accounting_enabled())
+ vtime_common_account_irq_enter(tsk);
+}
+#endif /* __ARCH_HAS_VTIME_ACCOUNT */
#else /* !CONFIG_VIRT_CPU_ACCOUNTING */
@@ -24,14 +70,20 @@ static inline void vtime_task_switch(struct task_struct *prev) { }
static inline void vtime_account_system(struct task_struct *tsk) { }
static inline void vtime_account_user(struct task_struct *tsk) { }
static inline void vtime_account_irq_enter(struct task_struct *tsk) { }
-static inline bool vtime_accounting_enabled(void) { return false; }
-#endif
+#endif /* !CONFIG_VIRT_CPU_ACCOUNTING */
#ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
extern void arch_vtime_task_switch(struct task_struct *tsk);
-extern void vtime_account_irq_exit(struct task_struct *tsk);
-extern bool vtime_accounting_enabled(void);
+extern void vtime_gen_account_irq_exit(struct task_struct *tsk);
+
+static inline void vtime_account_irq_exit(struct task_struct *tsk)
+{
+ if (vtime_accounting_enabled())
+ vtime_gen_account_irq_exit(tsk);
+}
+
extern void vtime_user_enter(struct task_struct *tsk);
+
static inline void vtime_user_exit(struct task_struct *tsk)
{
vtime_account_user(tsk);
@@ -39,7 +91,7 @@ static inline void vtime_user_exit(struct task_struct *tsk)
extern void vtime_guest_enter(struct task_struct *tsk);
extern void vtime_guest_exit(struct task_struct *tsk);
extern void vtime_init_idle(struct task_struct *tsk, int cpu);
-#else
+#else /* !CONFIG_VIRT_CPU_ACCOUNTING_GEN */
static inline void vtime_account_irq_exit(struct task_struct *tsk)
{
/* On hard|softirq exit we always account to hard|softirq cputime */
diff --git a/kernel/sched/cputime.c b/kernel/sched/cputime.c
index b62d5c0..0831b06 100644
--- a/kernel/sched/cputime.c
+++ b/kernel/sched/cputime.c
@@ -378,11 +378,8 @@ static inline void irqtime_account_process_tick(struct task_struct *p, int user_
#ifdef CONFIG_VIRT_CPU_ACCOUNTING
#ifndef __ARCH_HAS_VTIME_TASK_SWITCH
-void vtime_task_switch(struct task_struct *prev)
+void vtime_common_task_switch(struct task_struct *prev)
{
- if (!vtime_accounting_enabled())
- return;
-
if (is_idle_task(prev))
vtime_account_idle(prev);
else
@@ -404,11 +401,8 @@ void vtime_task_switch(struct task_struct *prev)
* vtime_account().
*/
#ifndef __ARCH_HAS_VTIME_ACCOUNT
-void vtime_account_irq_enter(struct task_struct *tsk)
+void vtime_common_account_irq_enter(struct task_struct *tsk)
{
- if (!vtime_accounting_enabled())
- return;
-
if (!in_interrupt()) {
/*
* If we interrupted user, context_tracking_in_user()
@@ -428,7 +422,7 @@ void vtime_account_irq_enter(struct task_struct *tsk)
}
vtime_account_system(tsk);
}
-EXPORT_SYMBOL_GPL(vtime_account_irq_enter);
+EXPORT_SYMBOL_GPL(vtime_common_account_irq_enter);
#endif /* __ARCH_HAS_VTIME_ACCOUNT */
#endif /* CONFIG_VIRT_CPU_ACCOUNTING */
@@ -669,11 +663,8 @@ void vtime_account_system(struct task_struct *tsk)
write_sequnlock(&tsk->vtime_seqlock);
}
-void vtime_account_irq_exit(struct task_struct *tsk)
+void vtime_gen_account_irq_exit(struct task_struct *tsk)
{
- if (!vtime_accounting_enabled())
- return;
-
write_seqlock(&tsk->vtime_seqlock);
if (context_tracking_in_user())
tsk->vtime_snap_whence = VTIME_USER;
@@ -732,11 +723,6 @@ void vtime_account_idle(struct task_struct *tsk)
account_idle_time(delta_cpu);
}
-bool vtime_accounting_enabled(void)
-{
- return context_tracking_active();
-}
-
void arch_vtime_task_switch(struct task_struct *prev)
{
write_seqlock(&prev->vtime_seqlock);
--
1.7.5.4
next prev parent reply other threads:[~2013-07-17 16:45 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-07-17 16:44 [PATCH 00/18] nohz patches for 3.12 preview Frederic Weisbecker
2013-07-17 16:44 ` [PATCH 01/18] nohz: Do not warn about unstable tsc unless user uses nohz_full Frederic Weisbecker
2013-07-17 16:44 ` [PATCH 02/18] nohz: fix compile warning in tick_nohz_init() Frederic Weisbecker
2013-07-17 16:44 ` [PATCH 03/18] sched: Consolidate open coded preemptible() checks Frederic Weisbecker
2013-07-17 16:44 ` [PATCH 04/18] context_tracing: Fix guest accounting with native vtime Frederic Weisbecker
2013-07-17 16:44 ` [PATCH 05/18] vtime: Update a few comments Frederic Weisbecker
2013-07-17 17:57 ` Steven Rostedt
2013-07-18 21:30 ` Frederic Weisbecker
2013-07-17 16:44 ` [PATCH 06/18] context_tracking: Fix runtime CPU off-case Frederic Weisbecker
2013-07-17 16:44 ` [PATCH 07/18] nohz: Selectively enable context tracking on full dynticks CPUs Frederic Weisbecker
2013-07-17 18:27 ` Steven Rostedt
2013-07-18 22:13 ` Frederic Weisbecker
2013-07-18 22:51 ` Steven Rostedt
2013-07-19 14:19 ` Frederic Weisbecker
2013-07-17 16:44 ` [PATCH 08/18] context_tracking: Ground setup for static key use Frederic Weisbecker
2013-07-17 16:44 ` [PATCH 09/18] context_tracking: Optimize main APIs off case with static key Frederic Weisbecker
2013-07-17 16:44 ` [PATCH 10/18] context_tracking: Optimize context switch off case with static keys Frederic Weisbecker
2013-07-17 16:44 ` [PATCH 11/18] context_tracking: User/kernel broundary cross trace events Frederic Weisbecker
2013-07-17 16:44 ` [PATCH 12/18] vtime: Remove a few unneeded generic vtime state checks Frederic Weisbecker
2013-07-17 16:44 ` [PATCH 13/18] vtime: Fix racy cputime delta update Frederic Weisbecker
2013-07-17 16:44 ` [PATCH 14/18] context_tracking: Split low level state headers Frederic Weisbecker
2013-07-17 16:44 ` [PATCH 15/18] vtime: Describe overriden functions in dedicated arch headers Frederic Weisbecker
2013-07-17 16:44 ` Frederic Weisbecker [this message]
2013-07-17 16:44 ` [PATCH 17/18] vtime: Always scale generic vtime accounting results Frederic Weisbecker
2013-07-17 16:44 ` [PATCH 18/18] vtime: Always debug check snapshot source _before_ updating it Frederic Weisbecker
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