[PATCH 1/6] cputime: Use a proper subsystem naming for vtime related APIs

From: Frederic Weisbecker
Date: Mon Sep 10 2012 - 15:43:23 EST


Use a naming based on vtime as a prefix for virtual based
cputime accounting APIs:

- account_system_vtime() -> vtime_account()
- account_switch_vtime() -> vtime_task_switch()

It makes it easier to allow for further declension such
as vtime_account_system(), vtime_account_idle(), ... if we
want to find out the context we account to from generic code.

This also make it better to know on which subsystem these APIs
refer to.

Signed-off-by: Frederic Weisbecker <fweisbec@xxxxxxxxx>
Cc: Tony Luck <tony.luck@xxxxxxxxx>
Cc: Fenghua Yu <fenghua.yu@xxxxxxxxx>
Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Cc: Heiko Carstens <heiko.carstens@xxxxxxxxxx>
Cc: Martin Schwidefsky <schwidefsky@xxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
---
arch/ia64/kernel/time.c | 6 +++---
arch/powerpc/kernel/time.c | 10 +++++-----
arch/s390/kernel/vtime.c | 6 +++---
include/linux/hardirq.h | 8 ++++----
include/linux/kernel_stat.h | 4 ++--
include/linux/kvm_host.h | 4 ++--
kernel/sched/core.c | 2 +-
kernel/sched/cputime.c | 8 ++++----
kernel/softirq.c | 6 +++---
9 files changed, 27 insertions(+), 27 deletions(-)

diff --git a/arch/ia64/kernel/time.c b/arch/ia64/kernel/time.c
index 6247197..16bb6ed 100644
--- a/arch/ia64/kernel/time.c
+++ b/arch/ia64/kernel/time.c
@@ -88,7 +88,7 @@ extern cputime_t cycle_to_cputime(u64 cyc);
* accumulated times to the current process, and to prepare accounting on
* the next process.
*/
-void account_switch_vtime(struct task_struct *prev)
+void vtime_task_switch(struct task_struct *prev)
{
struct thread_info *pi = task_thread_info(prev);
struct thread_info *ni = task_thread_info(current);
@@ -116,7 +116,7 @@ void account_switch_vtime(struct task_struct *prev)
* Account time for a transition between system, hard irq or soft irq state.
* Note that this function is called with interrupts enabled.
*/
-void account_system_vtime(struct task_struct *tsk)
+void vtime_account(struct task_struct *tsk)
{
struct thread_info *ti = task_thread_info(tsk);
unsigned long flags;
@@ -138,7 +138,7 @@ void account_system_vtime(struct task_struct *tsk)

local_irq_restore(flags);
}
-EXPORT_SYMBOL_GPL(account_system_vtime);
+EXPORT_SYMBOL_GPL(vtime_account);

/*
* Called from the timer interrupt handler to charge accumulated user time
diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c
index 49da7f0..39899d7 100644
--- a/arch/powerpc/kernel/time.c
+++ b/arch/powerpc/kernel/time.c
@@ -291,7 +291,7 @@ static inline u64 calculate_stolen_time(u64 stop_tb)
* Account time for a transition between system, hard irq
* or soft irq state.
*/
-void account_system_vtime(struct task_struct *tsk)
+void vtime_account(struct task_struct *tsk)
{
u64 now, nowscaled, delta, deltascaled;
unsigned long flags;
@@ -343,14 +343,14 @@ void account_system_vtime(struct task_struct *tsk)
}
local_irq_restore(flags);
}
-EXPORT_SYMBOL_GPL(account_system_vtime);
+EXPORT_SYMBOL_GPL(vtime_account);

/*
* Transfer the user and system times accumulated in the paca
* by the exception entry and exit code to the generic process
* user and system time records.
* Must be called with interrupts disabled.
- * Assumes that account_system_vtime() has been called recently
+ * Assumes that vtime_account() has been called recently
* (i.e. since the last entry from usermode) so that
* get_paca()->user_time_scaled is up to date.
*/
@@ -366,9 +366,9 @@ void account_process_tick(struct task_struct *tsk, int user_tick)
account_user_time(tsk, utime, utimescaled);
}

-void account_switch_vtime(struct task_struct *prev)
+void vtime_task_switch(struct task_struct *prev)
{
- account_system_vtime(prev);
+ vtime_account(prev);
account_process_tick(prev, 0);
}

diff --git a/arch/s390/kernel/vtime.c b/arch/s390/kernel/vtime.c
index 449ac22..cb5093c 100644
--- a/arch/s390/kernel/vtime.c
+++ b/arch/s390/kernel/vtime.c
@@ -99,7 +99,7 @@ static int do_account_vtime(struct task_struct *tsk, int hardirq_offset)
return virt_timer_forward(user + system);
}

-void account_switch_vtime(struct task_struct *prev)
+void vtime_task_switch(struct task_struct *prev)
{
struct thread_info *ti;

@@ -122,7 +122,7 @@ void account_process_tick(struct task_struct *tsk, int user_tick)
* Update process times based on virtual cpu times stored by entry.S
* to the lowcore fields user_timer, system_timer & steal_clock.
*/
-void account_system_vtime(struct task_struct *tsk)
+void vtime_account(struct task_struct *tsk)
{
struct thread_info *ti = task_thread_info(tsk);
u64 timer, system;
@@ -138,7 +138,7 @@ void account_system_vtime(struct task_struct *tsk)

virt_timer_forward(system);
}
-EXPORT_SYMBOL_GPL(account_system_vtime);
+EXPORT_SYMBOL_GPL(vtime_account);

void __kprobes vtime_stop_cpu(void)
{
diff --git a/include/linux/hardirq.h b/include/linux/hardirq.h
index 305f23c..cab3da3 100644
--- a/include/linux/hardirq.h
+++ b/include/linux/hardirq.h
@@ -132,11 +132,11 @@ extern void synchronize_irq(unsigned int irq);
struct task_struct;

#if !defined(CONFIG_VIRT_CPU_ACCOUNTING) && !defined(CONFIG_IRQ_TIME_ACCOUNTING)
-static inline void account_system_vtime(struct task_struct *tsk)
+static inline void vtime_account(struct task_struct *tsk)
{
}
#else
-extern void account_system_vtime(struct task_struct *tsk);
+extern void vtime_account(struct task_struct *tsk);
#endif

#if defined(CONFIG_TINY_RCU) || defined(CONFIG_TINY_PREEMPT_RCU)
@@ -162,7 +162,7 @@ extern void rcu_nmi_exit(void);
*/
#define __irq_enter() \
do { \
- account_system_vtime(current); \
+ vtime_account(current); \
add_preempt_count(HARDIRQ_OFFSET); \
trace_hardirq_enter(); \
} while (0)
@@ -178,7 +178,7 @@ extern void irq_enter(void);
#define __irq_exit() \
do { \
trace_hardirq_exit(); \
- account_system_vtime(current); \
+ vtime_account(current); \
sub_preempt_count(HARDIRQ_OFFSET); \
} while (0)

diff --git a/include/linux/kernel_stat.h b/include/linux/kernel_stat.h
index bbe5d15..ca0944b 100644
--- a/include/linux/kernel_stat.h
+++ b/include/linux/kernel_stat.h
@@ -131,9 +131,9 @@ extern void account_steal_ticks(unsigned long ticks);
extern void account_idle_ticks(unsigned long ticks);

#ifdef CONFIG_VIRT_CPU_ACCOUNTING
-extern void account_switch_vtime(struct task_struct *prev);
+extern void vtime_task_switch(struct task_struct *prev);
#else
-static inline void account_switch_vtime(struct task_struct *prev) { }
+static inline void vtime_task_switch(struct task_struct *prev) { }
#endif

#endif /* _LINUX_KERNEL_STAT_H */
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index b70b48b..8a59e0a 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -685,7 +685,7 @@ static inline int kvm_deassign_device(struct kvm *kvm,
static inline void kvm_guest_enter(void)
{
BUG_ON(preemptible());
- account_system_vtime(current);
+ vtime_account(current);
current->flags |= PF_VCPU;
/* KVM does not hold any references to rcu protected data when it
* switches CPU into a guest mode. In fact switching to a guest mode
@@ -699,7 +699,7 @@ static inline void kvm_guest_enter(void)

static inline void kvm_guest_exit(void)
{
- account_system_vtime(current);
+ vtime_account(current);
current->flags &= ~PF_VCPU;
}

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index c46a011..fc62423 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -1796,7 +1796,7 @@ static void finish_task_switch(struct rq *rq, struct task_struct *prev)
* Manfred Spraul <manfred@xxxxxxxxxxxxxxxx>
*/
prev_state = prev->state;
- account_switch_vtime(prev);
+ vtime_task_switch(prev);
finish_arch_switch(prev);
#ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW
local_irq_disable();
diff --git a/kernel/sched/cputime.c b/kernel/sched/cputime.c
index 372692b..53f5b12 100644
--- a/kernel/sched/cputime.c
+++ b/kernel/sched/cputime.c
@@ -10,11 +10,11 @@

/*
* There are no locks covering percpu hardirq/softirq time.
- * They are only modified in account_system_vtime, on corresponding CPU
+ * They are only modified in vtime_account, on corresponding CPU
* with interrupts disabled. So, writes are safe.
* They are read and saved off onto struct rq in update_rq_clock().
* This may result in other CPU reading this CPU's irq time and can
- * race with irq/account_system_vtime on this CPU. We would either get old
+ * race with irq/vtime_account on this CPU. We would either get old
* or new value with a side effect of accounting a slice of irq time to wrong
* task when irq is in progress while we read rq->clock. That is a worthy
* compromise in place of having locks on each irq in account_system_time.
@@ -43,7 +43,7 @@ DEFINE_PER_CPU(seqcount_t, irq_time_seq);
* Called before incrementing preempt_count on {soft,}irq_enter
* and before decrementing preempt_count on {soft,}irq_exit.
*/
-void account_system_vtime(struct task_struct *curr)
+void vtime_account(struct task_struct *curr)
{
unsigned long flags;
s64 delta;
@@ -73,7 +73,7 @@ void account_system_vtime(struct task_struct *curr)
irq_time_write_end();
local_irq_restore(flags);
}
-EXPORT_SYMBOL_GPL(account_system_vtime);
+EXPORT_SYMBOL_GPL(vtime_account);

static int irqtime_account_hi_update(void)
{
diff --git a/kernel/softirq.c b/kernel/softirq.c
index b73e681..d55e315 100644
--- a/kernel/softirq.c
+++ b/kernel/softirq.c
@@ -220,7 +220,7 @@ asmlinkage void __do_softirq(void)
current->flags &= ~PF_MEMALLOC;

pending = local_softirq_pending();
- account_system_vtime(current);
+ vtime_account(current);

__local_bh_disable((unsigned long)__builtin_return_address(0),
SOFTIRQ_OFFSET);
@@ -271,7 +271,7 @@ restart:

lockdep_softirq_exit();

- account_system_vtime(current);
+ vtime_account(current);
__local_bh_enable(SOFTIRQ_OFFSET);
tsk_restore_flags(current, old_flags, PF_MEMALLOC);
}
@@ -340,7 +340,7 @@ static inline void invoke_softirq(void)
*/
void irq_exit(void)
{
- account_system_vtime(current);
+ vtime_account(current);
trace_hardirq_exit();
sub_preempt_count(IRQ_EXIT_OFFSET);
if (!in_interrupt() && local_softirq_pending())
--
1.7.5.4

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