From baa36046d09ea6dbc122c795566992318663d9eb Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Mon, 18 Jun 2012 17:54:14 +0200 Subject: cputime: Consolidate vtime handling on context switch The archs that implement virtual cputime accounting all flush the cputime of a task when it gets descheduled and sometimes set up some ground initialization for the next task to account its cputime. These archs all put their own hooks in their context switch callbacks and handle the off-case themselves. Consolidate this by creating a new account_switch_vtime() callback called in generic code right after a context switch and that these archs must implement to flush the prev task cputime and initialize the next task cputime related state. Signed-off-by: Frederic Weisbecker Acked-by: Martin Schwidefsky Cc: Tony Luck Cc: Fenghua Yu Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Heiko Carstens Cc: Ingo Molnar Cc: Thomas Gleixner Cc: Peter Zijlstra --- arch/s390/kernel/vtime.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'arch/s390/kernel') diff --git a/arch/s390/kernel/vtime.c b/arch/s390/kernel/vtime.c index 4fc97b40a6e..449ac22cc71 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_vtime(struct task_struct *prev, struct task_struct *next) +void account_switch_vtime(struct task_struct *prev) { struct thread_info *ti; @@ -107,7 +107,7 @@ void account_vtime(struct task_struct *prev, struct task_struct *next) ti = task_thread_info(prev); ti->user_timer = S390_lowcore.user_timer; ti->system_timer = S390_lowcore.system_timer; - ti = task_thread_info(next); + ti = task_thread_info(current); S390_lowcore.user_timer = ti->user_timer; S390_lowcore.system_timer = ti->system_timer; } -- cgit v1.2.3-70-g09d2 From bf9fae9f5e4ca8dce4708812f9ad6281e61df109 Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Sat, 8 Sep 2012 15:23:11 +0200 Subject: cputime: Use a proper subsystem naming for vtime related APIs 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 Cc: Tony Luck Cc: Fenghua Yu Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Heiko Carstens Cc: Martin Schwidefsky Cc: Ingo Molnar Cc: Thomas Gleixner Cc: Peter Zijlstra --- 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(-) (limited to 'arch/s390/kernel') diff --git a/arch/ia64/kernel/time.c b/arch/ia64/kernel/time.c index 6247197b987..16bb6eda879 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 49da7f06e64..39899d7ebda 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 449ac22cc71..cb5093c26d1 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 305f23cd7cf..cab3da3d094 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 bbe5d15d659..ca0944b92f4 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 b70b48b0109..8a59e0abe5f 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 ba144b121f3..21e4dcff18f 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -1764,7 +1764,7 @@ static void finish_task_switch(struct rq *rq, struct task_struct *prev) * Manfred Spraul */ prev_state = prev->state; - account_switch_vtime(prev); + vtime_task_switch(prev); finish_arch_switch(prev); perf_event_task_sched_in(prev, current); finish_lock_switch(rq, prev); diff --git a/kernel/sched/cputime.c b/kernel/sched/cputime.c index 372692bd537..53f5b12f282 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 b73e681df09..d55e3159f92 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()) -- cgit v1.2.3-70-g09d2