From d3759e7184f8f6187e62f8c4e7dcb1f6c47c075a Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Wed, 2 Dec 2020 12:57:31 +0100 Subject: irqtime: Move irqtime entry accounting after irq offset incrementation IRQ time entry is currently accounted before HARDIRQ_OFFSET or SOFTIRQ_OFFSET are incremented. This is convenient to decide to which index the cputime to account is dispatched. Unfortunately it prevents tick_irq_enter() from being called under HARDIRQ_OFFSET because tick_irq_enter() has to be called before the IRQ entry accounting due to the necessary clock catch up. As a result we don't benefit from appropriate lockdep coverage on tick_irq_enter(). To prepare for fixing this, move the IRQ entry cputime accounting after the preempt offset is incremented. This requires the cputime dispatch code to handle the extra offset. Signed-off-by: Frederic Weisbecker Signed-off-by: Thomas Gleixner Acked-by: Peter Zijlstra (Intel) Link: https://lore.kernel.org/r/20201202115732.27827-5-frederic@kernel.org --- include/linux/hardirq.h | 4 ++-- include/linux/vtime.h | 34 ++++++++++++++++++++++++---------- 2 files changed, 26 insertions(+), 12 deletions(-) (limited to 'include/linux') diff --git a/include/linux/hardirq.h b/include/linux/hardirq.h index 754f67ac4326..7c9d6a2d7e90 100644 --- a/include/linux/hardirq.h +++ b/include/linux/hardirq.h @@ -32,9 +32,9 @@ static __always_inline void rcu_irq_enter_check_tick(void) */ #define __irq_enter() \ do { \ - account_irq_enter_time(current); \ preempt_count_add(HARDIRQ_OFFSET); \ lockdep_hardirq_enter(); \ + account_hardirq_enter(current); \ } while (0) /* @@ -62,8 +62,8 @@ void irq_enter_rcu(void); */ #define __irq_exit() \ do { \ + account_hardirq_exit(current); \ lockdep_hardirq_exit(); \ - account_irq_exit_time(current); \ preempt_count_sub(HARDIRQ_OFFSET); \ } while (0) diff --git a/include/linux/vtime.h b/include/linux/vtime.h index 6c9867419615..041d6524d144 100644 --- a/include/linux/vtime.h +++ b/include/linux/vtime.h @@ -83,32 +83,46 @@ static inline void vtime_init_idle(struct task_struct *tsk, int cpu) { } #endif #ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE -extern void vtime_account_irq(struct task_struct *tsk); +extern void vtime_account_irq(struct task_struct *tsk, unsigned int offset); extern void vtime_account_softirq(struct task_struct *tsk); extern void vtime_account_hardirq(struct task_struct *tsk); extern void vtime_flush(struct task_struct *tsk); #else /* !CONFIG_VIRT_CPU_ACCOUNTING_NATIVE */ -static inline void vtime_account_irq(struct task_struct *tsk) { } +static inline void vtime_account_irq(struct task_struct *tsk, unsigned int offset) { } +static inline void vtime_account_softirq(struct task_struct *tsk) { } +static inline void vtime_account_hardirq(struct task_struct *tsk) { } static inline void vtime_flush(struct task_struct *tsk) { } #endif #ifdef CONFIG_IRQ_TIME_ACCOUNTING -extern void irqtime_account_irq(struct task_struct *tsk); +extern void irqtime_account_irq(struct task_struct *tsk, unsigned int offset); #else -static inline void irqtime_account_irq(struct task_struct *tsk) { } +static inline void irqtime_account_irq(struct task_struct *tsk, unsigned int offset) { } #endif -static inline void account_irq_enter_time(struct task_struct *tsk) +static inline void account_softirq_enter(struct task_struct *tsk) { - vtime_account_irq(tsk); - irqtime_account_irq(tsk); + vtime_account_irq(tsk, SOFTIRQ_OFFSET); + irqtime_account_irq(tsk, SOFTIRQ_OFFSET); } -static inline void account_irq_exit_time(struct task_struct *tsk) +static inline void account_softirq_exit(struct task_struct *tsk) { - vtime_account_irq(tsk); - irqtime_account_irq(tsk); + vtime_account_softirq(tsk); + irqtime_account_irq(tsk, 0); +} + +static inline void account_hardirq_enter(struct task_struct *tsk) +{ + vtime_account_irq(tsk, HARDIRQ_OFFSET); + irqtime_account_irq(tsk, HARDIRQ_OFFSET); +} + +static inline void account_hardirq_exit(struct task_struct *tsk) +{ + vtime_account_hardirq(tsk); + irqtime_account_irq(tsk, 0); } #endif /* _LINUX_KERNEL_VTIME_H */ -- cgit v1.2.3