From dcbf832e5823156e8f155359b47bd108cac8ad68 Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Fri, 5 Oct 2012 23:07:19 +0200 Subject: vtime: Gather vtime declarations to their own header file These APIs are scattered around and are going to expand a bit. Let's create a dedicated header file for sanity. Signed-off-by: Frederic Weisbecker Cc: Peter Zijlstra Cc: Ingo Molnar Cc: Thomas Gleixner Cc: Steven Rostedt Cc: Paul Gortmaker --- include/linux/kernel_stat.h | 9 +-------- 1 file changed, 1 insertion(+), 8 deletions(-) (limited to 'include/linux/kernel_stat.h') diff --git a/include/linux/kernel_stat.h b/include/linux/kernel_stat.h index 36d12f0884c3..1865b1f29770 100644 --- a/include/linux/kernel_stat.h +++ b/include/linux/kernel_stat.h @@ -7,6 +7,7 @@ #include #include #include +#include #include #include @@ -130,12 +131,4 @@ extern void account_process_tick(struct task_struct *, int user); extern void account_steal_ticks(unsigned long ticks); extern void account_idle_ticks(unsigned long ticks); -#ifdef CONFIG_VIRT_CPU_ACCOUNTING -extern void vtime_task_switch(struct task_struct *prev); -extern void vtime_account_system(struct task_struct *tsk); -extern void vtime_account_idle(struct task_struct *tsk); -#else -static inline void vtime_task_switch(struct task_struct *prev) { } -#endif - #endif /* _LINUX_KERNEL_STAT_H */ -- cgit v1.2.3 From bcebdf846522056a84ba0b0cba5f5413868c9394 Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Tue, 13 Nov 2012 23:51:06 +0100 Subject: vtime: Explicitly account pending user time on process tick All vtime implementations just flush the user time on process tick. Consolidate that in generic code by calling a user time accounting helper. This avoids an indirect call in ia64 and prepare to also consolidate vtime context switch code. Signed-off-by: Frederic Weisbecker Reviewed-by: Steven Rostedt Cc: Peter Zijlstra Cc: Ingo Molnar Cc: Thomas Gleixner Cc: Steven Rostedt Cc: Paul Gortmaker Cc: Tony Luck Cc: Fenghua Yu Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Martin Schwidefsky Cc: Heiko Carstens --- include/linux/kernel_stat.h | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'include/linux/kernel_stat.h') diff --git a/include/linux/kernel_stat.h b/include/linux/kernel_stat.h index 1865b1f29770..66b70780e910 100644 --- a/include/linux/kernel_stat.h +++ b/include/linux/kernel_stat.h @@ -127,7 +127,15 @@ extern void account_system_time(struct task_struct *, int, cputime_t, cputime_t) extern void account_steal_time(cputime_t); extern void account_idle_time(cputime_t); +#ifdef CONFIG_VIRT_CPU_ACCOUNTING +static inline void account_process_tick(struct task_struct *tsk, int user) +{ + vtime_account_user(tsk); +} +#else extern void account_process_tick(struct task_struct *, int user); +#endif + extern void account_steal_ticks(unsigned long ticks); extern void account_idle_ticks(unsigned long ticks); -- cgit v1.2.3 From abf917cd91cbb73952758f9741e2fa65002a48ee Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Wed, 25 Jul 2012 07:56:04 +0200 Subject: cputime: Generic on-demand virtual cputime accounting If we want to stop the tick further idle, we need to be able to account the cputime without using the tick. Virtual based cputime accounting solves that problem by hooking into kernel/user boundaries. However implementing CONFIG_VIRT_CPU_ACCOUNTING require low level hooks and involves more overhead. But we already have a generic context tracking subsystem that is required for RCU needs by archs which plan to shut down the tick outside idle. This patch implements a generic virtual based cputime accounting that relies on these generic kernel/user hooks. There are some upsides of doing this: - This requires no arch code to implement CONFIG_VIRT_CPU_ACCOUNTING if context tracking is already built (already necessary for RCU in full tickless mode). - We can rely on the generic context tracking subsystem to dynamically (de)activate the hooks, so that we can switch anytime between virtual and tick based accounting. This way we don't have the overhead of the virtual accounting when the tick is running periodically. And one downside: - There is probably more overhead than a native virtual based cputime accounting. But this relies on hooks that are already set anyway. Signed-off-by: Frederic Weisbecker Cc: Andrew Morton Cc: Ingo Molnar Cc: Li Zhong Cc: Namhyung Kim Cc: Paul E. McKenney Cc: Paul Gortmaker Cc: Peter Zijlstra Cc: Steven Rostedt Cc: Thomas Gleixner --- include/linux/kernel_stat.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux/kernel_stat.h') diff --git a/include/linux/kernel_stat.h b/include/linux/kernel_stat.h index 66b70780e910..ed5f6ed6eb77 100644 --- a/include/linux/kernel_stat.h +++ b/include/linux/kernel_stat.h @@ -127,7 +127,7 @@ extern void account_system_time(struct task_struct *, int, cputime_t, cputime_t) extern void account_steal_time(cputime_t); extern void account_idle_time(cputime_t); -#ifdef CONFIG_VIRT_CPU_ACCOUNTING +#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE static inline void account_process_tick(struct task_struct *tsk, int user) { vtime_account_user(tsk); -- cgit v1.2.3