From 57d2aa00dcec67afa52478730f2b524521af14fb Mon Sep 17 00:00:00 2001 From: Ying Xue Date: Tue, 17 Jul 2012 15:03:43 +0800 Subject: sched/rt: Avoid updating RT entry timeout twice within one tick period The issue below was found in 2.6.34-rt rather than mainline rt kernel, but the issue still exists upstream as well. So please let me describe how it was noticed on 2.6.34-rt: On this version, each softirq has its own thread, it means there is at least one RT FIFO task per cpu. The priority of these tasks is set to 49 by default. If user launches an RT FIFO task with priority lower than 49 of softirq RT tasks, it's possible there are two RT FIFO tasks enqueued one cpu runqueue at one moment. By current strategy of balancing RT tasks, when it comes to RT tasks, we really need to put them off to a CPU that they can run on as soon as possible. Even if it means a bit of cache line flushing, we want RT tasks to be run with the least latency. When the user RT FIFO task which just launched before is running, the sched timer tick of the current cpu happens. In this tick period, the timeout value of the user RT task will be updated once. Subsequently, we try to wake up one softirq RT task on its local cpu. As the priority of current user RT task is lower than the softirq RT task, the current task will be preempted by the higher priority softirq RT task. Before preemption, we check to see if current can readily move to a different cpu. If so, we will reschedule to allow the RT push logic to try to move current somewhere else. Whenever the woken softirq RT task runs, it first tries to migrate the user FIFO RT task over to a cpu that is running a task of lesser priority. If migration is done, it will send a reschedule request to the found cpu by IPI interrupt. Once the target cpu responds the IPI interrupt, it will pick the migrated user RT task to preempt its current task. When the user RT task is running on the new cpu, the sched timer tick of the cpu fires. So it will tick the user RT task again. This also means the RT task timeout value will be updated again. As the migration may be done in one tick period, it means the user RT task timeout value will be updated twice within one tick. If we set a limit on the amount of cpu time for the user RT task by setrlimit(RLIMIT_RTTIME), the SIGXCPU signal should be posted upon reaching the soft limit. But exactly when the SIGXCPU signal should be sent depends on the RT task timeout value. In fact the timeout mechanism of sending the SIGXCPU signal assumes the RT task timeout is increased once every tick. However, currently the timeout value may be added twice per tick. So it results in the SIGXCPU signal being sent earlier than expected. To solve this issue, we prevent the timeout value from increasing twice within one tick time by remembering the jiffies value of last updating the timeout. As long as the RT task's jiffies is different with the global jiffies value, we allow its timeout to be updated. Signed-off-by: Ying Xue Signed-off-by: Fan Du Reviewed-by: Yong Zhang Acked-by: Steven Rostedt Cc: Link: http://lkml.kernel.org/r/1342508623-2887-1-git-send-email-ying.xue@windriver.com Signed-off-by: Ingo Molnar --- include/linux/sched.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include') diff --git a/include/linux/sched.h b/include/linux/sched.h index d2112477ff5e..924e42a8df58 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1208,6 +1208,7 @@ struct sched_entity { struct sched_rt_entity { struct list_head run_list; unsigned long timeout; + unsigned long watchdog_stamp; unsigned int time_slice; struct sched_rt_entity *back; -- cgit v1.2.3 From 95a79fd458b85132c25e351d45037ec9643312b2 Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Mon, 7 Jan 2013 18:12:14 +0100 Subject: context_tracking: Export context state for generic vtime Export the context state: whether we run in user / kernel from the context tracking subsystem point of view. This is going to be used by the generic virtual cputime accounting subsystem that is needed to implement the full dynticks. 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/context_tracking.h | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) (limited to 'include') diff --git a/include/linux/context_tracking.h b/include/linux/context_tracking.h index e24339ccb7f0..b28d161c1091 100644 --- a/include/linux/context_tracking.h +++ b/include/linux/context_tracking.h @@ -3,12 +3,40 @@ #ifdef CONFIG_CONTEXT_TRACKING #include +#include + +struct context_tracking { + /* + * When active is false, probes are unset in order + * to minimize overhead: TIF flags are cleared + * and calls to user_enter/exit are ignored. This + * may be further optimized using static keys. + */ + bool active; + enum { + IN_KERNEL = 0, + IN_USER, + } state; +}; + +DECLARE_PER_CPU(struct context_tracking, context_tracking); + +static inline bool context_tracking_in_user(void) +{ + return __this_cpu_read(context_tracking.state) == IN_USER; +} + +static inline bool context_tracking_active(void) +{ + return __this_cpu_read(context_tracking.active); +} extern void user_enter(void); extern void user_exit(void); extern void context_tracking_task_switch(struct task_struct *prev, struct task_struct *next); #else +static inline bool context_tracking_in_user(void) { return false; } static inline void user_enter(void) { } static inline void user_exit(void) { } static inline void context_tracking_task_switch(struct task_struct *prev, -- cgit v1.2.3 From 39613766e8826756a4bf8c74274eb971c3c1d929 Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Tue, 15 Jan 2013 13:25:07 +0100 Subject: cputime: Librarize per nsecs resolution cputime definitions The full dynticks cputime accounting that we'll soon introduce will rely on sched_clock(). And its clock can have a per nanosecond granularity. To prepare for this, we need to have a cputime_t implementation that has this precision. ia64 virtual cputime accounting already uses that granularity so all we need is to librarize its implementation in the asm generic headers. Also librarize the default per jiffy granularity cputime_t as well so that we can easily pick either implementation depending on the cputime accounting config we choose. 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 Cc: Tony Luck Cc: Fenghua Yu --- include/asm-generic/cputime.h | 62 +--------------------- include/asm-generic/cputime_jiffies.h | 66 ++++++++++++++++++++++++ include/asm-generic/cputime_nsecs.h | 96 +++++++++++++++++++++++++++++++++++ 3 files changed, 163 insertions(+), 61 deletions(-) create mode 100644 include/asm-generic/cputime_jiffies.h create mode 100644 include/asm-generic/cputime_nsecs.h (limited to 'include') diff --git a/include/asm-generic/cputime.h b/include/asm-generic/cputime.h index 9a62937c56ca..c6eddf50eaf9 100644 --- a/include/asm-generic/cputime.h +++ b/include/asm-generic/cputime.h @@ -4,66 +4,6 @@ #include #include -typedef unsigned long __nocast cputime_t; - -#define cputime_one_jiffy jiffies_to_cputime(1) -#define cputime_to_jiffies(__ct) (__force unsigned long)(__ct) -#define cputime_to_scaled(__ct) (__ct) -#define jiffies_to_cputime(__hz) (__force cputime_t)(__hz) - -typedef u64 __nocast cputime64_t; - -#define cputime64_to_jiffies64(__ct) (__force u64)(__ct) -#define jiffies64_to_cputime64(__jif) (__force cputime64_t)(__jif) - -#define nsecs_to_cputime64(__ct) \ - jiffies64_to_cputime64(nsecs_to_jiffies64(__ct)) - - -/* - * Convert cputime to microseconds and back. - */ -#define cputime_to_usecs(__ct) \ - jiffies_to_usecs(cputime_to_jiffies(__ct)) -#define usecs_to_cputime(__usec) \ - jiffies_to_cputime(usecs_to_jiffies(__usec)) -#define usecs_to_cputime64(__usec) \ - jiffies64_to_cputime64(nsecs_to_jiffies64((__usec) * 1000)) - -/* - * Convert cputime to seconds and back. - */ -#define cputime_to_secs(jif) (cputime_to_jiffies(jif) / HZ) -#define secs_to_cputime(sec) jiffies_to_cputime((sec) * HZ) - -/* - * Convert cputime to timespec and back. - */ -#define timespec_to_cputime(__val) \ - jiffies_to_cputime(timespec_to_jiffies(__val)) -#define cputime_to_timespec(__ct,__val) \ - jiffies_to_timespec(cputime_to_jiffies(__ct),__val) - -/* - * Convert cputime to timeval and back. - */ -#define timeval_to_cputime(__val) \ - jiffies_to_cputime(timeval_to_jiffies(__val)) -#define cputime_to_timeval(__ct,__val) \ - jiffies_to_timeval(cputime_to_jiffies(__ct),__val) - -/* - * Convert cputime to clock and back. - */ -#define cputime_to_clock_t(__ct) \ - jiffies_to_clock_t(cputime_to_jiffies(__ct)) -#define clock_t_to_cputime(__x) \ - jiffies_to_cputime(clock_t_to_jiffies(__x)) - -/* - * Convert cputime64 to clock. - */ -#define cputime64_to_clock_t(__ct) \ - jiffies_64_to_clock_t(cputime64_to_jiffies64(__ct)) +#include #endif diff --git a/include/asm-generic/cputime_jiffies.h b/include/asm-generic/cputime_jiffies.h new file mode 100644 index 000000000000..b747f1fac2d2 --- /dev/null +++ b/include/asm-generic/cputime_jiffies.h @@ -0,0 +1,66 @@ +#ifndef _ASM_GENERIC_CPUTIME_JIFFIES_H +#define _ASM_GENERIC_CPUTIME_JIFFIES_H + +typedef unsigned long __nocast cputime_t; + +#define cputime_one_jiffy jiffies_to_cputime(1) +#define cputime_to_jiffies(__ct) (__force unsigned long)(__ct) +#define cputime_to_scaled(__ct) (__ct) +#define jiffies_to_cputime(__hz) (__force cputime_t)(__hz) + +typedef u64 __nocast cputime64_t; + +#define cputime64_to_jiffies64(__ct) (__force u64)(__ct) +#define jiffies64_to_cputime64(__jif) (__force cputime64_t)(__jif) + +#define nsecs_to_cputime64(__ct) \ + jiffies64_to_cputime64(nsecs_to_jiffies64(__ct)) + + +/* + * Convert cputime to microseconds and back. + */ +#define cputime_to_usecs(__ct) \ + jiffies_to_usecs(cputime_to_jiffies(__ct)) +#define usecs_to_cputime(__usec) \ + jiffies_to_cputime(usecs_to_jiffies(__usec)) +#define usecs_to_cputime64(__usec) \ + jiffies64_to_cputime64(nsecs_to_jiffies64((__usec) * 1000)) + +/* + * Convert cputime to seconds and back. + */ +#define cputime_to_secs(jif) (cputime_to_jiffies(jif) / HZ) +#define secs_to_cputime(sec) jiffies_to_cputime((sec) * HZ) + +/* + * Convert cputime to timespec and back. + */ +#define timespec_to_cputime(__val) \ + jiffies_to_cputime(timespec_to_jiffies(__val)) +#define cputime_to_timespec(__ct,__val) \ + jiffies_to_timespec(cputime_to_jiffies(__ct),__val) + +/* + * Convert cputime to timeval and back. + */ +#define timeval_to_cputime(__val) \ + jiffies_to_cputime(timeval_to_jiffies(__val)) +#define cputime_to_timeval(__ct,__val) \ + jiffies_to_timeval(cputime_to_jiffies(__ct),__val) + +/* + * Convert cputime to clock and back. + */ +#define cputime_to_clock_t(__ct) \ + jiffies_to_clock_t(cputime_to_jiffies(__ct)) +#define clock_t_to_cputime(__x) \ + jiffies_to_cputime(clock_t_to_jiffies(__x)) + +/* + * Convert cputime64 to clock. + */ +#define cputime64_to_clock_t(__ct) \ + jiffies_64_to_clock_t(cputime64_to_jiffies64(__ct)) + +#endif diff --git a/include/asm-generic/cputime_nsecs.h b/include/asm-generic/cputime_nsecs.h new file mode 100644 index 000000000000..c73d182f4751 --- /dev/null +++ b/include/asm-generic/cputime_nsecs.h @@ -0,0 +1,96 @@ +/* + * Definitions for measuring cputime in nsecs resolution. + * + * Based on + * + * Copyright (C) 2007 FUJITSU LIMITED + * Copyright (C) 2007 Hidetoshi Seto + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + * + */ + +#ifndef _ASM_GENERIC_CPUTIME_NSECS_H +#define _ASM_GENERIC_CPUTIME_NSECS_H + +typedef u64 __nocast cputime_t; +typedef u64 __nocast cputime64_t; + +#define cputime_one_jiffy jiffies_to_cputime(1) + +/* + * Convert cputime <-> jiffies (HZ) + */ +#define cputime_to_jiffies(__ct) \ + ((__force u64)(__ct) / (NSEC_PER_SEC / HZ)) +#define jiffies_to_cputime(__jif) \ + (__force cputime_t)((__jif) * (NSEC_PER_SEC / HZ)) +#define cputime64_to_jiffies64(__ct) \ + ((__force u64)(__ct) / (NSEC_PER_SEC / HZ)) +#define jiffies64_to_cputime64(__jif) \ + (__force cputime64_t)((__jif) * (NSEC_PER_SEC / HZ)) + +/* + * Convert cputime <-> microseconds + */ +#define cputime_to_usecs(__ct) \ + ((__force u64)(__ct) / NSEC_PER_USEC) +#define usecs_to_cputime(__usecs) \ + (__force cputime_t)((__usecs) * NSEC_PER_USEC) +#define usecs_to_cputime64(__usecs) \ + (__force cputime64_t)((__usecs) * NSEC_PER_USEC) + +/* + * Convert cputime <-> seconds + */ +#define cputime_to_secs(__ct) \ + ((__force u64)(__ct) / NSEC_PER_SEC) +#define secs_to_cputime(__secs) \ + (__force cputime_t)((__secs) * NSEC_PER_SEC) + +/* + * Convert cputime <-> timespec (nsec) + */ +static inline cputime_t timespec_to_cputime(const struct timespec *val) +{ + u64 ret = val->tv_sec * NSEC_PER_SEC + val->tv_nsec; + return (__force cputime_t) ret; +} +static inline void cputime_to_timespec(const cputime_t ct, struct timespec *val) +{ + val->tv_sec = (__force u64) ct / NSEC_PER_SEC; + val->tv_nsec = (__force u64) ct % NSEC_PER_SEC; +} + +/* + * Convert cputime <-> timeval (msec) + */ +static inline cputime_t timeval_to_cputime(struct timeval *val) +{ + u64 ret = val->tv_sec * NSEC_PER_SEC + val->tv_usec * NSEC_PER_USEC; + return (__force cputime_t) ret; +} +static inline void cputime_to_timeval(const cputime_t ct, struct timeval *val) +{ + val->tv_sec = (__force u64) ct / NSEC_PER_SEC; + val->tv_usec = ((__force u64) ct % NSEC_PER_SEC) / NSEC_PER_USEC; +} + +/* + * Convert cputime <-> clock (USER_HZ) + */ +#define cputime_to_clock_t(__ct) \ + ((__force u64)(__ct) / (NSEC_PER_SEC / USER_HZ)) +#define clock_t_to_cputime(__x) \ + (__force cputime_t)((__x) * (NSEC_PER_SEC / USER_HZ)) + +/* + * Convert cputime64 to clock. + */ +#define cputime64_to_clock_t(__ct) \ + cputime_to_clock_t((__force cputime_t)__ct) + +#endif -- cgit v1.2.3 From ae8dda5c473bf1a85913942adcaac449e5754bf3 Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Wed, 16 Jan 2013 18:02:04 +0100 Subject: cputime: Move default nsecs_to_cputime() to jiffies based cputime file If the architecture doesn't provide an implementation of nsecs_to_cputime(), the cputime accounting core uses a default one that converts the nanoseconds to jiffies. However this only makes sense if we use the jiffies based cputime. For now it doesn't matter much because this API is only called on code that uses jiffies based cputime accounting. But the code may evolve and this API may be used more broadly in the future. Keeping this default implementation around is very error prone as it may introduce a bug and hide it on architectures that don't override this API. Fix this by moving this definition to the jiffies based cputime headers as it is the only place where it belongs to. 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/asm-generic/cputime_jiffies.h | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) (limited to 'include') diff --git a/include/asm-generic/cputime_jiffies.h b/include/asm-generic/cputime_jiffies.h index b747f1fac2d2..272ecba9f588 100644 --- a/include/asm-generic/cputime_jiffies.h +++ b/include/asm-generic/cputime_jiffies.h @@ -13,8 +13,14 @@ typedef u64 __nocast cputime64_t; #define cputime64_to_jiffies64(__ct) (__force u64)(__ct) #define jiffies64_to_cputime64(__jif) (__force cputime64_t)(__jif) -#define nsecs_to_cputime64(__ct) \ - jiffies64_to_cputime64(nsecs_to_jiffies64(__ct)) + +/* + * Convert nanoseconds to cputime + */ +#define nsecs_to_cputime64(__nsec) \ + jiffies64_to_cputime64(nsecs_to_jiffies64(__nsec)) +#define nsecs_to_cputime(__nsec) \ + jiffies_to_cputime(nsecs_to_jiffies(__nsec)) /* -- 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/asm-generic/cputime.h | 8 +++++++- include/asm-generic/cputime_nsecs.h | 8 ++++++++ include/linux/kernel_stat.h | 2 +- include/linux/vtime.h | 16 ++++++++++++++++ 4 files changed, 32 insertions(+), 2 deletions(-) (limited to 'include') diff --git a/include/asm-generic/cputime.h b/include/asm-generic/cputime.h index c6eddf50eaf9..51969436b8b8 100644 --- a/include/asm-generic/cputime.h +++ b/include/asm-generic/cputime.h @@ -4,6 +4,12 @@ #include #include -#include +#ifndef CONFIG_VIRT_CPU_ACCOUNTING +# include +#endif + +#ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN +# include +#endif #endif diff --git a/include/asm-generic/cputime_nsecs.h b/include/asm-generic/cputime_nsecs.h index c73d182f4751..b6485cafb7bd 100644 --- a/include/asm-generic/cputime_nsecs.h +++ b/include/asm-generic/cputime_nsecs.h @@ -26,6 +26,7 @@ typedef u64 __nocast cputime64_t; */ #define cputime_to_jiffies(__ct) \ ((__force u64)(__ct) / (NSEC_PER_SEC / HZ)) +#define cputime_to_scaled(__ct) (__ct) #define jiffies_to_cputime(__jif) \ (__force cputime_t)((__jif) * (NSEC_PER_SEC / HZ)) #define cputime64_to_jiffies64(__ct) \ @@ -33,6 +34,13 @@ typedef u64 __nocast cputime64_t; #define jiffies64_to_cputime64(__jif) \ (__force cputime64_t)((__jif) * (NSEC_PER_SEC / HZ)) + +/* + * Convert cputime <-> nanoseconds + */ +#define nsecs_to_cputime(__nsecs) ((__force u64)(__nsecs)) + + /* * Convert cputime <-> microseconds */ 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); diff --git a/include/linux/vtime.h b/include/linux/vtime.h index ae30ab58431a..21ef703d1b25 100644 --- a/include/linux/vtime.h +++ b/include/linux/vtime.h @@ -14,9 +14,25 @@ extern void vtime_account(struct task_struct *tsk); 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_system_irqsafe(struct task_struct *tsk) { } +static inline void vtime_account_user(struct task_struct *tsk) { } static inline void vtime_account(struct task_struct *tsk) { } #endif +#ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN +static inline void arch_vtime_task_switch(struct task_struct *tsk) { } +static inline void vtime_user_enter(struct task_struct *tsk) +{ + vtime_account_system(tsk); +} +static inline void vtime_user_exit(struct task_struct *tsk) +{ + vtime_account_user(tsk); +} +#else +static inline void vtime_user_enter(struct task_struct *tsk) { } +static inline void vtime_user_exit(struct task_struct *tsk) { } +#endif + #ifdef CONFIG_IRQ_TIME_ACCOUNTING extern void irqtime_account_irq(struct task_struct *tsk); #else -- cgit v1.2.3 From 3f4724ea85b7d9055a9976fa8f30b471bdfbca93 Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Mon, 16 Jul 2012 18:00:34 +0200 Subject: cputime: Allow dynamic switch between tick/virtual based cputime accounting Allow to dynamically switch between tick and virtual based cputime accounting. This way we can provide a kind of "on-demand" virtual based cputime accounting. In this mode, the kernel relies on the context tracking subsystem to dynamically probe on kernel boundaries. This is in preparation for being able to stop the timer tick in more places than just the idle state. Doing so will depend on CONFIG_VIRT_CPU_ACCOUNTING_GEN which makes it possible to account the cputime without the tick by hooking on kernel/user boundaries. Depending whether the tick is stopped or not, we can switch between tick and vtime based accounting anytime in order to minimize the overhead associated to user hooks. 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/vtime.h | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'include') diff --git a/include/linux/vtime.h b/include/linux/vtime.h index 21ef703d1b25..5368af9bdf06 100644 --- a/include/linux/vtime.h +++ b/include/linux/vtime.h @@ -10,12 +10,20 @@ extern void vtime_account_system_irqsafe(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(struct task_struct *tsk); + +#ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN +extern bool vtime_accounting_enabled(void); #else +static inline bool vtime_accounting_enabled(void) { return true; } +#endif + +#else /* !CONFIG_VIRT_CPU_ACCOUNTING */ 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_system_irqsafe(struct task_struct *tsk) { } static inline void vtime_account_user(struct task_struct *tsk) { } static inline void vtime_account(struct task_struct *tsk) { } +static inline bool vtime_accounting_enabled(void) { return false; } #endif #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN -- cgit v1.2.3 From 6fac4829ce0ef9b7f24369086ce5f0e9f38d37bc Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Tue, 13 Nov 2012 14:20:55 +0100 Subject: cputime: Use accessors to read task cputime stats This is in preparation for the full dynticks feature. While remotely reading the cputime of a task running in a full dynticks CPU, we'll need to do some extra-computation. This way we can account the time it spent tickless in userspace since its last cputime snapshot. 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/sched.h | 23 +++++++++++++++++++++++ include/linux/tsacct_kern.h | 3 +++ 2 files changed, 26 insertions(+) (limited to 'include') diff --git a/include/linux/sched.h b/include/linux/sched.h index 6fc8f45de4e9..a9c608b6154e 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1792,6 +1792,29 @@ static inline void put_task_struct(struct task_struct *t) __put_task_struct(t); } +static inline cputime_t task_gtime(struct task_struct *t) +{ + return t->gtime; +} + +static inline void task_cputime(struct task_struct *t, + cputime_t *utime, cputime_t *stime) +{ + if (utime) + *utime = t->utime; + if (stime) + *stime = t->stime; +} + +static inline void task_cputime_scaled(struct task_struct *t, + cputime_t *utimescaled, + cputime_t *stimescaled) +{ + if (utimescaled) + *utimescaled = t->utimescaled; + if (stimescaled) + *stimescaled = t->stimescaled; +} extern void task_cputime_adjusted(struct task_struct *p, cputime_t *ut, cputime_t *st); extern void thread_group_cputime_adjusted(struct task_struct *p, cputime_t *ut, cputime_t *st); diff --git a/include/linux/tsacct_kern.h b/include/linux/tsacct_kern.h index 44893e5ec8f7..3251965bf4cc 100644 --- a/include/linux/tsacct_kern.h +++ b/include/linux/tsacct_kern.h @@ -23,12 +23,15 @@ static inline void bacct_add_tsk(struct user_namespace *user_ns, #ifdef CONFIG_TASK_XACCT extern void xacct_add_tsk(struct taskstats *stats, struct task_struct *p); extern void acct_update_integrals(struct task_struct *tsk); +extern void acct_account_cputime(struct task_struct *tsk); extern void acct_clear_integrals(struct task_struct *tsk); #else static inline void xacct_add_tsk(struct taskstats *stats, struct task_struct *p) {} static inline void acct_update_integrals(struct task_struct *tsk) {} +static inline void acct_account_cputime(struct task_struct *tsk) +{} static inline void acct_clear_integrals(struct task_struct *tsk) {} #endif /* CONFIG_TASK_XACCT */ -- cgit v1.2.3 From c11f11fcbdb5be790c565aed46411486a7586afc Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Mon, 21 Jan 2013 00:50:22 +0100 Subject: kvm: Prepare to add generic guest entry/exit callbacks Do some ground preparatory work before adding guest_enter() and guest_exit() context tracking callbacks. Those will be later used to read the guest cputime safely when we run in full dynticks mode. Signed-off-by: Frederic Weisbecker Cc: Andrew Morton Cc: Gleb Natapov Cc: Ingo Molnar Cc: Li Zhong Cc: Marcelo Tosatti Cc: Namhyung Kim Cc: Paul E. McKenney Cc: Paul Gortmaker Cc: Peter Zijlstra Cc: Steven Rostedt Cc: Thomas Gleixner --- include/linux/kvm_host.h | 39 ++++++++++++++++++++++++++++++--------- include/linux/vtime.h | 2 -- 2 files changed, 30 insertions(+), 11 deletions(-) (limited to 'include') diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 2c497ab0d03d..4fe2396401da 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -22,6 +22,7 @@ #include #include #include +#include #include #include @@ -740,15 +741,36 @@ static inline int kvm_deassign_device(struct kvm *kvm, } #endif /* CONFIG_IOMMU_API */ -static inline void kvm_guest_enter(void) +static inline void guest_enter(void) { - BUG_ON(preemptible()); /* * This is running in ioctl context so we can avoid * the call to vtime_account() with its unnecessary idle check. */ - vtime_account_system_irqsafe(current); + vtime_account_system(current); current->flags |= PF_VCPU; +} + +static inline void guest_exit(void) +{ + /* + * This is running in ioctl context so we can avoid + * the call to vtime_account() with its unnecessary idle check. + */ + vtime_account_system(current); + current->flags &= ~PF_VCPU; +} + +static inline void kvm_guest_enter(void) +{ + unsigned long flags; + + BUG_ON(preemptible()); + + local_irq_save(flags); + guest_enter(); + local_irq_restore(flags); + /* 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 * is very similar to exiting to userspase from rcu point of view. In @@ -761,12 +783,11 @@ static inline void kvm_guest_enter(void) static inline void kvm_guest_exit(void) { - /* - * This is running in ioctl context so we can avoid - * the call to vtime_account() with its unnecessary idle check. - */ - vtime_account_system_irqsafe(current); - current->flags &= ~PF_VCPU; + unsigned long flags; + + local_irq_save(flags); + guest_exit(); + local_irq_restore(flags); } /* diff --git a/include/linux/vtime.h b/include/linux/vtime.h index 5368af9bdf06..bb50c3ca0d79 100644 --- a/include/linux/vtime.h +++ b/include/linux/vtime.h @@ -6,7 +6,6 @@ struct task_struct; #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_system_irqsafe(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(struct task_struct *tsk); @@ -20,7 +19,6 @@ static inline bool vtime_accounting_enabled(void) { return true; } #else /* !CONFIG_VIRT_CPU_ACCOUNTING */ 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_system_irqsafe(struct task_struct *tsk) { } static inline void vtime_account_user(struct task_struct *tsk) { } static inline void vtime_account(struct task_struct *tsk) { } static inline bool vtime_accounting_enabled(void) { return false; } -- cgit v1.2.3 From 6a61671bb2f3a1bd12cd17b8fca811a624782632 Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Sun, 16 Dec 2012 20:00:34 +0100 Subject: cputime: Safely read cputime of full dynticks CPUs While remotely reading the cputime of a task running in a full dynticks CPU, the values stored in utime/stime fields of struct task_struct may be stale. Its values may be those of the last kernel <-> user transition time snapshot and we need to add the tickless time spent since this snapshot. To fix this, flush the cputime of the dynticks CPUs on kernel <-> user transition and record the time / context where we did this. Then on top of this snapshot and the current time, perform the fixup on the reader side from task_times() accessors. 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 [fixed kvm module related build errors] Signed-off-by: Sedat Dilek --- include/linux/hardirq.h | 4 ++-- include/linux/init_task.h | 11 +++++++++++ include/linux/kvm_host.h | 20 ++++++++++++++++++-- include/linux/sched.h | 27 ++++++++++++++++++++++----- include/linux/vtime.h | 47 +++++++++++++++++++++++------------------------ 5 files changed, 76 insertions(+), 33 deletions(-) (limited to 'include') diff --git a/include/linux/hardirq.h b/include/linux/hardirq.h index 624ef3f45c8e..7105d5cbb762 100644 --- a/include/linux/hardirq.h +++ b/include/linux/hardirq.h @@ -153,7 +153,7 @@ extern void rcu_nmi_exit(void); */ #define __irq_enter() \ do { \ - vtime_account_irq_enter(current); \ + account_irq_enter_time(current); \ add_preempt_count(HARDIRQ_OFFSET); \ trace_hardirq_enter(); \ } while (0) @@ -169,7 +169,7 @@ extern void irq_enter(void); #define __irq_exit() \ do { \ trace_hardirq_exit(); \ - vtime_account_irq_exit(current); \ + account_irq_exit_time(current); \ sub_preempt_count(HARDIRQ_OFFSET); \ } while (0) diff --git a/include/linux/init_task.h b/include/linux/init_task.h index 6d087c5f57f7..cc898b871cef 100644 --- a/include/linux/init_task.h +++ b/include/linux/init_task.h @@ -10,6 +10,7 @@ #include #include #include +#include #include #ifdef CONFIG_SMP @@ -141,6 +142,15 @@ extern struct task_group root_task_group; # define INIT_PERF_EVENTS(tsk) #endif +#ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN +# define INIT_VTIME(tsk) \ + .vtime_seqlock = __SEQLOCK_UNLOCKED(tsk.vtime_seqlock), \ + .vtime_snap = 0, \ + .vtime_snap_whence = VTIME_SYS, +#else +# define INIT_VTIME(tsk) +#endif + #define INIT_TASK_COMM "swapper" /* @@ -210,6 +220,7 @@ extern struct task_group root_task_group; INIT_TRACE_RECURSION \ INIT_TASK_RCU_PREEMPT(tsk) \ INIT_CPUSET_SEQ \ + INIT_VTIME(tsk) \ } diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 4fe2396401da..b7996a768eb2 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -741,7 +741,7 @@ static inline int kvm_deassign_device(struct kvm *kvm, } #endif /* CONFIG_IOMMU_API */ -static inline void guest_enter(void) +static inline void __guest_enter(void) { /* * This is running in ioctl context so we can avoid @@ -751,7 +751,7 @@ static inline void guest_enter(void) current->flags |= PF_VCPU; } -static inline void guest_exit(void) +static inline void __guest_exit(void) { /* * This is running in ioctl context so we can avoid @@ -761,6 +761,22 @@ static inline void guest_exit(void) current->flags &= ~PF_VCPU; } +#ifdef CONFIG_CONTEXT_TRACKING +extern void guest_enter(void); +extern void guest_exit(void); + +#else /* !CONFIG_CONTEXT_TRACKING */ +static inline void guest_enter(void) +{ + __guest_enter(); +} + +static inline void guest_exit(void) +{ + __guest_exit(); +} +#endif /* !CONFIG_CONTEXT_TRACKING */ + static inline void kvm_guest_enter(void) { unsigned long flags; diff --git a/include/linux/sched.h b/include/linux/sched.h index a9c608b6154e..a9fa5145e1a7 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1367,6 +1367,15 @@ struct task_struct { cputime_t gtime; #ifndef CONFIG_VIRT_CPU_ACCOUNTING struct cputime prev_cputime; +#endif +#ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN + seqlock_t vtime_seqlock; + unsigned long long vtime_snap; + enum { + VTIME_SLEEPING = 0, + VTIME_USER, + VTIME_SYS, + } vtime_snap_whence; #endif unsigned long nvcsw, nivcsw; /* context switch counts */ struct timespec start_time; /* monotonic time */ @@ -1792,11 +1801,13 @@ static inline void put_task_struct(struct task_struct *t) __put_task_struct(t); } -static inline cputime_t task_gtime(struct task_struct *t) -{ - return t->gtime; -} - +#ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN +extern void task_cputime(struct task_struct *t, + cputime_t *utime, cputime_t *stime); +extern void task_cputime_scaled(struct task_struct *t, + cputime_t *utimescaled, cputime_t *stimescaled); +extern cputime_t task_gtime(struct task_struct *t); +#else static inline void task_cputime(struct task_struct *t, cputime_t *utime, cputime_t *stime) { @@ -1815,6 +1826,12 @@ static inline void task_cputime_scaled(struct task_struct *t, if (stimescaled) *stimescaled = t->stimescaled; } + +static inline cputime_t task_gtime(struct task_struct *t) +{ + return t->gtime; +} +#endif extern void task_cputime_adjusted(struct task_struct *p, cputime_t *ut, cputime_t *st); extern void thread_group_cputime_adjusted(struct task_struct *p, cputime_t *ut, cputime_t *st); diff --git a/include/linux/vtime.h b/include/linux/vtime.h index bb50c3ca0d79..71a5782d8c59 100644 --- a/include/linux/vtime.h +++ b/include/linux/vtime.h @@ -8,35 +8,44 @@ 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); extern void vtime_account_user(struct task_struct *tsk); -extern void vtime_account(struct task_struct *tsk); +extern void vtime_account_irq_enter(struct task_struct *tsk); -#ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN -extern bool vtime_accounting_enabled(void); -#else +#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE static inline bool vtime_accounting_enabled(void) { return true; } #endif #else /* !CONFIG_VIRT_CPU_ACCOUNTING */ + 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(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 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN -static inline void arch_vtime_task_switch(struct task_struct *tsk) { } -static inline void vtime_user_enter(struct task_struct *tsk) -{ - vtime_account_system(tsk); -} +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_user_enter(struct task_struct *tsk); static inline void vtime_user_exit(struct task_struct *tsk) { vtime_account_user(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); #else +static inline void vtime_account_irq_exit(struct task_struct *tsk) +{ + /* On hard|softirq exit we always account to hard|softirq cputime */ + vtime_account_system(tsk); +} static inline void vtime_user_enter(struct task_struct *tsk) { } static inline void vtime_user_exit(struct task_struct *tsk) { } +static inline void vtime_guest_enter(struct task_struct *tsk) { } +static inline void vtime_guest_exit(struct task_struct *tsk) { } +static inline void vtime_init_idle(struct task_struct *tsk) { } #endif #ifdef CONFIG_IRQ_TIME_ACCOUNTING @@ -45,25 +54,15 @@ extern void irqtime_account_irq(struct task_struct *tsk); static inline void irqtime_account_irq(struct task_struct *tsk) { } #endif -static inline void vtime_account_irq_enter(struct task_struct *tsk) +static inline void account_irq_enter_time(struct task_struct *tsk) { - /* - * Hardirq can interrupt idle task anytime. So we need vtime_account() - * that performs the idle check in CONFIG_VIRT_CPU_ACCOUNTING. - * Softirq can also interrupt idle task directly if it calls - * local_bh_enable(). Such case probably don't exist but we never know. - * Ksoftirqd is not concerned because idle time is flushed on context - * switch. Softirqs in the end of hardirqs are also not a problem because - * the idle time is flushed on hardirq time already. - */ - vtime_account(tsk); + vtime_account_irq_enter(tsk); irqtime_account_irq(tsk); } -static inline void vtime_account_irq_exit(struct task_struct *tsk) +static inline void account_irq_exit_time(struct task_struct *tsk) { - /* On hard|softirq exit we always account to hard|softirq cputime */ - vtime_account_system(tsk); + vtime_account_irq_exit(tsk); irqtime_account_irq(tsk); } -- cgit v1.2.3 From cf4aebc292fac7f34f8345664320e9d4a42ca76c Mon Sep 17 00:00:00 2001 From: Clark Williams Date: Thu, 7 Feb 2013 09:46:59 -0600 Subject: sched: Move sched.h sysctl bits into separate header Move the sysctl-related bits from include/linux/sched.h into a new file: include/linux/sched/sysctl.h. Then update source files requiring access to those bits by including the new header file. Signed-off-by: Clark Williams Cc: Peter Zijlstra Cc: Steven Rostedt Link: http://lkml.kernel.org/r/20130207094659.06dced96@riff.lan Signed-off-by: Ingo Molnar --- include/linux/sched.h | 91 ----------------------------------------- include/linux/sched/sysctl.h | 97 ++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 97 insertions(+), 91 deletions(-) create mode 100644 include/linux/sched/sysctl.h (limited to 'include') diff --git a/include/linux/sched.h b/include/linux/sched.h index 719ee0815e3a..8fc9b2710a80 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -304,19 +304,6 @@ static inline void lockup_detector_init(void) } #endif -#ifdef CONFIG_DETECT_HUNG_TASK -extern unsigned int sysctl_hung_task_panic; -extern unsigned long sysctl_hung_task_check_count; -extern unsigned long sysctl_hung_task_timeout_secs; -extern unsigned long sysctl_hung_task_warnings; -extern int proc_dohung_task_timeout_secs(struct ctl_table *table, int write, - void __user *buffer, - size_t *lenp, loff_t *ppos); -#else -/* Avoid need for ifdefs elsewhere in the code */ -enum { sysctl_hung_task_timeout_secs = 0 }; -#endif - /* Attach to any functions which should be ignored in wchan output. */ #define __sched __attribute__((__section__(".sched.text"))) @@ -338,23 +325,6 @@ extern int mutex_spin_on_owner(struct mutex *lock, struct task_struct *owner); struct nsproxy; struct user_namespace; -/* - * Default maximum number of active map areas, this limits the number of vmas - * per mm struct. Users can overwrite this number by sysctl but there is a - * problem. - * - * When a program's coredump is generated as ELF format, a section is created - * per a vma. In ELF, the number of sections is represented in unsigned short. - * This means the number of sections should be smaller than 65535 at coredump. - * Because the kernel adds some informative sections to a image of program at - * generating coredump, we need some margin. The number of extra sections is - * 1-3 now and depends on arch. We use "5" as safe margin, here. - */ -#define MAPCOUNT_ELF_CORE_MARGIN (5) -#define DEFAULT_MAX_MAP_COUNT (USHRT_MAX - MAPCOUNT_ELF_CORE_MARGIN) - -extern int sysctl_max_map_count; - #include #ifdef CONFIG_MMU @@ -1221,12 +1191,6 @@ struct sched_rt_entity { #endif }; -/* - * default timeslice is 100 msecs (used only for SCHED_RR tasks). - * Timeslices get refilled after they expire. - */ -#define RR_TIMESLICE (100 * HZ / 1000) - struct rcu_node; enum perf_event_task_context { @@ -2074,58 +2038,7 @@ extern void wake_up_idle_cpu(int cpu); static inline void wake_up_idle_cpu(int cpu) { } #endif -extern unsigned int sysctl_sched_latency; -extern unsigned int sysctl_sched_min_granularity; -extern unsigned int sysctl_sched_wakeup_granularity; -extern unsigned int sysctl_sched_child_runs_first; - -enum sched_tunable_scaling { - SCHED_TUNABLESCALING_NONE, - SCHED_TUNABLESCALING_LOG, - SCHED_TUNABLESCALING_LINEAR, - SCHED_TUNABLESCALING_END, -}; -extern enum sched_tunable_scaling sysctl_sched_tunable_scaling; - -extern unsigned int sysctl_numa_balancing_scan_delay; -extern unsigned int sysctl_numa_balancing_scan_period_min; -extern unsigned int sysctl_numa_balancing_scan_period_max; -extern unsigned int sysctl_numa_balancing_scan_period_reset; -extern unsigned int sysctl_numa_balancing_scan_size; -extern unsigned int sysctl_numa_balancing_settle_count; - -#ifdef CONFIG_SCHED_DEBUG -extern unsigned int sysctl_sched_migration_cost; -extern unsigned int sysctl_sched_nr_migrate; -extern unsigned int sysctl_sched_time_avg; -extern unsigned int sysctl_timer_migration; -extern unsigned int sysctl_sched_shares_window; - -int sched_proc_update_handler(struct ctl_table *table, int write, - void __user *buffer, size_t *length, - loff_t *ppos); -#endif -#ifdef CONFIG_SCHED_DEBUG -static inline unsigned int get_sysctl_timer_migration(void) -{ - return sysctl_timer_migration; -} -#else -static inline unsigned int get_sysctl_timer_migration(void) -{ - return 1; -} -#endif -extern unsigned int sysctl_sched_rt_period; -extern int sysctl_sched_rt_runtime; - -int sched_rt_handler(struct ctl_table *table, int write, - void __user *buffer, size_t *lenp, - loff_t *ppos); - #ifdef CONFIG_SCHED_AUTOGROUP -extern unsigned int sysctl_sched_autogroup_enabled; - extern void sched_autogroup_create_attach(struct task_struct *p); extern void sched_autogroup_detach(struct task_struct *p); extern void sched_autogroup_fork(struct signal_struct *sig); @@ -2141,10 +2054,6 @@ static inline void sched_autogroup_fork(struct signal_struct *sig) { } static inline void sched_autogroup_exit(struct signal_struct *sig) { } #endif -#ifdef CONFIG_CFS_BANDWIDTH -extern unsigned int sysctl_sched_cfs_bandwidth_slice; -#endif - #ifdef CONFIG_RT_MUTEXES extern int rt_mutex_getprio(struct task_struct *p); extern void rt_mutex_setprio(struct task_struct *p, int prio); diff --git a/include/linux/sched/sysctl.h b/include/linux/sched/sysctl.h new file mode 100644 index 000000000000..bac914e458ca --- /dev/null +++ b/include/linux/sched/sysctl.h @@ -0,0 +1,97 @@ +#ifndef _SCHED_SYSCTL_H +#define _SCHED_SYSCTL_H + +#ifdef CONFIG_DETECT_HUNG_TASK +extern unsigned int sysctl_hung_task_panic; +extern unsigned long sysctl_hung_task_check_count; +extern unsigned long sysctl_hung_task_timeout_secs; +extern unsigned long sysctl_hung_task_warnings; +extern int proc_dohung_task_timeout_secs(struct ctl_table *table, int write, + void __user *buffer, + size_t *lenp, loff_t *ppos); +#else +/* Avoid need for ifdefs elsewhere in the code */ +enum { sysctl_hung_task_timeout_secs = 0 }; +#endif + +/* + * Default maximum number of active map areas, this limits the number of vmas + * per mm struct. Users can overwrite this number by sysctl but there is a + * problem. + * + * When a program's coredump is generated as ELF format, a section is created + * per a vma. In ELF, the number of sections is represented in unsigned short. + * This means the number of sections should be smaller than 65535 at coredump. + * Because the kernel adds some informative sections to a image of program at + * generating coredump, we need some margin. The number of extra sections is + * 1-3 now and depends on arch. We use "5" as safe margin, here. + */ +#define MAPCOUNT_ELF_CORE_MARGIN (5) +#define DEFAULT_MAX_MAP_COUNT (USHRT_MAX - MAPCOUNT_ELF_CORE_MARGIN) + +extern int sysctl_max_map_count; + +extern unsigned int sysctl_sched_latency; +extern unsigned int sysctl_sched_min_granularity; +extern unsigned int sysctl_sched_wakeup_granularity; +extern unsigned int sysctl_sched_child_runs_first; + +enum sched_tunable_scaling { + SCHED_TUNABLESCALING_NONE, + SCHED_TUNABLESCALING_LOG, + SCHED_TUNABLESCALING_LINEAR, + SCHED_TUNABLESCALING_END, +}; +extern enum sched_tunable_scaling sysctl_sched_tunable_scaling; + +extern unsigned int sysctl_numa_balancing_scan_delay; +extern unsigned int sysctl_numa_balancing_scan_period_min; +extern unsigned int sysctl_numa_balancing_scan_period_max; +extern unsigned int sysctl_numa_balancing_scan_period_reset; +extern unsigned int sysctl_numa_balancing_scan_size; +extern unsigned int sysctl_numa_balancing_settle_count; + +#ifdef CONFIG_SCHED_DEBUG +extern unsigned int sysctl_sched_migration_cost; +extern unsigned int sysctl_sched_nr_migrate; +extern unsigned int sysctl_sched_time_avg; +extern unsigned int sysctl_timer_migration; +extern unsigned int sysctl_sched_shares_window; + +int sched_proc_update_handler(struct ctl_table *table, int write, + void __user *buffer, size_t *length, + loff_t *ppos); +#endif +#ifdef CONFIG_SCHED_DEBUG +static inline unsigned int get_sysctl_timer_migration(void) +{ + return sysctl_timer_migration; +} +#else +static inline unsigned int get_sysctl_timer_migration(void) +{ + return 1; +} +#endif +extern unsigned int sysctl_sched_rt_period; +extern int sysctl_sched_rt_runtime; + +#ifdef CONFIG_CFS_BANDWIDTH +extern unsigned int sysctl_sched_cfs_bandwidth_slice; +#endif + +#ifdef CONFIG_SCHED_AUTOGROUP +extern unsigned int sysctl_sched_autogroup_enabled; +#endif + +/* + * default timeslice is 100 msecs (used only for SCHED_RR tasks). + * Timeslices get refilled after they expire. + */ +#define RR_TIMESLICE (100 * HZ / 1000) + +int sched_rt_handler(struct ctl_table *table, int write, + void __user *buffer, size_t *lenp, + loff_t *ppos); + +#endif /* _SCHED_SYSCTL_H */ -- cgit v1.2.3 From ce0dbbbb30aee6a835511d5be446462388ba9eee Mon Sep 17 00:00:00 2001 From: Clark Williams Date: Thu, 7 Feb 2013 09:47:04 -0600 Subject: sched/rt: Add a tuning knob to allow changing SCHED_RR timeslice Add a /proc/sys/kernel scheduler knob named sched_rr_timeslice_ms that allows global changing of the SCHED_RR timeslice value. User visable value is in milliseconds but is stored as jiffies. Setting to 0 (zero) resets to the default (currently 100ms). Signed-off-by: Clark Williams Cc: Peter Zijlstra Cc: Steven Rostedt Link: http://lkml.kernel.org/r/20130207094704.13751796@riff.lan Signed-off-by: Ingo Molnar --- include/linux/sched/sysctl.h | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-) (limited to 'include') diff --git a/include/linux/sched/sysctl.h b/include/linux/sched/sysctl.h index bac914e458ca..d2bb0ae979d0 100644 --- a/include/linux/sched/sysctl.h +++ b/include/linux/sched/sysctl.h @@ -73,6 +73,13 @@ static inline unsigned int get_sysctl_timer_migration(void) return 1; } #endif + +/* + * control realtime throttling: + * + * /proc/sys/kernel/sched_rt_period_us + * /proc/sys/kernel/sched_rt_runtime_us + */ extern unsigned int sysctl_sched_rt_period; extern int sysctl_sched_rt_runtime; @@ -90,7 +97,13 @@ extern unsigned int sysctl_sched_autogroup_enabled; */ #define RR_TIMESLICE (100 * HZ / 1000) -int sched_rt_handler(struct ctl_table *table, int write, +extern int sched_rr_timeslice; + +extern int sched_rr_handler(struct ctl_table *table, int write, + void __user *buffer, size_t *lenp, + loff_t *ppos); + +extern int sched_rt_handler(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos); -- cgit v1.2.3 From 8bd75c77b7c6a3954140dd2e20346aef3efe4a35 Mon Sep 17 00:00:00 2001 From: Clark Williams Date: Thu, 7 Feb 2013 09:47:07 -0600 Subject: sched/rt: Move rt specific bits into new header file Move rt scheduler definitions out of include/linux/sched.h into new file include/linux/sched/rt.h Signed-off-by: Clark Williams Cc: Peter Zijlstra Cc: Steven Rostedt Link: http://lkml.kernel.org/r/20130207094707.7b9f825f@riff.lan Signed-off-by: Ingo Molnar --- include/linux/sched.h | 55 ++------------------------------------------- include/linux/sched/rt.h | 58 ++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 60 insertions(+), 53 deletions(-) create mode 100644 include/linux/sched/rt.h (limited to 'include') diff --git a/include/linux/sched.h b/include/linux/sched.h index 8fc9b2710a80..33cc42130371 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1164,6 +1164,7 @@ struct sched_entity { /* rq "owned" by this entity/group: */ struct cfs_rq *my_q; #endif + /* * Load-tracking only depends on SMP, FAIR_GROUP_SCHED dependency below may be * removed when useful for applications beyond shares distribution (e.g. @@ -1191,6 +1192,7 @@ struct sched_rt_entity { #endif }; + struct rcu_node; enum perf_event_task_context { @@ -1596,37 +1598,6 @@ static inline void set_numabalancing_state(bool enabled) } #endif -/* - * Priority of a process goes from 0..MAX_PRIO-1, valid RT - * priority is 0..MAX_RT_PRIO-1, and SCHED_NORMAL/SCHED_BATCH - * tasks are in the range MAX_RT_PRIO..MAX_PRIO-1. Priority - * values are inverted: lower p->prio value means higher priority. - * - * The MAX_USER_RT_PRIO value allows the actual maximum - * RT priority to be separate from the value exported to - * user-space. This allows kernel threads to set their - * priority to a value higher than any user task. Note: - * MAX_RT_PRIO must not be smaller than MAX_USER_RT_PRIO. - */ - -#define MAX_USER_RT_PRIO 100 -#define MAX_RT_PRIO MAX_USER_RT_PRIO - -#define MAX_PRIO (MAX_RT_PRIO + 40) -#define DEFAULT_PRIO (MAX_RT_PRIO + 20) - -static inline int rt_prio(int prio) -{ - if (unlikely(prio < MAX_RT_PRIO)) - return 1; - return 0; -} - -static inline int rt_task(struct task_struct *p) -{ - return rt_prio(p->prio); -} - static inline struct pid *task_pid(struct task_struct *task) { return task->pids[PIDTYPE_PID].pid; @@ -2054,26 +2025,6 @@ static inline void sched_autogroup_fork(struct signal_struct *sig) { } static inline void sched_autogroup_exit(struct signal_struct *sig) { } #endif -#ifdef CONFIG_RT_MUTEXES -extern int rt_mutex_getprio(struct task_struct *p); -extern void rt_mutex_setprio(struct task_struct *p, int prio); -extern void rt_mutex_adjust_pi(struct task_struct *p); -static inline bool tsk_is_pi_blocked(struct task_struct *tsk) -{ - return tsk->pi_blocked_on != NULL; -} -#else -static inline int rt_mutex_getprio(struct task_struct *p) -{ - return p->normal_prio; -} -# define rt_mutex_adjust_pi(p) do { } while (0) -static inline bool tsk_is_pi_blocked(struct task_struct *tsk) -{ - return false; -} -#endif - extern bool yield_to(struct task_struct *p, bool preempt); extern void set_user_nice(struct task_struct *p, long nice); extern int task_prio(const struct task_struct *p); @@ -2703,8 +2654,6 @@ static inline void set_task_cpu(struct task_struct *p, unsigned int cpu) extern long sched_setaffinity(pid_t pid, const struct cpumask *new_mask); extern long sched_getaffinity(pid_t pid, struct cpumask *mask); -extern void normalize_rt_tasks(void); - #ifdef CONFIG_CGROUP_SCHED extern struct task_group root_task_group; diff --git a/include/linux/sched/rt.h b/include/linux/sched/rt.h new file mode 100644 index 000000000000..94e19ea28fc3 --- /dev/null +++ b/include/linux/sched/rt.h @@ -0,0 +1,58 @@ +#ifndef _SCHED_RT_H +#define _SCHED_RT_H + +/* + * Priority of a process goes from 0..MAX_PRIO-1, valid RT + * priority is 0..MAX_RT_PRIO-1, and SCHED_NORMAL/SCHED_BATCH + * tasks are in the range MAX_RT_PRIO..MAX_PRIO-1. Priority + * values are inverted: lower p->prio value means higher priority. + * + * The MAX_USER_RT_PRIO value allows the actual maximum + * RT priority to be separate from the value exported to + * user-space. This allows kernel threads to set their + * priority to a value higher than any user task. Note: + * MAX_RT_PRIO must not be smaller than MAX_USER_RT_PRIO. + */ + +#define MAX_USER_RT_PRIO 100 +#define MAX_RT_PRIO MAX_USER_RT_PRIO + +#define MAX_PRIO (MAX_RT_PRIO + 40) +#define DEFAULT_PRIO (MAX_RT_PRIO + 20) + +static inline int rt_prio(int prio) +{ + if (unlikely(prio < MAX_RT_PRIO)) + return 1; + return 0; +} + +static inline int rt_task(struct task_struct *p) +{ + return rt_prio(p->prio); +} + +#ifdef CONFIG_RT_MUTEXES +extern int rt_mutex_getprio(struct task_struct *p); +extern void rt_mutex_setprio(struct task_struct *p, int prio); +extern void rt_mutex_adjust_pi(struct task_struct *p); +static inline bool tsk_is_pi_blocked(struct task_struct *tsk) +{ + return tsk->pi_blocked_on != NULL; +} +#else +static inline int rt_mutex_getprio(struct task_struct *p) +{ + return p->normal_prio; +} +# define rt_mutex_adjust_pi(p) do { } while (0) +static inline bool tsk_is_pi_blocked(struct task_struct *tsk) +{ + return false; +} +#endif + +extern void normalize_rt_tasks(void); + + +#endif /* _SCHED_RT_H */ -- cgit v1.2.3 From 77852fea6e2442a0e654a9292060489895de18c7 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Sat, 16 Feb 2013 09:46:48 +0100 Subject: sched/rt: Add header to IA64 relied on it through sched.h inclusion: arch/ia64/kernel/init_task.c:38:11: error: 'MAX_PRIO' undeclared here (not in a function) arch/ia64/kernel/init_task.c:38:11: error: 'RR_TIMESLICE' undeclared here (not in a function) Reported-by: kbuild test robot Cc: Clark Williams Cc: Peter Zijlstra Cc: Steven Rostedt Link: http://lkml.kernel.org/n/tip-xaan1twswggedMR0airtpjui@git.kernel.org Signed-off-by: Ingo Molnar --- include/linux/init_task.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include') diff --git a/include/linux/init_task.h b/include/linux/init_task.h index cc898b871cef..5cd0f0949927 100644 --- a/include/linux/init_task.h +++ b/include/linux/init_task.h @@ -12,6 +12,7 @@ #include #include #include +#include #ifdef CONFIG_SMP # define INIT_PUSHABLE_TASKS(tsk) \ -- cgit v1.2.3