From 07dd20e0324f4d3e33bde1944d4f7771a09c498c Mon Sep 17 00:00:00 2001 From: Richard Kennedy Date: Fri, 1 Aug 2008 13:18:04 +0100 Subject: sched: reorder signal_struct to remove 8 bytes on 64 bit builds reorder structure to remove 8 bytes of padding on 64 bit builds Signed-off-by: Richard Kennedy Signed-off-by: Ingo Molnar --- include/linux/sched.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include') diff --git a/include/linux/sched.h b/include/linux/sched.h index cfb0d87b99fc..5a8058e44f58 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -451,8 +451,8 @@ struct signal_struct { * - everyone except group_exit_task is stopped during signal delivery * of fatal signals, group_exit_task processes the signal. */ - struct task_struct *group_exit_task; int notify_count; + struct task_struct *group_exit_task; /* thread group stop support, overloads group_exit_code too */ int group_stop_count; -- cgit v1.2.3 From bee367ed066e26c14263d808136fba8eec3bd70a Mon Sep 17 00:00:00 2001 From: Richard Kennedy Date: Fri, 1 Aug 2008 13:24:08 +0100 Subject: sched: reorder struct sched_rt_entity to remove padding on 64 bit builds remove 8 bytes of padding on 64 bit builds (also removes 8 bytes from task_struct) Signed-off-by: Richard Kennedy Signed-off-by: Ingo Molnar --- include/linux/sched.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include') diff --git a/include/linux/sched.h b/include/linux/sched.h index 5a8058e44f58..08a87b5f29e1 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1010,8 +1010,8 @@ struct sched_entity { struct sched_rt_entity { struct list_head run_list; - unsigned int time_slice; unsigned long timeout; + unsigned int time_slice; int nr_cpus_allowed; struct sched_rt_entity *back; -- cgit v1.2.3 From 3fb669dd6ec11e14819c0114a0e68a9ddcec65e1 Mon Sep 17 00:00:00 2001 From: Richard Kennedy Date: Fri, 1 Aug 2008 13:36:28 +0100 Subject: reorder struct prop_local_single to remove padding on 64 bit builds reorder structure to remove 8 bytes of padding on 64 bit builds (also removes 8 bytes from task_struct) Signed-off-by: Richard Kennedy Cc: peterz@infradead.org Signed-off-by: Ingo Molnar --- include/linux/proportions.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include') diff --git a/include/linux/proportions.h b/include/linux/proportions.h index 5afc1b23346d..cf793bbbd05e 100644 --- a/include/linux/proportions.h +++ b/include/linux/proportions.h @@ -104,8 +104,8 @@ struct prop_local_single { * snapshot of the last seen global state * and a lock protecting this state */ - int shift; unsigned long period; + int shift; spinlock_t lock; /* protect the snapshot state */ }; -- cgit v1.2.3 From 65eb3dc609dec17deea48dcd4de2e549d29a9824 Mon Sep 17 00:00:00 2001 From: Kevin Diggs Date: Tue, 26 Aug 2008 10:26:54 +0200 Subject: sched: add kernel doc for the completion, fix kernel-doc-nano-HOWTO.txt This patch adds kernel doc for the completion feature. An error in the split-man.pl PERL snippet in kernel-doc-nano-HOWTO.txt is also fixed. Signed-off-by: Kevin Diggs Signed-off-by: Ingo Molnar --- Documentation/kernel-doc-nano-HOWTO.txt | 4 +-- include/linux/completion.h | 41 ++++++++++++++++++++++++ kernel/sched.c | 56 +++++++++++++++++++++++++++++++++ 3 files changed, 99 insertions(+), 2 deletions(-) (limited to 'include') diff --git a/Documentation/kernel-doc-nano-HOWTO.txt b/Documentation/kernel-doc-nano-HOWTO.txt index 0bd32748a467..c6841eee9598 100644 --- a/Documentation/kernel-doc-nano-HOWTO.txt +++ b/Documentation/kernel-doc-nano-HOWTO.txt @@ -168,10 +168,10 @@ if ($#ARGV < 0) { mkdir $ARGV[0],0777; $state = 0; while () { - if (/^\.TH \"[^\"]*\" 4 \"([^\"]*)\"/) { + if (/^\.TH \"[^\"]*\" 9 \"([^\"]*)\"/) { if ($state == 1) { close OUT } $state = 1; - $fn = "$ARGV[0]/$1.4"; + $fn = "$ARGV[0]/$1.9"; print STDERR "Creating $fn\n"; open OUT, ">$fn" or die "can't open $fn: $!\n"; print OUT $_; diff --git a/include/linux/completion.h b/include/linux/completion.h index 02ef8835999c..4a6b604ef7e4 100644 --- a/include/linux/completion.h +++ b/include/linux/completion.h @@ -10,6 +10,18 @@ #include +/** + * struct completion - structure used to maintain state for a "completion" + * + * This is the opaque structure used to maintain the state for a "completion". + * Completions currently use a FIFO to queue threads that have to wait for + * the "completion" event. + * + * See also: complete(), wait_for_completion() (and friends _timeout, + * _interruptible, _interruptible_timeout, and _killable), init_completion(), + * and macros DECLARE_COMPLETION(), DECLARE_COMPLETION_ONSTACK(), and + * INIT_COMPLETION(). + */ struct completion { unsigned int done; wait_queue_head_t wait; @@ -21,6 +33,14 @@ struct completion { #define COMPLETION_INITIALIZER_ONSTACK(work) \ ({ init_completion(&work); work; }) +/** + * DECLARE_COMPLETION: - declare and initialize a completion structure + * @work: identifier for the completion structure + * + * This macro declares and initializes a completion structure. Generally used + * for static declarations. You should use the _ONSTACK variant for automatic + * variables. + */ #define DECLARE_COMPLETION(work) \ struct completion work = COMPLETION_INITIALIZER(work) @@ -29,6 +49,13 @@ struct completion { * completions - so we use the _ONSTACK() variant for those that * are on the kernel stack: */ +/** + * DECLARE_COMPLETION_ONSTACK: - declare and initialize a completion structure + * @work: identifier for the completion structure + * + * This macro declares and initializes a completion structure on the kernel + * stack. + */ #ifdef CONFIG_LOCKDEP # define DECLARE_COMPLETION_ONSTACK(work) \ struct completion work = COMPLETION_INITIALIZER_ONSTACK(work) @@ -36,6 +63,13 @@ struct completion { # define DECLARE_COMPLETION_ONSTACK(work) DECLARE_COMPLETION(work) #endif +/** + * init_completion: - Initialize a dynamically allocated completion + * @x: completion structure that is to be initialized + * + * This inline function will initialize a dynamically created completion + * structure. + */ static inline void init_completion(struct completion *x) { x->done = 0; @@ -55,6 +89,13 @@ extern bool completion_done(struct completion *x); extern void complete(struct completion *); extern void complete_all(struct completion *); +/** + * INIT_COMPLETION: - reinitialize a completion structure + * @x: completion structure to be reinitialized + * + * This macro should be used to reinitialize a completion structure so it can + * be reused. This is especially important after complete_all() is used. + */ #define INIT_COMPLETION(x) ((x).done = 0) diff --git a/kernel/sched.c b/kernel/sched.c index 29e2ec0bd831..93f5ea08be97 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -4565,6 +4565,15 @@ __wake_up_sync(wait_queue_head_t *q, unsigned int mode, int nr_exclusive) } EXPORT_SYMBOL_GPL(__wake_up_sync); /* For internal use only */ +/** + * complete: - signals a single thread waiting on this completion + * @x: holds the state of this particular completion + * + * This will wake up a single thread waiting on this completion. Threads will be + * awakened in the same order in which they were queued. + * + * See also complete_all(), wait_for_completion() and related routines. + */ void complete(struct completion *x) { unsigned long flags; @@ -4576,6 +4585,12 @@ void complete(struct completion *x) } EXPORT_SYMBOL(complete); +/** + * complete_all: - signals all threads waiting on this completion + * @x: holds the state of this particular completion + * + * This will wake up all threads waiting on this particular completion event. + */ void complete_all(struct completion *x) { unsigned long flags; @@ -4624,12 +4639,31 @@ wait_for_common(struct completion *x, long timeout, int state) return timeout; } +/** + * wait_for_completion: - waits for completion of a task + * @x: holds the state of this particular completion + * + * This waits to be signaled for completion of a specific task. It is NOT + * interruptible and there is no timeout. + * + * See also similar routines (i.e. wait_for_completion_timeout()) with timeout + * and interrupt capability. Also see complete(). + */ void __sched wait_for_completion(struct completion *x) { wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_UNINTERRUPTIBLE); } EXPORT_SYMBOL(wait_for_completion); +/** + * wait_for_completion_timeout: - waits for completion of a task (w/timeout) + * @x: holds the state of this particular completion + * @timeout: timeout value in jiffies + * + * This waits for either a completion of a specific task to be signaled or for a + * specified timeout to expire. The timeout is in jiffies. It is not + * interruptible. + */ unsigned long __sched wait_for_completion_timeout(struct completion *x, unsigned long timeout) { @@ -4637,6 +4671,13 @@ wait_for_completion_timeout(struct completion *x, unsigned long timeout) } EXPORT_SYMBOL(wait_for_completion_timeout); +/** + * wait_for_completion_interruptible: - waits for completion of a task (w/intr) + * @x: holds the state of this particular completion + * + * This waits for completion of a specific task to be signaled. It is + * interruptible. + */ int __sched wait_for_completion_interruptible(struct completion *x) { long t = wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_INTERRUPTIBLE); @@ -4646,6 +4687,14 @@ int __sched wait_for_completion_interruptible(struct completion *x) } EXPORT_SYMBOL(wait_for_completion_interruptible); +/** + * wait_for_completion_interruptible_timeout: - waits for completion (w/(to,intr)) + * @x: holds the state of this particular completion + * @timeout: timeout value in jiffies + * + * This waits for either a completion of a specific task to be signaled or for a + * specified timeout to expire. It is interruptible. The timeout is in jiffies. + */ unsigned long __sched wait_for_completion_interruptible_timeout(struct completion *x, unsigned long timeout) @@ -4654,6 +4703,13 @@ wait_for_completion_interruptible_timeout(struct completion *x, } EXPORT_SYMBOL(wait_for_completion_interruptible_timeout); +/** + * wait_for_completion_killable: - waits for completion of a task (killable) + * @x: holds the state of this particular completion + * + * This waits to be signaled for completion of a specific task. It can be + * interrupted by a kill signal. + */ int __sched wait_for_completion_killable(struct completion *x) { long t = wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_KILLABLE); -- cgit v1.2.3 From e545a6140b698b2494daf0b32107bdcc5e901390 Mon Sep 17 00:00:00 2001 From: Manfred Spraul Date: Sun, 7 Sep 2008 16:57:22 +0200 Subject: kernel/cpu.c: create a CPU_STARTING cpu_chain notifier Right now, there is no notifier that is called on a new cpu, before the new cpu begins processing interrupts/softirqs. Various kernel function would need that notification, e.g. kvm works around by calling smp_call_function_single(), rcu polls cpu_online_map. The patch adds a CPU_STARTING notification. It also adds a helper function that sends the message to all cpu_chain handlers. Tested on x86-64. All other archs are untested. Especially on sparc, I'm not sure if I got it right. Signed-off-by: Manfred Spraul Signed-off-by: Ingo Molnar --- arch/alpha/kernel/smp.c | 3 +++ arch/arm/kernel/smp.c | 1 + arch/cris/arch-v32/kernel/smp.c | 1 + arch/ia64/kernel/smpboot.c | 1 + arch/m32r/kernel/smpboot.c | 2 ++ arch/mips/kernel/smp.c | 2 ++ arch/powerpc/kernel/smp.c | 1 + arch/s390/kernel/smp.c | 2 ++ arch/sh/kernel/smp.c | 2 ++ arch/sparc/kernel/sun4d_smp.c | 1 + arch/sparc/kernel/sun4m_smp.c | 2 ++ arch/um/kernel/smp.c | 1 + arch/x86/kernel/smpboot.c | 1 + arch/x86/mach-voyager/voyager_smp.c | 2 ++ include/linux/cpu.h | 1 + include/linux/notifier.h | 10 +++++++++- kernel/cpu.c | 19 +++++++++++++++++++ 17 files changed, 51 insertions(+), 1 deletion(-) (limited to 'include') diff --git a/arch/alpha/kernel/smp.c b/arch/alpha/kernel/smp.c index 83df541650fc..06b6fdab639f 100644 --- a/arch/alpha/kernel/smp.c +++ b/arch/alpha/kernel/smp.c @@ -149,6 +149,9 @@ smp_callin(void) atomic_inc(&init_mm.mm_count); current->active_mm = &init_mm; + /* inform the notifiers about the new cpu */ + notify_cpu_starting(cpuid); + /* Must have completely accurate bogos. */ local_irq_enable(); diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c index e9842f6767f9..e42a749a56dd 100644 --- a/arch/arm/kernel/smp.c +++ b/arch/arm/kernel/smp.c @@ -277,6 +277,7 @@ asmlinkage void __cpuinit secondary_start_kernel(void) /* * Enable local interrupts. */ + notify_cpu_starting(cpu); local_irq_enable(); local_fiq_enable(); diff --git a/arch/cris/arch-v32/kernel/smp.c b/arch/cris/arch-v32/kernel/smp.c index 952a24b2f5a9..52e16c6436f9 100644 --- a/arch/cris/arch-v32/kernel/smp.c +++ b/arch/cris/arch-v32/kernel/smp.c @@ -178,6 +178,7 @@ void __init smp_callin(void) unmask_irq(IPI_INTR_VECT); unmask_irq(TIMER0_INTR_VECT); preempt_disable(); + notify_cpu_starting(cpu); local_irq_enable(); cpu_set(cpu, cpu_online_map); diff --git a/arch/ia64/kernel/smpboot.c b/arch/ia64/kernel/smpboot.c index bcea81e432fd..333b58f218d0 100644 --- a/arch/ia64/kernel/smpboot.c +++ b/arch/ia64/kernel/smpboot.c @@ -401,6 +401,7 @@ smp_callin (void) spin_lock(&vector_lock); /* Setup the per cpu irq handling data structures */ __setup_vector_irq(cpuid); + notify_cpu_starting(cpuid); cpu_set(cpuid, cpu_online_map); per_cpu(cpu_state, cpuid) = CPU_ONLINE; spin_unlock(&vector_lock); diff --git a/arch/m32r/kernel/smpboot.c b/arch/m32r/kernel/smpboot.c index 2c03ac1d005f..fc2994811f15 100644 --- a/arch/m32r/kernel/smpboot.c +++ b/arch/m32r/kernel/smpboot.c @@ -498,6 +498,8 @@ static void __init smp_online(void) { int cpu_id = smp_processor_id(); + notify_cpu_starting(cpu_id); + local_irq_enable(); /* Get our bogomips. */ diff --git a/arch/mips/kernel/smp.c b/arch/mips/kernel/smp.c index 4410f172b8ab..7b59cfb7e602 100644 --- a/arch/mips/kernel/smp.c +++ b/arch/mips/kernel/smp.c @@ -121,6 +121,8 @@ asmlinkage __cpuinit void start_secondary(void) cpu = smp_processor_id(); cpu_data[cpu].udelay_val = loops_per_jiffy; + notify_cpu_starting(cpu); + mp_ops->smp_finish(); set_cpu_sibling_map(cpu); diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c index 5337ca7bb649..c27b10a1bd79 100644 --- a/arch/powerpc/kernel/smp.c +++ b/arch/powerpc/kernel/smp.c @@ -453,6 +453,7 @@ int __devinit start_secondary(void *unused) secondary_cpu_time_init(); ipi_call_lock(); + notify_cpu_starting(cpu); cpu_set(cpu, cpu_online_map); /* Update sibling maps */ base = cpu_first_thread_in_core(cpu); diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c index 00b9b4dec5eb..9e8b1f9b8f4d 100644 --- a/arch/s390/kernel/smp.c +++ b/arch/s390/kernel/smp.c @@ -585,6 +585,8 @@ int __cpuinit start_secondary(void *cpuvoid) /* Enable pfault pseudo page faults on this cpu. */ pfault_init(); + /* call cpu notifiers */ + notify_cpu_starting(smp_processor_id()); /* Mark this cpu as online */ spin_lock(&call_lock); cpu_set(smp_processor_id(), cpu_online_map); diff --git a/arch/sh/kernel/smp.c b/arch/sh/kernel/smp.c index 60c50841143e..001778f9adaf 100644 --- a/arch/sh/kernel/smp.c +++ b/arch/sh/kernel/smp.c @@ -82,6 +82,8 @@ asmlinkage void __cpuinit start_secondary(void) preempt_disable(); + notify_cpu_starting(smp_processor_id()); + local_irq_enable(); calibrate_delay(); diff --git a/arch/sparc/kernel/sun4d_smp.c b/arch/sparc/kernel/sun4d_smp.c index 69596402a500..446767e8f569 100644 --- a/arch/sparc/kernel/sun4d_smp.c +++ b/arch/sparc/kernel/sun4d_smp.c @@ -88,6 +88,7 @@ void __init smp4d_callin(void) local_flush_cache_all(); local_flush_tlb_all(); + notify_cpu_starting(cpuid); /* * Unblock the master CPU _only_ when the scheduler state * of all secondary CPUs will be up-to-date, so after diff --git a/arch/sparc/kernel/sun4m_smp.c b/arch/sparc/kernel/sun4m_smp.c index a14a76ac7f36..9964890dc1db 100644 --- a/arch/sparc/kernel/sun4m_smp.c +++ b/arch/sparc/kernel/sun4m_smp.c @@ -71,6 +71,8 @@ void __cpuinit smp4m_callin(void) local_flush_cache_all(); local_flush_tlb_all(); + notify_cpu_starting(cpuid); + /* Get our local ticker going. */ smp_setup_percpu_timer(); diff --git a/arch/um/kernel/smp.c b/arch/um/kernel/smp.c index be2d50c3aa95..045772142844 100644 --- a/arch/um/kernel/smp.c +++ b/arch/um/kernel/smp.c @@ -85,6 +85,7 @@ static int idle_proc(void *cpup) while (!cpu_isset(cpu, smp_commenced_mask)) cpu_relax(); + notify_cpu_starting(cpu); cpu_set(cpu, cpu_online_map); default_idle(); return 0; diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c index 7985c5b3f916..0b8261c3cac2 100644 --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -257,6 +257,7 @@ static void __cpuinit smp_callin(void) end_local_APIC_setup(); map_cpu_to_logical_apicid(); + notify_cpu_starting(cpuid); /* * Get our bogomips. * diff --git a/arch/x86/mach-voyager/voyager_smp.c b/arch/x86/mach-voyager/voyager_smp.c index ee0fba092157..199a5f4a873c 100644 --- a/arch/x86/mach-voyager/voyager_smp.c +++ b/arch/x86/mach-voyager/voyager_smp.c @@ -448,6 +448,8 @@ static void __init start_secondary(void *unused) VDEBUG(("VOYAGER SMP: CPU%d, stack at about %p\n", cpuid, &cpuid)); + notify_cpu_starting(cpuid); + /* enable interrupts */ local_irq_enable(); diff --git a/include/linux/cpu.h b/include/linux/cpu.h index d7faf8808497..c2747ac2ae43 100644 --- a/include/linux/cpu.h +++ b/include/linux/cpu.h @@ -69,6 +69,7 @@ static inline void unregister_cpu_notifier(struct notifier_block *nb) #endif int cpu_up(unsigned int cpu); +void notify_cpu_starting(unsigned int cpu); extern void cpu_hotplug_init(void); extern void cpu_maps_update_begin(void); extern void cpu_maps_update_done(void); diff --git a/include/linux/notifier.h b/include/linux/notifier.h index da2698b0fdd1..b86fa2ffca0c 100644 --- a/include/linux/notifier.h +++ b/include/linux/notifier.h @@ -213,9 +213,16 @@ static inline int notifier_to_errno(int ret) #define CPU_DOWN_FAILED 0x0006 /* CPU (unsigned)v NOT going down */ #define CPU_DEAD 0x0007 /* CPU (unsigned)v dead */ #define CPU_DYING 0x0008 /* CPU (unsigned)v not running any task, - * not handling interrupts, soon dead */ + * not handling interrupts, soon dead. + * Called on the dying cpu, interrupts + * are already disabled. Must not + * sleep, must not fail */ #define CPU_POST_DEAD 0x0009 /* CPU (unsigned)v dead, cpu_hotplug * lock is dropped */ +#define CPU_STARTING 0x000A /* CPU (unsigned)v soon running. + * Called on the new cpu, just before + * enabling interrupts. Must not sleep, + * must not fail */ /* Used for CPU hotplug events occuring while tasks are frozen due to a suspend * operation in progress @@ -229,6 +236,7 @@ static inline int notifier_to_errno(int ret) #define CPU_DOWN_FAILED_FROZEN (CPU_DOWN_FAILED | CPU_TASKS_FROZEN) #define CPU_DEAD_FROZEN (CPU_DEAD | CPU_TASKS_FROZEN) #define CPU_DYING_FROZEN (CPU_DYING | CPU_TASKS_FROZEN) +#define CPU_STARTING_FROZEN (CPU_STARTING | CPU_TASKS_FROZEN) /* Hibernation and suspend events */ #define PM_HIBERNATION_PREPARE 0x0001 /* Going to hibernate */ diff --git a/kernel/cpu.c b/kernel/cpu.c index f17e9854c246..dc45f2459efb 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -453,6 +453,25 @@ out: } #endif /* CONFIG_PM_SLEEP_SMP */ +/** + * notify_cpu_starting(cpu) - call the CPU_STARTING notifiers + * @cpu: cpu that just started + * + * This function calls the cpu_chain notifiers with CPU_STARTING. + * It must be called by the arch code on the new cpu, before the new cpu + * enables interrupts and before the "boot" cpu returns from __cpu_up(). + */ +void notify_cpu_starting(unsigned int cpu) +{ + unsigned long val = CPU_STARTING; + +#ifdef CONFIG_PM_SLEEP_SMP + if (cpu_isset(cpu, frozen_cpus)) + val = CPU_STARTING_FROZEN; +#endif /* CONFIG_PM_SLEEP_SMP */ + raw_notifier_call_chain(&cpu_chain, val, (void *)(long)cpu); +} + #endif /* CONFIG_SMP */ /* -- cgit v1.2.3 From 15afe09bf496ae10c989e1a375a6b5da7bd3e16e Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Sat, 20 Sep 2008 23:38:02 +0200 Subject: sched: wakeup preempt when small overlap Lin Ming reported a 10% OLTP regression against 2.6.27-rc4. The difference seems to come from different preemption agressiveness, which affects the cache footprint of the workload and its effective cache trashing. Aggresively preempt a task if its avg overlap is very small, this should avoid the task going to sleep and find it still running when we schedule back to it - saving a wakeup. Reported-by: Lin Ming Signed-off-by: Peter Zijlstra Signed-off-by: Ingo Molnar --- include/linux/sched.h | 2 +- kernel/sched.c | 12 ++++++------ kernel/sched_fair.c | 13 ++++++++++--- kernel/sched_features.h | 1 + kernel/sched_idletask.c | 6 +++--- kernel/sched_rt.c | 2 +- 6 files changed, 22 insertions(+), 14 deletions(-) (limited to 'include') diff --git a/include/linux/sched.h b/include/linux/sched.h index b3b7a8f32477..d8e699b55858 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -897,7 +897,7 @@ struct sched_class { void (*yield_task) (struct rq *rq); int (*select_task_rq)(struct task_struct *p, int sync); - void (*check_preempt_curr) (struct rq *rq, struct task_struct *p); + void (*check_preempt_curr) (struct rq *rq, struct task_struct *p, int sync); struct task_struct * (*pick_next_task) (struct rq *rq); void (*put_prev_task) (struct rq *rq, struct task_struct *p); diff --git a/kernel/sched.c b/kernel/sched.c index 0d8905a1b8ca..ad9d39b021f8 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -604,9 +604,9 @@ struct rq { static DEFINE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues); -static inline void check_preempt_curr(struct rq *rq, struct task_struct *p) +static inline void check_preempt_curr(struct rq *rq, struct task_struct *p, int sync) { - rq->curr->sched_class->check_preempt_curr(rq, p); + rq->curr->sched_class->check_preempt_curr(rq, p, sync); } static inline int cpu_of(struct rq *rq) @@ -2282,7 +2282,7 @@ out_running: trace_mark(kernel_sched_wakeup, "pid %d state %ld ## rq %p task %p rq->curr %p", p->pid, p->state, rq, p, rq->curr); - check_preempt_curr(rq, p); + check_preempt_curr(rq, p, sync); p->state = TASK_RUNNING; #ifdef CONFIG_SMP @@ -2417,7 +2417,7 @@ void wake_up_new_task(struct task_struct *p, unsigned long clone_flags) trace_mark(kernel_sched_wakeup_new, "pid %d state %ld ## rq %p task %p rq->curr %p", p->pid, p->state, rq, p, rq->curr); - check_preempt_curr(rq, p); + check_preempt_curr(rq, p, 0); #ifdef CONFIG_SMP if (p->sched_class->task_wake_up) p->sched_class->task_wake_up(rq, p); @@ -2877,7 +2877,7 @@ static void pull_task(struct rq *src_rq, struct task_struct *p, * Note that idle threads have a prio of MAX_PRIO, for this test * to be always true for them. */ - check_preempt_curr(this_rq, p); + check_preempt_curr(this_rq, p, 0); } /* @@ -6007,7 +6007,7 @@ static int __migrate_task(struct task_struct *p, int src_cpu, int dest_cpu) set_task_cpu(p, dest_cpu); if (on_rq) { activate_task(rq_dest, p, 0); - check_preempt_curr(rq_dest, p); + check_preempt_curr(rq_dest, p, 0); } done: ret = 1; diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index a10ac0bcee64..7328383690f1 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -1331,7 +1331,7 @@ static inline int depth_se(struct sched_entity *se) /* * Preempt the current task with a newly woken task if needed: */ -static void check_preempt_wakeup(struct rq *rq, struct task_struct *p) +static void check_preempt_wakeup(struct rq *rq, struct task_struct *p, int sync) { struct task_struct *curr = rq->curr; struct cfs_rq *cfs_rq = task_cfs_rq(curr); @@ -1367,6 +1367,13 @@ static void check_preempt_wakeup(struct rq *rq, struct task_struct *p) if (!sched_feat(WAKEUP_PREEMPT)) return; + if (sched_feat(WAKEUP_OVERLAP) && sync && + se->avg_overlap < sysctl_sched_migration_cost && + pse->avg_overlap < sysctl_sched_migration_cost) { + resched_task(curr); + return; + } + /* * preemption test can be made between sibling entities who are in the * same cfs_rq i.e who have a common parent. Walk up the hierarchy of @@ -1649,7 +1656,7 @@ static void prio_changed_fair(struct rq *rq, struct task_struct *p, if (p->prio > oldprio) resched_task(rq->curr); } else - check_preempt_curr(rq, p); + check_preempt_curr(rq, p, 0); } /* @@ -1666,7 +1673,7 @@ static void switched_to_fair(struct rq *rq, struct task_struct *p, if (running) resched_task(rq->curr); else - check_preempt_curr(rq, p); + check_preempt_curr(rq, p, 0); } /* Account for a task changing its policy or group. diff --git a/kernel/sched_features.h b/kernel/sched_features.h index 9353ca78154e..bf027a7accf8 100644 --- a/kernel/sched_features.h +++ b/kernel/sched_features.h @@ -11,3 +11,4 @@ SCHED_FEAT(ASYM_GRAN, 1) SCHED_FEAT(LB_BIAS, 1) SCHED_FEAT(LB_WAKEUP_UPDATE, 1) SCHED_FEAT(ASYM_EFF_LOAD, 1) +SCHED_FEAT(WAKEUP_OVERLAP, 1) diff --git a/kernel/sched_idletask.c b/kernel/sched_idletask.c index 3a4f92dbbe66..dec4ccabe2f5 100644 --- a/kernel/sched_idletask.c +++ b/kernel/sched_idletask.c @@ -14,7 +14,7 @@ static int select_task_rq_idle(struct task_struct *p, int sync) /* * Idle tasks are unconditionally rescheduled: */ -static void check_preempt_curr_idle(struct rq *rq, struct task_struct *p) +static void check_preempt_curr_idle(struct rq *rq, struct task_struct *p, int sync) { resched_task(rq->idle); } @@ -76,7 +76,7 @@ static void switched_to_idle(struct rq *rq, struct task_struct *p, if (running) resched_task(rq->curr); else - check_preempt_curr(rq, p); + check_preempt_curr(rq, p, 0); } static void prio_changed_idle(struct rq *rq, struct task_struct *p, @@ -93,7 +93,7 @@ static void prio_changed_idle(struct rq *rq, struct task_struct *p, if (p->prio > oldprio) resched_task(rq->curr); } else - check_preempt_curr(rq, p); + check_preempt_curr(rq, p, 0); } /* diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c index 552310798dad..6d2d0a5d030b 100644 --- a/kernel/sched_rt.c +++ b/kernel/sched_rt.c @@ -783,7 +783,7 @@ static void check_preempt_equal_prio(struct rq *rq, struct task_struct *p) /* * Preempt the current task with a newly woken task if needed: */ -static void check_preempt_curr_rt(struct rq *rq, struct task_struct *p) +static void check_preempt_curr_rt(struct rq *rq, struct task_struct *p, int sync) { if (p->prio < rq->curr->prio) { resched_task(rq->curr); -- cgit v1.2.3