From a2e7a7eb2fea109891ffff90f947e8306080a2a3 Mon Sep 17 00:00:00 2001 From: Mike Galbraith Date: Fri, 18 Sep 2009 09:19:25 +0200 Subject: sched: Remove unneeded indentation in sched_fair.c::place_entity() Signed-off-by: Mike Galbraith Cc: Peter Zijlstra LKML-Reference: <1253258365.22787.33.camel@marge.simson.net> Signed-off-by: Ingo Molnar --- kernel/sched_fair.c | 41 +++++++++++++++++++---------------------- 1 file changed, 19 insertions(+), 22 deletions(-) diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index 10d218ab69f2..29b35a7ec571 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -709,31 +709,28 @@ place_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int initial) if (initial && sched_feat(START_DEBIT)) vruntime += sched_vslice(cfs_rq, se); - if (!initial) { - /* sleeps upto a single latency don't count. */ - if (sched_feat(FAIR_SLEEPERS)) { - unsigned long thresh = sysctl_sched_latency; + /* sleeps up to a single latency don't count. */ + if (!initial && sched_feat(FAIR_SLEEPERS)) { + unsigned long thresh = sysctl_sched_latency; - /* - * Convert the sleeper threshold into virtual time. - * SCHED_IDLE is a special sub-class. We care about - * fairness only relative to other SCHED_IDLE tasks, - * all of which have the same weight. - */ - if (sched_feat(NORMALIZED_SLEEPER) && - (!entity_is_task(se) || - task_of(se)->policy != SCHED_IDLE)) - thresh = calc_delta_fair(thresh, se); + /* + * Convert the sleeper threshold into virtual time. + * SCHED_IDLE is a special sub-class. We care about + * fairness only relative to other SCHED_IDLE tasks, + * all of which have the same weight. + */ + if (sched_feat(NORMALIZED_SLEEPER) && (!entity_is_task(se) || + task_of(se)->policy != SCHED_IDLE)) + thresh = calc_delta_fair(thresh, se); - /* - * Halve their sleep time's effect, to allow - * for a gentler effect of sleepers: - */ - if (sched_feat(GENTLE_FAIR_SLEEPERS)) - thresh >>= 1; + /* + * Halve their sleep time's effect, to allow + * for a gentler effect of sleepers: + */ + if (sched_feat(GENTLE_FAIR_SLEEPERS)) + thresh >>= 1; - vruntime -= thresh; - } + vruntime -= thresh; } /* ensure we never gain time by being placed backwards. */ -- cgit v1.2.3-59-g8ed1b From 3f04e8cd5b24727a2500f8ab8f3de730ba47b02c Mon Sep 17 00:00:00 2001 From: Mike Galbraith Date: Sat, 19 Sep 2009 16:52:35 +0200 Subject: sched: Re-add lost cpu_allowed check to sched_fair.c::select_task_rq_fair() While doing some testing, I pinned mplayer, only to find it following X around like a puppy. Looking at commit c88d591, I found a cpu_allowed check that went AWOL. I plugged it back in where it looks like it needs to go, and now when I say "sit, stay!", mplayer obeys again. 'c88d591 sched: Merge select_task_rq_fair() and sched_balance_self()' accidentally dropped the check, causing wake_affine() to pull pinned tasks - put it back. [ v2: use a cheaper version from Peter ] Signed-off-by: Mike Galbraith Acked-by: Peter Zijlstra LKML-Reference: Signed-off-by: Ingo Molnar --- kernel/sched_fair.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index 29b35a7ec571..566e3bb78ed9 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -1339,7 +1339,8 @@ static int select_task_rq_fair(struct task_struct *p, int sd_flag, int wake_flag int sync = wake_flags & WF_SYNC; if (sd_flag & SD_BALANCE_WAKE) { - if (sched_feat(AFFINE_WAKEUPS)) + if (sched_feat(AFFINE_WAKEUPS) && + cpumask_test_cpu(cpu, &p->cpus_allowed)) want_affine = 1; new_cpu = prev_cpu; } -- cgit v1.2.3-59-g8ed1b From 89f19f04dc72363d912fd007a399cb10310eff6e Mon Sep 17 00:00:00 2001 From: Andrew Morton Date: Sat, 19 Sep 2009 11:55:44 -0700 Subject: sched: Fix raciness in runqueue_is_locked() runqueue_is_locked() is unavoidably racy due to a poor interface design. It does cpu = get_cpu() ret = some_perpcu_thing(cpu); put_cpu(cpu); return ret; Its return value is unreliable. Fix. Signed-off-by: Andrew Morton Acked-by: Steven Rostedt Cc: Peter Zijlstra LKML-Reference: <200909191855.n8JItiko022148@imap1.linux-foundation.org> Signed-off-by: Ingo Molnar --- include/linux/sched.h | 2 +- kernel/sched.c | 10 ++-------- kernel/trace/trace.c | 8 +++++++- 3 files changed, 10 insertions(+), 10 deletions(-) diff --git a/include/linux/sched.h b/include/linux/sched.h index 8af3d249170e..cc37a3fa5065 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -257,7 +257,7 @@ extern asmlinkage void schedule_tail(struct task_struct *prev); extern void init_idle(struct task_struct *idle, int cpu); extern void init_idle_bootup_task(struct task_struct *idle); -extern int runqueue_is_locked(void); +extern int runqueue_is_locked(int cpu); extern void task_rq_unlock_wait(struct task_struct *p); extern cpumask_var_t nohz_cpu_mask; diff --git a/kernel/sched.c b/kernel/sched.c index faf4d463bbff..575fb0139038 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -681,15 +681,9 @@ inline void update_rq_clock(struct rq *rq) * This interface allows printk to be called with the runqueue lock * held and know whether or not it is OK to wake up the klogd. */ -int runqueue_is_locked(void) +int runqueue_is_locked(int cpu) { - int cpu = get_cpu(); - struct rq *rq = cpu_rq(cpu); - int ret; - - ret = spin_is_locked(&rq->lock); - put_cpu(); - return ret; + return spin_is_locked(&cpu_rq(cpu)->lock); } /* diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index fd52a19dd172..420232a1fbba 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -275,12 +275,18 @@ static DEFINE_SPINLOCK(tracing_start_lock); */ void trace_wake_up(void) { + int cpu; + + if (trace_flags & TRACE_ITER_BLOCK) + return; /* * The runqueue_is_locked() can fail, but this is the best we * have for now: */ - if (!(trace_flags & TRACE_ITER_BLOCK) && !runqueue_is_locked()) + cpu = get_cpu(); + if (!runqueue_is_locked(cpu)) wake_up(&trace_wait); + put_cpu(); } static int __init set_buf_size(char *str) -- cgit v1.2.3-59-g8ed1b From cb5fd13f1178dee4302646b2890d884c380160e1 Mon Sep 17 00:00:00 2001 From: Yong Zhang Date: Mon, 14 Sep 2009 20:20:16 +0800 Subject: sched: Fix potential NULL derference of doms_cur If CONFIG_CPUMASK_OFFSTACK is enabled but doms_cur alloc failed in arch_init_sched_domains(), doms_cur will move back to fallback_doms. But this time, fallback_doms has not been initialized yet. Signed-off-by: Yong Zhang Cc: a.p.zijlstra@chello.nl LKML-Reference: <1252930816-7672-1-git-send-email-yong.zhang0@gmail.com> Signed-off-by: Ingo Molnar --- kernel/sched.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/sched.c b/kernel/sched.c index 575fb0139038..1b900fb1c6e1 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -9165,6 +9165,7 @@ void __init sched_init_smp(void) cpumask_var_t non_isolated_cpus; alloc_cpumask_var(&non_isolated_cpus, GFP_KERNEL); + alloc_cpumask_var(&fallback_doms, GFP_KERNEL); #if defined(CONFIG_NUMA) sched_group_nodes_bycpu = kzalloc(nr_cpu_ids * sizeof(void **), @@ -9196,7 +9197,6 @@ void __init sched_init_smp(void) sched_init_granularity(); free_cpumask_var(non_isolated_cpus); - alloc_cpumask_var(&fallback_doms, GFP_KERNEL); init_sched_rt_class(); } #else -- cgit v1.2.3-59-g8ed1b From 0d721ceadbeaa24d7f9dd41b3e5e29912327a7e1 Mon Sep 17 00:00:00 2001 From: Peter Williams Date: Mon, 21 Sep 2009 01:31:53 +0000 Subject: sched: Simplify sys_sched_rr_get_interval() system call By removing the need for it to know details of scheduling classes. This allows PlugSched to define orthogonal scheduling classes. Signed-off-by: Peter Williams Acked-by: Peter Zijlstra Cc: Mike Galbraith LKML-Reference: <06d1b89ee15a0eef82d7.1253496713@mudlark.pw.nest> Signed-off-by: Ingo Molnar --- include/linux/sched.h | 2 ++ kernel/sched.c | 17 +---------------- kernel/sched_fair.c | 21 +++++++++++++++++++++ kernel/sched_idletask.c | 7 +++++++ kernel/sched_rt.c | 13 +++++++++++++ 5 files changed, 44 insertions(+), 16 deletions(-) diff --git a/include/linux/sched.h b/include/linux/sched.h index cc37a3fa5065..239c8e0dba9f 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1075,6 +1075,8 @@ struct sched_class { void (*prio_changed) (struct rq *this_rq, struct task_struct *task, int oldprio, int running); + unsigned int (*get_rr_interval) (struct task_struct *task); + #ifdef CONFIG_FAIR_GROUP_SCHED void (*moved_group) (struct task_struct *p); #endif diff --git a/kernel/sched.c b/kernel/sched.c index 1b900fb1c6e1..830967e18285 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -6819,23 +6819,8 @@ SYSCALL_DEFINE2(sched_rr_get_interval, pid_t, pid, if (retval) goto out_unlock; - /* - * Time slice is 0 for SCHED_FIFO tasks and for SCHED_OTHER - * tasks that are on an otherwise idle runqueue: - */ - time_slice = 0; - if (p->policy == SCHED_RR) { - time_slice = DEF_TIMESLICE; - } else if (p->policy != SCHED_FIFO) { - struct sched_entity *se = &p->se; - unsigned long flags; - struct rq *rq; + time_slice = p->sched_class->get_rr_interval(p); - rq = task_rq_lock(p, &flags); - if (rq->cfs.load.weight) - time_slice = NS_TO_JIFFIES(sched_slice(&rq->cfs, se)); - task_rq_unlock(rq, &flags); - } read_unlock(&tasklist_lock); jiffies_to_timespec(time_slice, &t); retval = copy_to_user(interval, &t, sizeof(t)) ? -EFAULT : 0; diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index 566e3bb78ed9..cd73738f0d5f 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -1938,6 +1938,25 @@ static void moved_group_fair(struct task_struct *p) } #endif +unsigned int get_rr_interval_fair(struct task_struct *task) +{ + struct sched_entity *se = &task->se; + unsigned long flags; + struct rq *rq; + unsigned int rr_interval = 0; + + /* + * Time slice is 0 for SCHED_OTHER tasks that are on an otherwise + * idle runqueue: + */ + rq = task_rq_lock(task, &flags); + if (rq->cfs.load.weight) + rr_interval = NS_TO_JIFFIES(sched_slice(&rq->cfs, se)); + task_rq_unlock(rq, &flags); + + return rr_interval; +} + /* * All the scheduling class methods: */ @@ -1966,6 +1985,8 @@ static const struct sched_class fair_sched_class = { .prio_changed = prio_changed_fair, .switched_to = switched_to_fair, + .get_rr_interval = get_rr_interval_fair, + #ifdef CONFIG_FAIR_GROUP_SCHED .moved_group = moved_group_fair, #endif diff --git a/kernel/sched_idletask.c b/kernel/sched_idletask.c index a8b448af004b..b133a28fcde3 100644 --- a/kernel/sched_idletask.c +++ b/kernel/sched_idletask.c @@ -97,6 +97,11 @@ static void prio_changed_idle(struct rq *rq, struct task_struct *p, check_preempt_curr(rq, p, 0); } +unsigned int get_rr_interval_idle(struct task_struct *task) +{ + return 0; +} + /* * Simple, special scheduling class for the per-CPU idle tasks: */ @@ -122,6 +127,8 @@ static const struct sched_class idle_sched_class = { .set_curr_task = set_curr_task_idle, .task_tick = task_tick_idle, + .get_rr_interval = get_rr_interval_idle, + .prio_changed = prio_changed_idle, .switched_to = switched_to_idle, diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c index 13de7126a6ab..a4d790cddb19 100644 --- a/kernel/sched_rt.c +++ b/kernel/sched_rt.c @@ -1734,6 +1734,17 @@ static void set_curr_task_rt(struct rq *rq) dequeue_pushable_task(rq, p); } +unsigned int get_rr_interval_rt(struct task_struct *task) +{ + /* + * Time slice is 0 for SCHED_FIFO tasks + */ + if (task->policy == SCHED_RR) + return DEF_TIMESLICE; + else + return 0; +} + static const struct sched_class rt_sched_class = { .next = &fair_sched_class, .enqueue_task = enqueue_task_rt, @@ -1762,6 +1773,8 @@ static const struct sched_class rt_sched_class = { .set_curr_task = set_curr_task_rt, .task_tick = task_tick_rt, + .get_rr_interval = get_rr_interval_rt, + .prio_changed = prio_changed_rt, .switched_to = switched_to_rt, }; -- cgit v1.2.3-59-g8ed1b