From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753027AbcELTvI (ORCPT ); Thu, 12 May 2016 15:51:08 -0400 Received: from mail-wm0-f47.google.com ([74.125.82.47]:37672 "EHLO mail-wm0-f47.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932480AbcELTuA (ORCPT ); Thu, 12 May 2016 15:50:00 -0400 From: Matt Fleming To: Peter Zijlstra , Ingo Molnar Cc: linux-kernel@vger.kernel.org, Byungchul Park , Frederic Weisbecker , Luca Abeni , "Rafael J . Wysocki" , Rik van Riel , Thomas Gleixner , Wanpeng Li , Yuyang Du , Mel Gorman , Mike Galbraith , Matt Fleming Subject: [RFC][PATCH 2/5] sched: Add wrappers for lockdep_(un)pin_lock() Date: Thu, 12 May 2016 20:49:50 +0100 Message-Id: <1463082593-27777-3-git-send-email-matt@codeblueprint.co.uk> X-Mailer: git-send-email 2.7.3 In-Reply-To: <1463082593-27777-1-git-send-email-matt@codeblueprint.co.uk> References: <1463082593-27777-1-git-send-email-matt@codeblueprint.co.uk> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org In preparation for adding diagnostic checks to catch missing calls to update_rq_clock(), provide wrappers for (re)pinning and unpinning rq->lock. Because the pending diagnostic checks allow state to be maintained in rq_flags across pin contexts, swap the 'struct pin_cookie' arguments for 'struct rq_flags *'. Cc: Peter Zijlstra Cc: Ingo Molnar Cc: Mike Galbraith Cc: Mel Gorman Cc: Thomas Gleixner Cc: Frederic Weisbecker Cc: Wanpeng Li Cc: Luca Abeni Cc: Yuyang Du Cc: Byungchul Park Cc: Rik van Riel Cc: "Rafael J. Wysocki" Signed-off-by: Matt Fleming --- kernel/sched/core.c | 80 ++++++++++++++++++++++++------------------------ kernel/sched/deadline.c | 10 +++--- kernel/sched/fair.c | 6 ++-- kernel/sched/idle_task.c | 2 +- kernel/sched/rt.c | 6 ++-- kernel/sched/sched.h | 31 ++++++++++++++----- kernel/sched/stop_task.c | 2 +- 7 files changed, 76 insertions(+), 61 deletions(-) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 404c0784b1fc..dfdd8c3c083b 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -184,7 +184,7 @@ struct rq *__task_rq_lock(struct task_struct *p, struct rq_flags *rf) rq = task_rq(p); raw_spin_lock(&rq->lock); if (likely(rq == task_rq(p) && !task_on_rq_migrating(p))) { - rf->cookie = lockdep_pin_lock(&rq->lock); + rq_pin_lock(rq, rf); return rq; } raw_spin_unlock(&rq->lock); @@ -224,7 +224,7 @@ struct rq *task_rq_lock(struct task_struct *p, struct rq_flags *rf) * pair with the WMB to ensure we must then also see migrating. */ if (likely(rq == task_rq(p) && !task_on_rq_migrating(p))) { - rf->cookie = lockdep_pin_lock(&rq->lock); + rq_pin_lock(rq, rf); return rq; } raw_spin_unlock(&rq->lock); @@ -1183,9 +1183,9 @@ static int __set_cpus_allowed_ptr(struct task_struct *p, * OK, since we're going to drop the lock immediately * afterwards anyway. */ - lockdep_unpin_lock(&rq->lock, rf.cookie); + rq_unpin_lock(rq, &rf); rq = move_queued_task(rq, p, dest_cpu); - lockdep_repin_lock(&rq->lock, rf.cookie); + rq_repin_lock(rq, &rf); } out: task_rq_unlock(rq, p, &rf); @@ -1677,7 +1677,7 @@ static inline void ttwu_activate(struct rq *rq, struct task_struct *p, int en_fl * Mark the task runnable and perform wakeup-preemption. */ static void ttwu_do_wakeup(struct rq *rq, struct task_struct *p, int wake_flags, - struct pin_cookie cookie) + struct rq_flags *rf) { check_preempt_curr(rq, p, wake_flags); p->state = TASK_RUNNING; @@ -1689,9 +1689,9 @@ static void ttwu_do_wakeup(struct rq *rq, struct task_struct *p, int wake_flags, * Our task @p is fully woken up and running; so its safe to * drop the rq->lock, hereafter rq is only used for statistics. */ - lockdep_unpin_lock(&rq->lock, cookie); + rq_unpin_lock(rq, rf); p->sched_class->task_woken(rq, p); - lockdep_repin_lock(&rq->lock, cookie); + rq_repin_lock(rq, rf); } if (rq->idle_stamp) { @@ -1710,7 +1710,7 @@ static void ttwu_do_wakeup(struct rq *rq, struct task_struct *p, int wake_flags, static void ttwu_do_activate(struct rq *rq, struct task_struct *p, int wake_flags, - struct pin_cookie cookie) + struct rq_flags *rf) { int en_flags = ENQUEUE_WAKEUP; @@ -1725,7 +1725,7 @@ ttwu_do_activate(struct rq *rq, struct task_struct *p, int wake_flags, #endif ttwu_activate(rq, p, en_flags); - ttwu_do_wakeup(rq, p, wake_flags, cookie); + ttwu_do_wakeup(rq, p, wake_flags, rf); } /* @@ -1744,7 +1744,7 @@ static int ttwu_remote(struct task_struct *p, int wake_flags) if (task_on_rq_queued(p)) { /* check_preempt_curr() may use rq clock */ update_rq_clock(rq); - ttwu_do_wakeup(rq, p, wake_flags, rf.cookie); + ttwu_do_wakeup(rq, p, wake_flags, &rf); ret = 1; } __task_rq_unlock(rq, &rf); @@ -1757,15 +1757,15 @@ void sched_ttwu_pending(void) { struct rq *rq = this_rq(); struct llist_node *llist = llist_del_all(&rq->wake_list); - struct pin_cookie cookie; struct task_struct *p; unsigned long flags; + struct rq_flags rf; if (!llist) return; raw_spin_lock_irqsave(&rq->lock, flags); - cookie = lockdep_pin_lock(&rq->lock); + rq_pin_lock(rq, &rf); while (llist) { p = llist_entry(llist, struct task_struct, wake_entry); @@ -1774,10 +1774,10 @@ void sched_ttwu_pending(void) * See ttwu_queue(); we only call ttwu_queue_remote() when * its a x-cpu wakeup. */ - ttwu_do_activate(rq, p, WF_MIGRATED, cookie); + ttwu_do_activate(rq, p, WF_MIGRATED, &rf); } - lockdep_unpin_lock(&rq->lock, cookie); + rq_unpin_lock(rq, &rf); raw_spin_unlock_irqrestore(&rq->lock, flags); } @@ -1864,7 +1864,7 @@ bool cpus_share_cache(int this_cpu, int that_cpu) static void ttwu_queue(struct task_struct *p, int cpu, int wake_flags) { struct rq *rq = cpu_rq(cpu); - struct pin_cookie cookie; + struct rq_flags rf; #if defined(CONFIG_SMP) if (sched_feat(TTWU_QUEUE) && !cpus_share_cache(smp_processor_id(), cpu)) { @@ -1875,9 +1875,9 @@ static void ttwu_queue(struct task_struct *p, int cpu, int wake_flags) #endif raw_spin_lock(&rq->lock); - cookie = lockdep_pin_lock(&rq->lock); - ttwu_do_activate(rq, p, wake_flags, cookie); - lockdep_unpin_lock(&rq->lock, cookie); + rq_pin_lock(rq, &rf); + ttwu_do_activate(rq, p, wake_flags, &rf); + rq_unpin_lock(rq, &rf); raw_spin_unlock(&rq->lock); } @@ -2071,7 +2071,7 @@ out: * ensure that this_rq() is locked, @p is bound to this_rq() and not * the current task. */ -static void try_to_wake_up_local(struct task_struct *p, struct pin_cookie cookie) +static void try_to_wake_up_local(struct task_struct *p, struct rq_flags *rf) { struct rq *rq = task_rq(p); @@ -2088,11 +2088,11 @@ static void try_to_wake_up_local(struct task_struct *p, struct pin_cookie cookie * disabled avoiding further scheduler activity on it and we've * not yet picked a replacement task. */ - lockdep_unpin_lock(&rq->lock, cookie); + rq_unpin_lock(rq, rf); raw_spin_unlock(&rq->lock); raw_spin_lock(&p->pi_lock); raw_spin_lock(&rq->lock); - lockdep_repin_lock(&rq->lock, cookie); + rq_repin_lock(rq, rf); } if (!(p->state & TASK_NORMAL)) @@ -2103,7 +2103,7 @@ static void try_to_wake_up_local(struct task_struct *p, struct pin_cookie cookie if (!task_on_rq_queued(p)) ttwu_activate(rq, p, ENQUEUE_WAKEUP); - ttwu_do_wakeup(rq, p, 0, cookie); + ttwu_do_wakeup(rq, p, 0, rf); if (schedstat_enabled()) ttwu_stat(p, smp_processor_id(), 0); out: @@ -2531,9 +2531,9 @@ void wake_up_new_task(struct task_struct *p) * Nothing relies on rq->lock after this, so its fine to * drop it. */ - lockdep_unpin_lock(&rq->lock, rf.cookie); + rq_unpin_lock(rq, &rf); p->sched_class->task_woken(rq, p); - lockdep_repin_lock(&rq->lock, rf.cookie); + rq_repin_lock(rq, &rf); } #endif task_rq_unlock(rq, p, &rf); @@ -2798,7 +2798,7 @@ asmlinkage __visible void schedule_tail(struct task_struct *prev) */ static __always_inline struct rq * context_switch(struct rq *rq, struct task_struct *prev, - struct task_struct *next, struct pin_cookie cookie) + struct task_struct *next, struct rq_flags *rf) { struct mm_struct *mm, *oldmm; @@ -2830,7 +2830,7 @@ context_switch(struct rq *rq, struct task_struct *prev, * of the scheduler it's an obvious special-case), so we * do an early lockdep release here: */ - lockdep_unpin_lock(&rq->lock, cookie); + rq_unpin_lock(rq, rf); spin_release(&rq->lock.dep_map, 1, _THIS_IP_); /* Here we just switch the register state and the stack. */ @@ -3170,7 +3170,7 @@ static inline void schedule_debug(struct task_struct *prev) * Pick up the highest-prio task: */ static inline struct task_struct * -pick_next_task(struct rq *rq, struct task_struct *prev, struct pin_cookie cookie) +pick_next_task(struct rq *rq, struct task_struct *prev, struct rq_flags *rf) { const struct sched_class *class = &fair_sched_class; struct task_struct *p; @@ -3181,20 +3181,20 @@ pick_next_task(struct rq *rq, struct task_struct *prev, struct pin_cookie cookie */ if (likely(prev->sched_class == class && rq->nr_running == rq->cfs.h_nr_running)) { - p = fair_sched_class.pick_next_task(rq, prev, cookie); + p = fair_sched_class.pick_next_task(rq, prev, rf); if (unlikely(p == RETRY_TASK)) goto again; /* assumes fair_sched_class->next == idle_sched_class */ if (unlikely(!p)) - p = idle_sched_class.pick_next_task(rq, prev, cookie); + p = idle_sched_class.pick_next_task(rq, prev, rf); return p; } again: for_each_class(class) { - p = class->pick_next_task(rq, prev, cookie); + p = class->pick_next_task(rq, prev, rf); if (p) { if (unlikely(p == RETRY_TASK)) goto again; @@ -3248,7 +3248,7 @@ static void __sched notrace __schedule(bool preempt) { struct task_struct *prev, *next; unsigned long *switch_count; - struct pin_cookie cookie; + struct rq_flags rf; struct rq *rq; int cpu; @@ -3282,7 +3282,7 @@ static void __sched notrace __schedule(bool preempt) */ smp_mb__before_spinlock(); raw_spin_lock(&rq->lock); - cookie = lockdep_pin_lock(&rq->lock); + rq_pin_lock(rq, &rf); rq->clock_skip_update <<= 1; /* promote REQ to ACT */ @@ -3304,7 +3304,7 @@ static void __sched notrace __schedule(bool preempt) to_wakeup = wq_worker_sleeping(prev); if (to_wakeup) - try_to_wake_up_local(to_wakeup, cookie); + try_to_wake_up_local(to_wakeup, &rf); } } switch_count = &prev->nvcsw; @@ -3313,7 +3313,7 @@ static void __sched notrace __schedule(bool preempt) if (task_on_rq_queued(prev)) update_rq_clock(rq); - next = pick_next_task(rq, prev, cookie); + next = pick_next_task(rq, prev, &rf); clear_tsk_need_resched(prev); clear_preempt_need_resched(); rq->clock_skip_update = 0; @@ -3324,9 +3324,9 @@ static void __sched notrace __schedule(bool preempt) ++*switch_count; trace_sched_switch(preempt, prev, next); - rq = context_switch(rq, prev, next, cookie); /* unlocks the rq */ + rq = context_switch(rq, prev, next, &rf); /* unlocks the rq */ } else { - lockdep_unpin_lock(&rq->lock, cookie); + rq_unpin_lock(rq, &rf); raw_spin_unlock_irq(&rq->lock); } @@ -5411,7 +5411,7 @@ static void migrate_tasks(struct rq *dead_rq) { struct rq *rq = dead_rq; struct task_struct *next, *stop = rq->stop; - struct pin_cookie cookie; + struct rq_flags rf; int dest_cpu; /* @@ -5443,8 +5443,8 @@ static void migrate_tasks(struct rq *dead_rq) /* * pick_next_task assumes pinned rq->lock. */ - cookie = lockdep_pin_lock(&rq->lock); - next = pick_next_task(rq, &fake_task, cookie); + rq_pin_lock(rq, &rf); + next = pick_next_task(rq, &fake_task, &rf); BUG_ON(!next); next->sched_class->put_prev_task(rq, next); @@ -5457,7 +5457,7 @@ static void migrate_tasks(struct rq *dead_rq) * because !cpu_active at this point, which means load-balance * will not interfere. Also, stop-machine. */ - lockdep_unpin_lock(&rq->lock, cookie); + rq_unpin_lock(rq, &rf); raw_spin_unlock(&rq->lock); raw_spin_lock(&next->pi_lock); raw_spin_lock(&rq->lock); diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c index fcb7f0217ff4..9d2894895745 100644 --- a/kernel/sched/deadline.c +++ b/kernel/sched/deadline.c @@ -670,9 +670,9 @@ static enum hrtimer_restart dl_task_timer(struct hrtimer *timer) * Nothing relies on rq->lock after this, so its safe to drop * rq->lock. */ - lockdep_unpin_lock(&rq->lock, rf.cookie); + rq_unpin_lock(rq, &rf); push_dl_task(rq); - lockdep_repin_lock(&rq->lock, rf.cookie); + rq_repin_lock(rq, &rf); } #endif @@ -1126,7 +1126,7 @@ static struct sched_dl_entity *pick_next_dl_entity(struct rq *rq, } struct task_struct * -pick_next_task_dl(struct rq *rq, struct task_struct *prev, struct pin_cookie cookie) +pick_next_task_dl(struct rq *rq, struct task_struct *prev, struct rq_flags *rf) { struct sched_dl_entity *dl_se; struct task_struct *p; @@ -1141,9 +1141,9 @@ pick_next_task_dl(struct rq *rq, struct task_struct *prev, struct pin_cookie coo * disabled avoiding further scheduler activity on it and we're * being very careful to re-start the picking loop. */ - lockdep_unpin_lock(&rq->lock, cookie); + rq_unpin_lock(rq, rf); pull_dl_task(rq); - lockdep_repin_lock(&rq->lock, cookie); + rq_repin_lock(rq, rf); /* * pull_rt_task() can drop (and re-acquire) rq->lock; this * means a stop task can slip in, in which case we need to diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 02856647339d..7f776a99bde0 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -5594,7 +5594,7 @@ preempt: } static struct task_struct * -pick_next_task_fair(struct rq *rq, struct task_struct *prev, struct pin_cookie cookie) +pick_next_task_fair(struct rq *rq, struct task_struct *prev, struct rq_flags *rf) { struct cfs_rq *cfs_rq = &rq->cfs; struct sched_entity *se; @@ -5707,9 +5707,9 @@ idle: * further scheduler activity on it and we're being very careful to * re-start the picking loop. */ - lockdep_unpin_lock(&rq->lock, cookie); + rq_unpin_lock(rq, rf); new_tasks = idle_balance(rq); - lockdep_repin_lock(&rq->lock, cookie); + rq_repin_lock(rq, rf); /* * Because idle_balance() releases (and re-acquires) rq->lock, it is * possible for any higher priority task to appear. In that case we diff --git a/kernel/sched/idle_task.c b/kernel/sched/idle_task.c index 2ce5458bbe1d..f86dd339a7c9 100644 --- a/kernel/sched/idle_task.c +++ b/kernel/sched/idle_task.c @@ -24,7 +24,7 @@ static void check_preempt_curr_idle(struct rq *rq, struct task_struct *p, int fl } static struct task_struct * -pick_next_task_idle(struct rq *rq, struct task_struct *prev, struct pin_cookie cookie) +pick_next_task_idle(struct rq *rq, struct task_struct *prev, struct rq_flags *rf) { put_prev_task(rq, prev); diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c index d5690b722691..ab79812ee33e 100644 --- a/kernel/sched/rt.c +++ b/kernel/sched/rt.c @@ -1524,7 +1524,7 @@ static struct task_struct *_pick_next_task_rt(struct rq *rq) } static struct task_struct * -pick_next_task_rt(struct rq *rq, struct task_struct *prev, struct pin_cookie cookie) +pick_next_task_rt(struct rq *rq, struct task_struct *prev, struct rq_flags *rf) { struct task_struct *p; struct rt_rq *rt_rq = &rq->rt; @@ -1536,9 +1536,9 @@ pick_next_task_rt(struct rq *rq, struct task_struct *prev, struct pin_cookie coo * disabled avoiding further scheduler activity on it and we're * being very careful to re-start the picking loop. */ - lockdep_unpin_lock(&rq->lock, cookie); + rq_unpin_lock(rq, rf); pull_rt_task(rq); - lockdep_repin_lock(&rq->lock, cookie); + rq_repin_lock(rq, rf); /* * pull_rt_task() can drop (and re-acquire) rq->lock; this * means a dl or stop task can slip in, in which case we need diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index e51145e76807..cbeb830c7ac6 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -759,6 +759,26 @@ static inline void rq_clock_skip_update(struct rq *rq, bool skip) rq->clock_skip_update &= ~RQCF_REQ_SKIP; } +struct rq_flags { + unsigned long flags; + struct pin_cookie cookie; +}; + +static inline void rq_pin_lock(struct rq *rq, struct rq_flags *rf) +{ + rf->cookie = lockdep_pin_lock(&rq->lock); +} + +static inline void rq_unpin_lock(struct rq *rq, struct rq_flags *rf) +{ + lockdep_unpin_lock(&rq->lock, rf->cookie); +} + +static inline void rq_repin_lock(struct rq *rq, struct rq_flags *rf) +{ + lockdep_repin_lock(&rq->lock, rf->cookie); +} + #ifdef CONFIG_NUMA enum numa_topology_type { NUMA_DIRECT, @@ -1210,7 +1230,7 @@ struct sched_class { */ struct task_struct * (*pick_next_task) (struct rq *rq, struct task_struct *prev, - struct pin_cookie cookie); + struct rq_flags *rf); void (*put_prev_task) (struct rq *rq, struct task_struct *p); #ifdef CONFIG_SMP @@ -1458,11 +1478,6 @@ static inline void sched_rt_avg_update(struct rq *rq, u64 rt_delta) { } static inline void sched_avg_update(struct rq *rq) { } #endif -struct rq_flags { - unsigned long flags; - struct pin_cookie cookie; -}; - struct rq *__task_rq_lock(struct task_struct *p, struct rq_flags *rf) __acquires(rq->lock); struct rq *task_rq_lock(struct task_struct *p, struct rq_flags *rf) @@ -1472,7 +1487,7 @@ struct rq *task_rq_lock(struct task_struct *p, struct rq_flags *rf) static inline void __task_rq_unlock(struct rq *rq, struct rq_flags *rf) __releases(rq->lock) { - lockdep_unpin_lock(&rq->lock, rf->cookie); + rq_unpin_lock(rq, rf); raw_spin_unlock(&rq->lock); } @@ -1481,7 +1496,7 @@ task_rq_unlock(struct rq *rq, struct task_struct *p, struct rq_flags *rf) __releases(rq->lock) __releases(p->pi_lock) { - lockdep_unpin_lock(&rq->lock, rf->cookie); + rq_unpin_lock(rq, rf); raw_spin_unlock(&rq->lock); raw_spin_unlock_irqrestore(&p->pi_lock, rf->flags); } diff --git a/kernel/sched/stop_task.c b/kernel/sched/stop_task.c index 604297a08b3a..9f69fb630853 100644 --- a/kernel/sched/stop_task.c +++ b/kernel/sched/stop_task.c @@ -24,7 +24,7 @@ check_preempt_curr_stop(struct rq *rq, struct task_struct *p, int flags) } static struct task_struct * -pick_next_task_stop(struct rq *rq, struct task_struct *prev, struct pin_cookie cookie) +pick_next_task_stop(struct rq *rq, struct task_struct *prev, struct rq_flags *rf) { struct task_struct *stop = rq->stop; -- 2.7.3