diff options
| -rw-r--r-- | include/linux/sched.h | 1 | ||||
| -rw-r--r-- | kernel/fork.c | 2 | ||||
| -rw-r--r-- | kernel/sched.c | 53 | ||||
| -rw-r--r-- | kernel/workqueue_sched.h | 16 |
4 files changed, 69 insertions, 3 deletions
diff --git a/include/linux/sched.h b/include/linux/sched.h index f118809c953f..edc3dd168d87 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1696,6 +1696,7 @@ extern void thread_group_times(struct task_struct *p, cputime_t *ut, cputime_t * #define PF_EXITING 0x00000004 /* getting shut down */ #define PF_EXITPIDONE 0x00000008 /* pi exit done on shut down */ #define PF_VCPU 0x00000010 /* I'm a virtual CPU */ +#define PF_WQ_WORKER 0x00000020 /* I'm a workqueue worker */ #define PF_FORKNOEXEC 0x00000040 /* forked but didn't exec */ #define PF_MCE_PROCESS 0x00000080 /* process policy on mce errors */ #define PF_SUPERPRIV 0x00000100 /* used super-user privileges */ diff --git a/kernel/fork.c b/kernel/fork.c index b6cce14ba047..a82a65cef741 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -907,7 +907,7 @@ static void copy_flags(unsigned long clone_flags, struct task_struct *p) { unsigned long new_flags = p->flags; - new_flags &= ~PF_SUPERPRIV; + new_flags &= ~(PF_SUPERPRIV | PF_WQ_WORKER); new_flags |= PF_FORKNOEXEC; new_flags |= PF_STARTING; p->flags = new_flags; diff --git a/kernel/sched.c b/kernel/sched.c index 96eafd5f345f..edd5a54b95da 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -77,6 +77,7 @@ #include <asm/irq_regs.h> #include "sched_cpupri.h" +#include "workqueue_sched.h" #define CREATE_TRACE_POINTS #include <trace/events/sched.h> @@ -2306,6 +2307,9 @@ static inline void ttwu_post_activation(struct task_struct *p, struct rq *rq, rq->idle_stamp = 0; } #endif + /* if a worker is waking up, notify workqueue */ + if ((p->flags & PF_WQ_WORKER) && success) + wq_worker_waking_up(p, cpu_of(rq)); } /** @@ -2414,6 +2418,37 @@ out: } /** + * try_to_wake_up_local - try to wake up a local task with rq lock held + * @p: the thread to be awakened + * + * Put @p on the run-queue if it's not alredy there. The caller must + * ensure that this_rq() is locked, @p is bound to this_rq() and not + * the current task. this_rq() stays locked over invocation. + */ +static void try_to_wake_up_local(struct task_struct *p) +{ + struct rq *rq = task_rq(p); + bool success = false; + + BUG_ON(rq != this_rq()); + BUG_ON(p == current); + lockdep_assert_held(&rq->lock); + + if (!(p->state & TASK_NORMAL)) + return; + + if (!p->se.on_rq) { + if (likely(!task_running(rq, p))) { + schedstat_inc(rq, ttwu_count); + schedstat_inc(rq, ttwu_local); + } + ttwu_activate(p, rq, false, false, true, ENQUEUE_WAKEUP); + success = true; + } + ttwu_post_activation(p, rq, 0, success); +} + +/** * wake_up_process - Wake up a specific process * @p: The process to be woken up. * @@ -3618,10 +3653,24 @@ need_resched_nonpreemptible: clear_tsk_need_resched(prev); if (prev->state && !(preempt_count() & PREEMPT_ACTIVE)) { - if (unlikely(signal_pending_state(prev->state, prev))) + if (unlikely(signal_pending_state(prev->state, prev))) { prev->state = TASK_RUNNING; - else + } else { + /* + * If a worker is going to sleep, notify and + * ask workqueue whether it wants to wake up a + * task to maintain concurrency. If so, wake + * up the task. + */ + if (prev->flags & PF_WQ_WORKER) { + struct task_struct *to_wakeup; + + to_wakeup = wq_worker_sleeping(prev, cpu); + if (to_wakeup) + try_to_wake_up_local(to_wakeup); + } deactivate_task(rq, prev, DEQUEUE_SLEEP); + } switch_count = &prev->nvcsw; } diff --git a/kernel/workqueue_sched.h b/kernel/workqueue_sched.h new file mode 100644 index 000000000000..af040babb742 --- /dev/null +++ b/kernel/workqueue_sched.h @@ -0,0 +1,16 @@ +/* + * kernel/workqueue_sched.h + * + * Scheduler hooks for concurrency managed workqueue. Only to be + * included from sched.c and workqueue.c. + */ +static inline void wq_worker_waking_up(struct task_struct *task, + unsigned int cpu) +{ +} + +static inline struct task_struct *wq_worker_sleeping(struct task_struct *task, + unsigned int cpu) +{ + return NULL; +} |