io-wq: briefly spin for new work after finishing work
To avoid going to sleep only to get woken shortly thereafter, spin briefly for new work upon completion of work. Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
24
fs/io-wq.c
24
fs/io-wq.c
@@ -491,26 +491,46 @@ next:
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} while (1);
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}
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static inline void io_worker_spin_for_work(struct io_wqe *wqe)
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{
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int i = 0;
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while (++i < 1000) {
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if (io_wqe_run_queue(wqe))
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break;
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if (need_resched())
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break;
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cpu_relax();
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}
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}
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static int io_wqe_worker(void *data)
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{
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struct io_worker *worker = data;
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struct io_wqe *wqe = worker->wqe;
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struct io_wq *wq = wqe->wq;
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bool did_work;
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io_worker_start(wqe, worker);
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did_work = false;
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while (!test_bit(IO_WQ_BIT_EXIT, &wq->state)) {
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set_current_state(TASK_INTERRUPTIBLE);
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loop:
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if (did_work)
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io_worker_spin_for_work(wqe);
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spin_lock_irq(&wqe->lock);
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if (io_wqe_run_queue(wqe)) {
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__set_current_state(TASK_RUNNING);
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io_worker_handle_work(worker);
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continue;
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did_work = true;
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goto loop;
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}
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did_work = false;
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/* drops the lock on success, retry */
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if (__io_worker_idle(wqe, worker)) {
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__release(&wqe->lock);
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continue;
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goto loop;
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}
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spin_unlock_irq(&wqe->lock);
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if (signal_pending(current))
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