From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id CCACDC4332F for ; Wed, 24 Nov 2021 04:47:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230132AbhKXEuJ (ORCPT ); Tue, 23 Nov 2021 23:50:09 -0500 Received: from out30-131.freemail.mail.aliyun.com ([115.124.30.131]:43486 "EHLO out30-131.freemail.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229714AbhKXEuI (ORCPT ); Tue, 23 Nov 2021 23:50:08 -0500 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R161e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e04395;MF=haoxu@linux.alibaba.com;NM=1;PH=DS;RN=4;SR=0;TI=SMTPD_---0Uy45oE2_1637729208; Received: from e18g09479.et15sqa.tbsite.net(mailfrom:haoxu@linux.alibaba.com fp:SMTPD_---0Uy45oE2_1637729208) by smtp.aliyun-inc.com(127.0.0.1); Wed, 24 Nov 2021 12:46:58 +0800 From: Hao Xu To: Jens Axboe Cc: io-uring@vger.kernel.org, Pavel Begunkov , Joseph Qi Subject: [PATCH 8/9] io-wq: batch the handling of fixed worker private works Date: Wed, 24 Nov 2021 12:46:47 +0800 Message-Id: <20211124044648.142416-9-haoxu@linux.alibaba.com> X-Mailer: git-send-email 2.24.4 In-Reply-To: <20211124044648.142416-1-haoxu@linux.alibaba.com> References: <20211124044648.142416-1-haoxu@linux.alibaba.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org Let's reduce acct->lock contension by batching the handling of private work list for fixed_workers. Signed-off-by: Hao Xu --- fs/io-wq.c | 42 ++++++++++++++++++++++++++++++++---------- fs/io-wq.h | 5 +++++ 2 files changed, 37 insertions(+), 10 deletions(-) diff --git a/fs/io-wq.c b/fs/io-wq.c index b53019d4691d..097ea598bfe5 100644 --- a/fs/io-wq.c +++ b/fs/io-wq.c @@ -479,7 +479,7 @@ static void io_wait_on_hash(struct io_wqe_acct *acct, unsigned int hash) } static struct io_wq_work *io_get_next_work(struct io_wqe_acct *acct, - struct io_worker *worker) + struct io_worker *worker, bool needs_lock) __must_hold(acct->lock) { struct io_wq_work_node *node, *prev; @@ -487,14 +487,23 @@ static struct io_wq_work *io_get_next_work(struct io_wqe_acct *acct, unsigned int stall_hash = -1U; struct io_wqe *wqe = worker->wqe; + if (needs_lock) + raw_spin_lock(&acct->lock); wq_list_for_each(node, prev, &acct->work_list) { unsigned int hash; work = container_of(node, struct io_wq_work, list); + /* hash optimization doesn't work for fixed_workers for now */ + if (!needs_lock) { + wq_list_del(&acct->work_list, node, prev); + return work; + } + /* not hashed, can run anytime */ if (!io_wq_is_hashed(work)) { wq_list_del(&acct->work_list, node, prev); + raw_spin_unlock(&acct->lock); return work; } @@ -506,6 +515,7 @@ static struct io_wq_work *io_get_next_work(struct io_wqe_acct *acct, if (!test_and_set_bit(hash, &wqe->wq->hash->map)) { wqe->hash_tail[hash] = NULL; wq_list_cut(&acct->work_list, &tail->list, prev); + raw_spin_unlock(&acct->lock); return work; } if (stall_hash == -1U) @@ -515,15 +525,21 @@ static struct io_wq_work *io_get_next_work(struct io_wqe_acct *acct, } if (stall_hash != -1U) { + if (!needs_lock) + acct = &worker->acct; /* * Set this before dropping the lock to avoid racing with new * work being added and clearing the stalled bit. */ set_bit(IO_ACCT_STALLED_BIT, &acct->flags); - raw_spin_unlock(&acct->lock); + if (needs_lock) + raw_spin_unlock(&acct->lock); io_wait_on_hash(acct, stall_hash); - raw_spin_lock(&acct->lock); + if (needs_lock) + raw_spin_lock(&acct->lock); } + if (needs_lock) + raw_spin_unlock(&acct->lock); return NULL; } @@ -553,7 +569,8 @@ static void io_assign_current_work(struct io_worker *worker, static void io_wqe_enqueue(struct io_wqe *wqe, struct io_wq_work *work); -static void io_worker_handle_work(struct io_worker *worker, struct io_wqe_acct *acct) +static void io_worker_handle_work(struct io_worker *worker, struct io_wqe_acct *acct, + bool needs_lock) { struct io_wqe *wqe = worker->wqe; struct io_wq *wq = wqe->wq; @@ -569,9 +586,7 @@ static void io_worker_handle_work(struct io_worker *worker, struct io_wqe_acct * * can't make progress, any work completion or insertion will * clear the stalled flag. */ - raw_spin_lock(&acct->lock); - work = io_get_next_work(acct, worker); - raw_spin_unlock(&acct->lock); + work = io_get_next_work(acct, worker, needs_lock); if (work) { raw_spin_lock(&wqe->lock); __io_worker_busy(wqe, worker, work); @@ -604,7 +619,7 @@ static void io_worker_handle_work(struct io_worker *worker, struct io_wqe_acct * if (linked) io_wqe_enqueue(wqe, linked); - if (hash != -1U && !next_hashed) { + if (needs_lock && hash != -1U && !next_hashed) { clear_bit(hash, &wq->hash->map); clear_bit(IO_ACCT_STALLED_BIT, &acct->flags); if (wq_has_sleeper(&wq->hash->wait)) @@ -618,12 +633,19 @@ static void io_worker_handle_work(struct io_worker *worker, struct io_wqe_acct * static inline void io_worker_handle_private_work(struct io_worker *worker) { - io_worker_handle_work(worker, &worker->acct); + struct io_wqe_acct acct; + + raw_spin_lock(&worker->acct.lock); + acct = worker->acct; + wq_list_clean(&worker->acct.work_list); + worker->acct.nr_works = 0; + raw_spin_unlock(&worker->acct.lock); + io_worker_handle_work(worker, &acct, false); } static inline void io_worker_handle_public_work(struct io_worker *worker) { - io_worker_handle_work(worker, io_wqe_get_acct(worker)); + io_worker_handle_work(worker, io_wqe_get_acct(worker), true); } static int io_wqe_worker(void *data) diff --git a/fs/io-wq.h b/fs/io-wq.h index 41bf37674a49..7c330264172b 100644 --- a/fs/io-wq.h +++ b/fs/io-wq.h @@ -40,6 +40,11 @@ struct io_wq_work_list { (list)->first = NULL; \ } while (0) +static inline void wq_list_clean(struct io_wq_work_list *list) +{ + list->first = list->last = NULL; +} + static inline void wq_list_add_after(struct io_wq_work_node *node, struct io_wq_work_node *pos, struct io_wq_work_list *list) -- 2.24.4