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From: Hao Xu <haoxu@linux.alibaba.com>
To: Jens Axboe <axboe@kernel.dk>
Cc: io-uring@vger.kernel.org, Pavel Begunkov <asml.silence@gmail.com>,
	Joseph Qi <joseph.qi@linux.alibaba.com>
Subject: [PATCH v2] io-wq: simplify code in __io_worker_busy
Date: Mon,  5 Apr 2021 15:36:22 +0800	[thread overview]
Message-ID: <1617608182-202901-1-git-send-email-haoxu@linux.alibaba.com> (raw)
In-Reply-To: <91175ea9-950a-868b-bddf-dfe4c0184225@gmail.com>

leverage xor to simplify code in __io_worker_busy

Signed-off-by: Hao Xu <haoxu@linux.alibaba.com>
---

I thought about [IO_WQ_ACCT_UNBOUND + IO_WQ_ACCT_BOUND - index], but it
is not antithetical, so I finally choose to calculate two indexes
respectively.

 fs/io-wq.c | 14 +++++---------
 1 file changed, 5 insertions(+), 9 deletions(-)

diff --git a/fs/io-wq.c b/fs/io-wq.c
index 433c4d3c3c1c..7ec2948838ca 100644
--- a/fs/io-wq.c
+++ b/fs/io-wq.c
@@ -292,16 +292,12 @@ static void __io_worker_busy(struct io_wqe *wqe, struct io_worker *worker,
 	worker_bound = (worker->flags & IO_WORKER_F_BOUND) != 0;
 	work_bound = (work->flags & IO_WQ_WORK_UNBOUND) == 0;
 	if (worker_bound != work_bound) {
+		int index0 = work_bound ? IO_WQ_ACCT_UNBOUND : IO_WQ_ACCT_BOUND;
+		int index1 = work_bound ? IO_WQ_ACCT_BOUND : IO_WQ_ACCT_UNBOUND;
 		io_wqe_dec_running(worker);
-		if (work_bound) {
-			worker->flags |= IO_WORKER_F_BOUND;
-			wqe->acct[IO_WQ_ACCT_UNBOUND].nr_workers--;
-			wqe->acct[IO_WQ_ACCT_BOUND].nr_workers++;
-		} else {
-			worker->flags &= ~IO_WORKER_F_BOUND;
-			wqe->acct[IO_WQ_ACCT_UNBOUND].nr_workers++;
-			wqe->acct[IO_WQ_ACCT_BOUND].nr_workers--;
-		}
+		worker->flags ^= IO_WORKER_F_BOUND;
+		wqe->acct[index0].nr_workers--;
+		wqe->acct[index1].nr_workers++;
 		io_wqe_inc_running(worker);
 	 }
 }
-- 
1.8.3.1


      parent reply	other threads:[~2021-04-05  7:36 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-04-02 10:18 [PATCH] io-wq: simplify code in __io_worker_busy Hao Xu
2021-04-02 10:38 ` Pavel Begunkov
2021-04-04 19:17   ` Jens Axboe
2021-04-05  7:53     ` [PATCH v3] " Hao Xu
2021-04-05 21:46       ` Jens Axboe
2021-04-06  2:18         ` Hao Xu
2021-04-06  3:08         ` [PATCH v4] " Hao Xu
2021-04-06 15:36           ` Jens Axboe
2021-04-07 18:28           ` Pavel Begunkov
2021-04-05  7:36   ` Hao Xu [this message]

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