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Mon, 02 Feb 2026 07:14:04 -0800 (PST) Message-ID: <8d675e0b-346d-44f1-b21b-e6c36d9230e9@kernel.dk> Date: Mon, 2 Feb 2026 08:14:03 -0700 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v1 1/2] io-wq: add exit-on-idle mode To: Li Chen , Pavel Begunkov , io-uring@vger.kernel.org, linux-kernel@vger.kernel.org References: <20260202143755.789114-1-me@linux.beauty> <20260202143755.789114-2-me@linux.beauty> Content-Language: en-US From: Jens Axboe In-Reply-To: <20260202143755.789114-2-me@linux.beauty> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 2/2/26 7:37 AM, Li Chen wrote: > diff --git a/io_uring/io-wq.c b/io_uring/io-wq.c > index 5d0928f37471..97e7eb847c6e 100644 > --- a/io_uring/io-wq.c > +++ b/io_uring/io-wq.c > @@ -655,6 +656,18 @@ static int io_wq_worker(void *data) > io_worker_handle_work(acct, worker); > > raw_spin_lock(&wq->lock); > + /* > + * If wq is marked idle-exit, drop this worker as soon as it > + * becomes idle. This is used to avoid keeping io-wq worker > + * threads around for tasks that no longer have any active > + * io_uring instances. > + */ > + if (test_bit(IO_WQ_BIT_EXIT_ON_IDLE, &wq->state)) { > + acct->nr_workers--; > + raw_spin_unlock(&wq->lock); > + __set_current_state(TASK_RUNNING); > + break; > + } > /* > * Last sleep timed out. Exit if we're not the last worker, > * or if someone modified our affinity. One more note - just add this test_bit() to the check right below, then you avoid duplicating all of that exit logic. They do the exact same thing. -- Jens Axboe