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Thu, 11 Dec 2025 18:12:20 -0800 (PST) Message-ID: Date: Fri, 12 Dec 2025 10:12:15 +0800 Precedence: bulk X-Mailing-List: io-uring@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [RFC PATCH 2/2] io_uring: fix io may accumulation in poll mode To: Jens Axboe , asml.silence@gmail.com, io-uring@vger.kernel.org Cc: Fengnan Chang , Diangang Li References: <20251210085501.84261-1-changfengnan@bytedance.com> <20251210085501.84261-3-changfengnan@bytedance.com> <69f81ed8-2b4a-461f-90b8-0b9752140f8d@kernel.dk> <0661763c-4f56-4895-afd2-7346bb2452e4@gmail.com> <0654d130-665a-4b1a-b99b-bb80ca06353a@kernel.dk> <1acb251a-4c4a-479c-a51e-a8db9a6e0fa3@kernel.dk> <5ce7c227-3a03-4586-baa8-5bd6579500c7@gmail.com> <1d8a4c67-0c30-449e-a4e3-24363de0fcfa@kernel.dk> From: Fengnan Chang In-Reply-To: <1d8a4c67-0c30-449e-a4e3-24363de0fcfa@kernel.dk> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit 在 2025/12/12 09:53, Jens Axboe 写道: > On 12/11/25 6:41 PM, Fengnan Chang wrote: >> Oh, we can't add nr_events == iob.nr_reqs check, if >> blk_mq_add_to_batch add failed, completed IO will not add into iob, >> iob.nr_reqs will be 0, this may cause io hang. > Indeed, won't work as-is. > > I do think we're probably making a bigger deal out of the full loop than > necessary. At least I'd be perfectly happy with just the current patch, > performance should be better there than we currently have it. Ideally > we'd have just one loop for polling and catching the completed items, > but that's a bit tricky with the batch completions. Yes, ideally one loop would be enough, but given that there are also multi_queue ctx, that doesn't seem to be possible. >