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[221.255.142.61]) by smtp.gmail.com with ESMTPSA id a92af1059eb24-11f2e1bb3b4sm12870968c88.4.2025.12.11.17.53.06 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 11 Dec 2025 17:53:07 -0800 (PST) Message-ID: <1d8a4c67-0c30-449e-a4e3-24363de0fcfa@kernel.dk> Date: Thu, 11 Dec 2025 18:53:05 -0700 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: Fengnan Chang , 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> Content-Language: en-US From: Jens Axboe In-Reply-To: <5ce7c227-3a03-4586-baa8-5bd6579500c7@gmail.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit 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. -- Jens Axboe