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[89.138.77.243]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-49cf7703cefsm251955455e9.5.2026.09.05.17.09.14 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sat, 05 Sep 2026 17:09:15 -0700 (PDT) Message-ID: Date: Sun, 6 Sep 2026 03:09:14 +0300 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 3/6] nvme: add per request retry timer To: Christoph Hellwig Cc: linux-nvme@lists.infradead.org, Keith Busch , Chaitanya Kulkarni , Daniel Wagner , Shinichiro Kawasaki , Hannes Reinecke References: <20260823084903.193188-1-sagi@grimberg.me> <20260823084903.193188-4-sagi@grimberg.me> <20260902134156.GC21649@lst.de> Content-Language: en-US From: Sagi Grimberg In-Reply-To: <20260902134156.GC21649@lst.de> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260905_170917_950873_16A0E618 X-CRM114-Status: GOOD ( 11.49 ) X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org On 02/09/2026 16:41, Christoph Hellwig wrote: > On Sun, Aug 23, 2026 at 11:48:59AM +0300, Sagi Grimberg wrote: >> The existing command retry mechanism adds a request to retry >> to a retry list and modifies a request-queue (controller) wide >> dealyed queue timer. >> >> The issue is that the existing requests in this queue may wait >> for longer periods of time as more requests are completed with >> a retry crd level. >> >> Instead, add a per-request timer that will allow different >> requests retry in a way that is independent of other requests. > This blows every nvme_request. I think we'd only need a per-CRD > level retry list and timer, can't we do that instead? I can't see how, because we'd be modifying the timer potentially indefinitely while requests are pending.... I understand that this bloats the nvme_request, however this is not accessed in the hot path.