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[65.112.8.52]) by smtp.gmail.com with ESMTPSA id 6a1803df08f44-6f542623ef8sm17522416d6.19.2025.05.07.11.29.33 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 07 May 2025 11:29:33 -0700 (PDT) Date: Wed, 7 May 2025 14:29:31 -0400 From: Alan Stern To: Jake Rice Cc: linux-usb@vger.kernel.org, gregkh@linuxfoundation.org, usb-storage@lists.one-eyed-alien.net, linux-kernel@vger.kernel.org Subject: Re: [RFC PATCH] usb: storage: Add blockbuffer ptr to info struct of sddr09 driver Message-ID: References: <20250506191531.3326-1-jake@jakerice.dev> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250506191531.3326-1-jake@jakerice.dev> On Tue, May 06, 2025 at 03:15:31PM -0400, Jake Rice wrote: > Hi all, > > This patch updates the sddr09 driver to allocate a reusable block > buffer. Unfortunately, I don't have access to the SDDR-00 hardware > (which I know is pretty ancient), so I'm requesting testing from anyone who does. > Please let me now if the patch causes any issues or improves performance. > > Best, > Jake > > --- > Currently, upon every write the block buffer is allocated and freed which is > computationally expensive. With this implementation, a buffer pointer > is added as a member to the info struct and allocated when the card > information is read. The buffer is freed during desconstruction if > necessary. This isn't a high-priority sort of thing. SDDR-09 is indeed very old and likely quite slow (by comparison with current hardware); the time required for the memory allocations and deallocations probably doesn't have much effect on the overall I/O rate. Still, I guess it doesn't hurt to do this. However, I don't have time to review the patch properly right now, and I don't have the hardware to test it with. Alan Stern