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bh=UZzVY1rE4nuBeeTGJE+eDzU+/KFUPmhj+EbPbIqSZ4c=; b=e8+lqrCeUGLoeWHdMU2NT7TaFTqF+HMvYcUIDjJsltURgi0xQ/bx7qGFNQsEJYhQHMZsNe nMoOe/X4Lct1Kp4ZiNdvtgX///gTTodyn0euqKyxAR7nCtXXLqUkxJ4S6LcCfYb5MPWsbE Rhgy7btRp3nuFVbDEv4hzdAXPkCO/cP1DErzN/0zPuDj1jQMe2i570+hF9/d34b6dBh1tH yNSN17DLBKPXBt9MtVGwcWkbRDh8qYbWXR5/lkabo3HBYOUrAbkaXGgi6calsgTdR9vUW1 y4NXoSKSDxK0oZOw1bVwbG+TOCepPI0Xw5TwgT8KYbcGt0kuAYfnQojkef5EPg== Date: Fri, 23 Feb 2024 17:41:46 +0100 From: "Pankaj Raghav (Samsung)" To: Hannes Reinecke Cc: lsf-pc@lists.linuxfoundation.org, linux-mm@kvack.org, linux-block@vger.kernel.org, linux-scsi@vger.kernel.org, "linux-nvme@lists.infradead.org" , mcgrof@kernel.org, p.raghav@samsung.com Subject: Re: [LSF/MM/BPF TOPIC] Large block for I/O Message-ID: <43yvte5buxg4jv7nlguiz5eu5l26lkzz6cpa4snnvjqokbyg7i@42s52upzhrdi> References: <7970ad75-ca6a-34b9-43ea-c6f67fe6eae6@iogearbox.net> <4343d07b-b1b2-d43b-c201-a48e89145e5c@iogearbox.net> <03ebbc5f-2ff5-4f3c-8c5b-544413c55257@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <03ebbc5f-2ff5-4f3c-8c5b-544413c55257@suse.de> X-Rspam-User: X-Rspamd-Server: rspam12 X-Rspamd-Queue-Id: AA7FC100008 X-Stat-Signature: abp89fug1zr1qor7cknyizjoted6xjmk X-HE-Tag: 1708706514-877000 X-HE-Meta: U2FsdGVkX18wmrZNFjOcXk0x8i6JLNkbs3s5iYm25Ht8f20qyURy8Z22OmAOofA3ZbXrWuVeG+9vZbV2iAX2v2QAquXYCu0B29Fdu4f7bd79wVg8jsQlejAqa7z7GLMbiqUQ4rLrP5KhkDgnLsdHhj9pw6hXMojqaHnaAh6l8y+OOiB9xHAxFuSD4FMiR7v4pkYIluv0U26+OsIDWBLVc2+HrHEjCZ9bSmiVzOnlgjgHTpZAdudP39pIbPLkwA0kH63ZdhHy+pNHyxYScHIlmqt798oQ/EHdVWmfgic78wAJdRVp3jml3UYLDzlSNUmykTuKyCf/shaOeOz8W5Iw0kWZqLtoJx0aKXy0Qi3r1BRpOR2eFxjIczpj3hGCev7IRoMazd1fL6o7MvjJ+s7/KUJOnDyADgPWLsX4qIRquMkmUR1nO1HuxfxUb39M4fWUBoWKb7mV2UJGQ2PVjAl393IJAYoBLHa/81IjU7S10ZX/qVDux+vN6/W+6gHq+Ht79wwwPhjHKxBV9M7I/jp29urN2xkhJbFA/10UEDG6biHFTkuehn/KuLi2svJoAPjC63FUWlixTARvywnAlQftROKQUgyNPlU0T2h2vniO6W1X6td6UogZIkzk4n+dHS6TRYTiw0OyCwy87bNR0o/mBHMg/YA/zHk1MoYmGDiGBYCWBtMwXJE7JUxuByjOPSLUaXBzLID3eY0vIFzNKHiLh2LgCEVkISilE7pQ1On1yq3Pt1DX7cy94ygUnrCNaWPthZpk/6xgvqN71y9+F+vYgtMSEzV89ga29eeoNoS/x2H8EeFXv7k61SzvngTsgg5KrldPPWbuhsTJW9hJHfZ2DvXtHQyuGpsOCJGjbz2vuLB/AM5Zm4uniw9gk4DP2FaQTjbNnMQrR1HP2A8Ru/PgyNGtzJ19ur+IMisw76Hed9wZHEP7zMnhXvkTShGxBOuYg1xQNqSvv5Ne+O13BEp ZW+Y+PcM C7FSHYmxKAEI0lUydlyDPA8/LsLrk2mqrKc/S9FCziNBiV0uxc7E6uIaf15C9ZNYyoYCqfFQ1VmJ/8GiAcTXjvYOavuMFK440h77rOY5PzVpflaVm8rHgEm2VWuyMibhog4aE5B0cAJ13cUC7uNpEbskmWrbMkOMbw84dV8RAl/H9EhFI+1pkzVvJXtR/uTC6Ftrl9rNX7pdlz0vHiuLbvS3mdT26pL2K/CL5HzmivHWOuvUesmdaPAqkTp1fCskypBQM3PQ3u48mr4KcsWkBsRZoG6iME3+MmlS3pIzdzV2fCqWKcCegxao0K0LIZVnApLYTUKG22InqlUQ= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000068, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Wed, Dec 20, 2023 at 04:03:43PM +0100, Hannes Reinecke wrote: > Hi all, > > I would like to discuss > > Large blocks for I/O > > Since the presentation last year there has been quite some developments > and improvements in some areas, but at the same time a lack of progress > in other areas. > In this presentation/discussion I would like to highlight the current > state of affairs, existing pain points, and future directions of > development. > It might be an idea to co-locate it with the MM folks as we do have > quite some overlap with page-cache improvements and hugepage handling. I am interested in attending this session. As we are getting closer to having LBS in XFS[1], we could then have the LBS support for block devices for free if we use the iomap to interact with the block cache (!CONFIG_BUFFER_HEAD). So one of the focus points for this discussion could be on adding the LBS support to the buffer_head path for block devices and blockers (if any). Another important discussion point is testing. xfstests helped iron out bugs in page cache and iomap while adding the LBS support for XFS. If we add support to buffer_heads, then how are we going to stress test the changes? I doubt just blktests would be enough to test the changes in page cache and buffer_heads. [1] https://lore.kernel.org/linux-xfs/20240213093713.1753368-1-kernel@pankajraghav.com/ -- Pankaj