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[173.79.56.208]) by smtp.gmail.com with ESMTPSA id 6a1803df08f44-6e65d7a4430sm89493726d6.65.2025.02.20.11.35.57 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 20 Feb 2025 11:35:57 -0800 (PST) Date: Thu, 20 Feb 2025 14:35:55 -0500 From: Gregory Price To: David Hildenbrand Cc: Yang Shi , lsf-pc@lists.linux-foundation.org, linux-mm@kvack.org, linux-cxl@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: CXL Boot to Bash - Section 3: Memory (block) Hotplug Message-ID: References: <1b4c6442-a2b0-4290-8b89-c7b82a66d358@redhat.com> <4ae838ee-b079-408e-8799-e9530ca50417@redhat.com> 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: <4ae838ee-b079-408e-8799-e9530ca50417@redhat.com> On Thu, Feb 20, 2025 at 08:26:21PM +0100, David Hildenbrand wrote: > On 20.02.25 19:43, Gregory Price wrote: > > There were ideas in how to optimize that (e.g., requiring a new sysfs > interface to expose variable-sized blocks), if anybody is interested, please > reach out. > Multiple block sizes would allow managing the misaligned issues I discussed earlier as well (where a memory region is not aligned to the arch-preferred block size). At least in that scenario, the misaligned regions could be brought online as minimal block size (256MB) while the aligned portions could be brought online in larger (2GB) chunks. Do you think this would this require a lot of churn to enable? Last I dug through hotplug, it seemed to assume block sizes would be uniform. I was hesitant to start ripping through it. ~Gregory