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b=h7KdYcYZ4TuJrTT9jdQuQQl1OLRj2Xne9zxcLYqOohZYz1j1dBAGVGbe7q3J1Bpdv v7jCIZsl8PHuZG5EpHnuXqatbF+AOqG4GSdNAN4Y+ikB5K7S/3k88KgcRHrTma5RtC YVyTej0OP9knbwCn5qxky/lVy9SQCIiEBEYCSkRY= Date: Thu, 27 Nov 2025 12:55:39 -0800 From: Andrew Morton To: Usama Arif Cc: rppt@kernel.org, kas@kernel.org, changyuanl@google.com, graf@amazon.com, leitao@debian.org, thevlad@meta.com, pratyush@kernel.org, dave.hansen@linux.intel.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, kernel-team@meta.com Subject: Re: [PATCH v2 2/2] mm/memblock: only mark/clear KHO scratch memory when needed Message-Id: <20251127125539.98b2f148c6225f1cb7c9d045@linux-foundation.org> In-Reply-To: <20251127203724.3177621-3-usamaarif642@gmail.com> References: <20251127203724.3177621-1-usamaarif642@gmail.com> <20251127203724.3177621-3-usamaarif642@gmail.com> X-Mailer: Sylpheed 3.8.0beta1 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: B6CA740008 X-Stat-Signature: 4sqt3wn36beg6qnsks945685c6wqa8m9 X-Rspam-User: X-HE-Tag: 1764276941-183868 X-HE-Meta: U2FsdGVkX1+axCrRV8W1PQ/gfenybNwL62XjspVoraj4c5EhOfrC2Mn3K23ilzxhhBKlKzbv+dMBLx5ayeJrtNUi2V/5+H7WE3+LyyJcn4LWaax810TbnideAISD6R/jRqXPanI1mQWjB33K5XcFZ8NFD1htMlfJwVCWlkNDt5vp4AdFBL6z5L8dvq2O210IMPozAYryRaJELSiFaIA3E/m9yz04Js41/stexDEpSxycmy3Rj4j3uzcc3L30h9pcUhp8IKx1f+RTTeQOABl1+gIi53isxGQu4KJnA/oGqMrXyVKlGK6oqrTmKr+6duOFuyxlv48QAcQJYeyA4ASPCqPIr2jNbFt96pcusNUjCn+PaRBROsxjhQHiT0pXZ0EabChirvCLslfawdhyOi2a4GNmby07pb8GxIj+mcC/qqX3/BNVqofBrHpgokwZFWXRWlqYb7Rcx3AFtJVWL1m/gfHBgAJIy2NynFvp1A7xPIb2Z4vsUCr6Rx6Wp7hu66sEEVsm+0s0Uhyh7D3vUIkNuwNuJrXKrqCGaqRt/j85DCIzZ7AerOJ13xdnrRIXzEc4HGhtAnkElz2sBUQZKS/PgH6kIsCag+2XW/wsgqFj0ME+dEailmMRPTTqBkoHAMe3XGrHRgMESPCN/5pqWlYcUq8XMHMQKZx4dElEeHgvAcGuEVeC0XQUTkFi+Ukiam4d9I3mRm+nMpvdhLTVix1P388WL4CCiLeHx2ejRrBtCvISHKgYd/b01bd+vHAWtKZ8EGDi3KK3RKSXvmxKpkj5EHS+4/RdDQ98ApsdA5Xgu2AxyPCiD9Xz5H8lVStO+U49o9KGg1dwNp1QnHWCfI9PUaA318ZeL/+BYhFJZX6R8Yy+GO3Smi4OF20H9eguvtLg8uhxgL8vCTYhAG+BIJz4sXYSswyHIepZ/dCyehW64+8GAsTwGvWsdtfdMECRD7AcL8J06y3yr1qOqe9TV65 i2KfBAdU KnXTyhRNt7kTdHQvVu5+FMwLu8DJYzAoP8DXWwjW1TsljVaL2e7neKGXcKTyNRLN1nVMHyvJAWxSXNmfW3vo1zWG+O1AX2aKX2rLGXUnGFdL2dIuC9ft8k43uSsvGxcF1OUbiALXNAt0JlRbX+gpgQf92ecqKCgVgE7Y7SZYwkvRj1ApWN25YIeRU7hq2esEfMg1tNDpjEeFr0ztPndYwYay0QJo0paw/pqPtfFqMjmsG2PmGwXn6yw3pMfTj6kzbdrYC2nIgQpQ/aEvwQf1EM+BavA== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, 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 Thu, 27 Nov 2025 20:33:20 +0000 Usama Arif wrote: > The scratch memory for kexec handover is used to bootstrap the > kexec'ed kernel. It is only needed when CONFIG_KEXEC_HANDOVER > is enabled and only if it is a KHO boot. Add checks to prevent > marking a KHO scratch region unless needed. What effect does this change have? Lessened memory consumption, presumably. Of what magnitude and for what time period?