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b=q84m+u7F9OyKhYoEEUc4C9Ew/QoiuZLPTbqwk/qnqW5tIwrU6Gj2+VRJqRsGG3v9F 6vpaYhZ6wGUUdvrcyV4OpvHA5bLUIyECCVmBHkf0xAOqIi+h+dDd0Bvzd90GIAXl5O IxZtDm0koUYaX0s/DkAmB2a1ObH5N/SrJFkEmv2Zvqw+hogYE/j+h2DXi7kyqCv7+H SnasqQphKIfPMvHfBDsFnSlnbAcahFpOBSI5VYphM0BINXwR/s3otJJYtE+1zuZSbk DXajYNIEnH9qTZWgpE4jhnefZ1sFeiHhbA9mFRCqMRej4rsQ1JpsrRLem/PYnU7ztu RaxM+cl65AfcQ== Date: Mon, 11 May 2026 15:06:19 +0300 From: Mike Rapoport To: Pratyush Yadav Cc: Pasha Tatashin , Alexander Graf , Muchun Song , Oscar Salvador , David Hildenbrand , Andrew Morton , Jason Miu , kexec@lists.infradead.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 09/12] memblock: introduce MEMBLOCK_KHO_SCRATCH_EXT Message-ID: References: <20260429133928.850721-1-pratyush@kernel.org> <20260429133928.850721-10-pratyush@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260429133928.850721-10-pratyush@kernel.org> X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: 25FAD4000B X-Stat-Signature: wzsmdbjdxgsdzysda5g1bze4nc48fa6c X-Rspam-User: X-HE-Tag: 1778501186-434353 X-HE-Meta: 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 gsmWXa47 e78vvON3v6KWARGXMZcQZOHTtHgrK+XXU6DTB2toZI6TIqh7ucrEcFhhYPCJ6Cjz+KPdgCH8Qfv1SxS/+ElNJWgUC5ATuUDsQXAAiwrxpKzDWhjNPQKDoR89qJ34HuwluFDaO0HaDV14ZC5dBAt8WNFqq75l4+9qVWU2jbLJqbeevbxQfAzsgAPfXYFHriv6IZbab+C68JzKArVk1I6/44szwNWQjnI8gk45Mpgef0y5mqT1z1GkjVBuFIITy6WGMrhE03q4PSO/A4RWS44cT8zkAmFePrlekQE6l1qp+2kmKmVzH4w8VZ6o3A8HgBZvHKIwI Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Wed, Apr 29, 2026 at 03:39:11PM +0200, Pratyush Yadav wrote: > From: "Pratyush Yadav (Google)" > > In the upcoming commits, the KHO will learn how to discover free blocks > of memory by walking the KHO radix tree. It will then mark those regions > as scratch to allow memory allocation in case scratch runs low. > > To differentiate the extended scratch areas from the main scratch areas, > introduce MEMBLOCK_KHO_SCRATCH_EXT. Use it when choosing memblock flags > for allocations during scratch-only. Teach should_skip_region() to check > for both flags before deciding if the region should be skipped. Why there's a need to differentiate SCRATCH and SCRATCH_EXT? SCRATCH (I still hate the name) means "memory memblock can safely use for the allocations". Initially this memory comes from the reservations in the first kernel, but if the second kernel can find more memory to extend it, why that additional memory should be treated differently? > Signed-off-by: Pratyush Yadav (Google) > --- > > Notes: > Checkpatch complains about no space after MEMBLOCK_KHO_SCRATCH_EXT in > the declaration, but doing so makes it nicely align with all the other > numbers. Mike, if you'd like I can add some whitespace. > > include/linux/memblock.h | 10 ++++++++++ > mm/memblock.c | 41 ++++++++++++++++++++++++++++++++++------ > 2 files changed, 45 insertions(+), 6 deletions(-) -- Sincerely yours, Mike.