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charset=us-ascii Content-Disposition: inline In-Reply-To: <20251116014721.1561456-2-jiaqiyan@google.com> X-Rspamd-Queue-Id: 1AD23A0006 X-Rspamd-Server: rspam07 X-Stat-Signature: otoiyxeu86s6xqwezkqdy1rr6hqukkxw X-Rspam-User: X-HE-Tag: 1763293887-525848 X-HE-Meta: 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 R/3dm84y p6F05/CpaTZ0S4SOPtDlMsCNzrT9ruxmohHKmjBv2rzM8qqvbUQAg6HOFvk2atAgJjdcrdWWvXWWXKM/VHqYyxBHRvc8JKhsOJu4TocqYwaqHuUZy89a1ABmi2Uj74qGmBnglzUy3ZoD1ox2phSHyAJKKWFuF/j956Wfg8Tbvr7sNwSFEM95zZHZuLKnF8sEixBq8d6iWXuKN4q0W+iS61QrBuF4HRfTNYZkol1SAGnedQwsne06QKJmt+zikJawZX78Zcu0RHxlWmmt6puaEj4gHtNXn6bTyPozEEGvYZRDp8osWHX8Yz64a4OFTQRpExDtqKq3FnFl3MndDz1VFYBNnLT2pAWS9XN+AvfRl3fGV52JO6H3cl9sv8g== 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 Sun, Nov 16, 2025 at 01:47:20AM +0000, Jiaqi Yan wrote: > Introduce uniform_split_unmapped_folio_to_zero_order, a wrapper > to the existing __split_unmapped_folio. Caller can use it to > uniformly split an unmapped high-order folio into 0-order folios. Please don't make this function exist. I appreciate what you're trying to do, but let's try to do it differently? When we have struct folio separately allocated from struct page, splitting a folio will mean allocating new struct folios for every new folio created. I anticipate an order-0 folio will be about 80 or 96 bytes. So if we create 512 * 512 folios in a single go, that'll be an allocation of 20MB. This is why I asked Zi Yan to create the asymmetrical folio split, so we only end up creating log() of this. In the case of a single hwpoison page in an order-18 hugetlb, that'd be 19 allocations totallying 1520 bytes. But since we're only doing this on free, we won't need to do folio allocations at all; we'll just be able to release the good pages to the page allocator and sequester the hwpoison pages.