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Howlett" , Mike Rapoport , Michal Hocko , Jason Gunthorpe , John Hubbard , Peter Xu , Matthew Wilcox , Usama Arif Date: Mon, 27 Jul 2026 20:37:19 -0400 In-Reply-To: <5490f8b1-d611-4e4d-bd8b-19c0e05698a3@kernel.org> References: <20260724222934.1463812-1-riel@surriel.com> <20260724222934.1463812-12-riel@surriel.com> <5490f8b1-d611-4e4d-bd8b-19c0e05698a3@kernel.org> Autocrypt: addr=riel@surriel.com; prefer-encrypt=mutual; keydata=mQENBFIt3aUBCADCK0LicyCYyMa0E1lodCDUBf6G+6C5UXKG1jEYwQu49cc/gUBTTk33A eo2hjn4JinVaPF3zfZprnKMEGGv4dHvEOCPWiNhlz5RtqH3SKJllq2dpeMS9RqbMvDA36rlJIIo47 Z/nl6IA8MDhSqyqdnTY8z7LnQHqq16jAqwo7Ll9qALXz4yG1ZdSCmo80VPetBZZPw7WMjo+1hByv/ lvdFnLfiQ52tayuuC1r9x2qZ/SYWd2M4p/f5CLmvG9UcnkbYFsKWz8bwOBWKg1PQcaYHLx06sHGdY dIDaeVvkIfMFwAprSo5EFU+aes2VB2ZjugOTbkkW2aPSWTRsBhPHhV6dABEBAAG0HlJpayB2YW4gU mllbCA8cmllbEByZWRoYXQuY29tPokBHwQwAQIACQUCW5LcVgIdIAAKCRDOed6ShMTeg05SB/986o gEgdq4byrtaBQKFg5LWfd8e+h+QzLOg/T8mSS3dJzFXe5JBOfvYg7Bj47xXi9I5sM+I9Lu9+1XVb/ r2rGJrU1DwA09TnmyFtK76bgMF0sBEh1ECILYNQTEIemzNFwOWLZZlEhZFRJsZyX+mtEp/WQIygHV WjwuP69VJw+fPQvLOGn4j8W9QXuvhha7u1QJ7mYx4dLGHrZlHdwDsqpvWsW+3rsIqs1BBe5/Itz9o 6y9gLNtQzwmSDioV8KhF85VmYInslhv5tUtMEppfdTLyX4SUKh8ftNIVmH9mXyRCZclSoa6IMd635 Jq1Pj2/Lp64tOzSvN5Y9zaiCc5FucXtB9SaWsgdmFuIFJpZWwgPHJpZWxAc3VycmllbC5jb20+iQE +BBMBAgAoBQJSLd2lAhsjBQkSzAMABgsJCAcDAgYVCAIJCgsEFgIDAQIeAQIXgAAKCRDOed6ShMTe g4PpB/0ZivKYFt0LaB22ssWUrBoeNWCP1NY/lkq2QbPhR3agLB7ZXI97PF2z/5QD9Fuy/FD/jddPx KRTvFCtHcEzTOcFjBmf52uqgt3U40H9GM++0IM0yHusd9EzlaWsbp09vsAV2DwdqS69x9RPbvE/Ne fO5subhocH76okcF/aQiQ+oj2j6LJZGBJBVigOHg+4zyzdDgKM+jp0bvDI51KQ4XfxV593OhvkS3z 3FPx0CE7l62WhWrieHyBblqvkTYgJ6dq4bsYpqxxGJOkQ47WpEUx6onH+rImWmPJbSYGhwBzTo0Mm G1Nb1qGPG+mTrSmJjDRxrwf1zjmYqQreWVSFEt26tBpSaWsgdmFuIFJpZWwgPHJpZWxAZmIuY29tP okBPgQTAQIAKAUCW5LbiAIbIwUJEswDAAYLCQgHAwIGFQgCCQoLBBYCAwECHgECF4AACgkQznneko TE3oOUEQgAsrGxjTC1bGtZyuvyQPcXclap11Ogib6rQywGYu6/Mnkbd6hbyY3wpdyQii/cas2S44N cQj8HkGv91JLVE24/Wt0gITPCH3rLVJJDGQxprHTVDs1t1RAbsbp0XTksZPCNWDGYIBo2aHDwErhI omYQ0Xluo1WBtH/UmHgirHvclsou1Ks9jyTxiPyUKRfae7GNOFiX99+ZlB27P3t8CjtSO831Ij0Ip QrfooZ21YVlUKw0Wy6Ll8EyefyrEYSh8KTm8dQj4O7xxvdg865TLeLpho5PwDRF+/mR3qi8CdGbkE c4pYZQO8UDXUN4S+pe0aTeTqlYw8rRHWF9TnvtpcNzZw== Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.56.2 (3.56.2-2.fc42) MIME-Version: 1.0 X-Rspam-User: X-Rspamd-Server: rspam09 X-Rspamd-Queue-Id: 087DC40003 X-Stat-Signature: iopcbe53cjx6yrbnj6j84qy1eaaqfdi8 X-HE-Tag: 1785199148-738370 X-HE-Meta: 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 Z3iynw2X ag2hXO+8cGh/e1tytxV0j+5s8I+sYBsc3bEn6jh0Xdco4K6H7c6VNOv7NPQcDNPYnCafUawRA6cIUMuYYUBJPS08p+gy9hyzui10aMyjTXPDP9czR3Q9XWhpVlsytJLX+mx1iqs/zF4wuR5SwvycFpC+3SAD9uNwE6s0oJiqnRGKZN4ULFjQyDjfRaCMe45gX2xir7t1aziV/dT0m/GzW4cCiRq7+5SSrjCFivDL3jiIg9W75L2P5uOo6zB+786gA9IGu6gZ+Rbwge7eImzklunLTx/qhsmmyR+Uv13DI1/tYpgaUwLe42Lx1y41j3Is3LYo7uZC6fqIEYcs= Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Mon, 2026-07-27 at 15:54 +0200, David Hildenbrand (Arm) wrote: > On 7/25/26 00:29, Rik van Riel wrote: > >=20 > > =C2=A0 gup_test -L -m 256 -n 65536 -r 16 -t > > =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2= =A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 befor= e=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 after > > =C2=A0 64 kB mTHP=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0= =C2=A0=C2=A0 3140 us=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 412 us=C2=A0=C2=A0 (7.6x= ) > > =C2=A0 2 MB THP (control)=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 78 us=C2=A0=C2= =A0=C2=A0=C2=A0=C2=A0=C2=A0 76 us > > =C2=A0 4 kB base (control)=C2=A0=C2=A0 3010 us=C2=A0=C2=A0=C2=A0=C2=A0 = 3042 us > >=20 > > The PMD-mapped 2 MB THP already returns the whole mapping in one > > step, so > > it stays fast and unchanged. The 4 kB baseline shows the per-page > > walk cost > > that the 64 kB case paid before this change; only the PTE-mapped > > large > > folio case improves. > >=20 > > Assisted-by: Claude:claude-opus-4.8 > > Signed-off-by: Rik van Riel >=20 > Why is this patch part of this patch set? >=20 > This makes perfect sense independently, no? I'm happy to drop this for now. I think it would fit in better with another optimization to only take one refcount per continuously mapped extent of pages from the same folio. I can't really untangle it because it modifies some of the same code as other patches in the series, but I'm happy to save it for a follow-up. --=20 All Rights Reversed.