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Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Harry Yoo , Jann Horn , Lance Yang , Pedro Falcato Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Pan Deng Date: Fri, 25 Sep 2026 14:59:54 -0400 In-Reply-To: <20260925-speed-up-inplace-rmap-v1-1-babc48ce7c83@kernel.org> References: <20260925-speed-up-inplace-rmap-v1-1-babc48ce7c83@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 3.60.2 (3.60.2-1.fc44) MIME-Version: 1.0 X-Rspam-User: X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: BD79C180007 X-Stat-Signature: mnrz5gsd19zncox8n8jcwqw6a3dwrr4y X-HE-Tag: 1790362847-387332 X-HE-Meta: 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 qgcsBDiE CqsX4gVKnc2BuwILyFHGw56yiv1A8mcoJye7eOCRkf92s1tLshpheioyBVXIDH/ErGCj4TYq0Lv9zNpRlicvAUX7vSzLxBzo5jlbjwLYcvcHhXWG7bJ1yi2iY/9UMkqi5iMqCSCY1ZPgl/apWsEOjxWBRvWXGh4tJYVji/CrHo5q2VMjY2H8q/VeTXGZNL00qMxGdFomWUkhFmpWRxAhWPJsP6M9kzxld2jFjVJxr06hoaj1fQCf3S35eYcJo7bKi5PX4FLT9xWj0kYEpxdIZbusOY0P4wxVsFvIhLN8SOrd9fVo2CdnSGzUQdDCLS2RvxhSY6pNmq+GAiA4nLD/2SVPpjWPiy55M6IrWxFNtx0gIDvQHIpI5UPMzWZL8gzt6260j Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Fri, 2026-09-25 at 19:32 +0100, Lorenzo Stoakes (ARM) wrote: >=20 > When performing a VMA shrink or a split where the VMA is the lower > one, the > page offset cannot change, so set the flags unconditionally in these > cases. >=20 > When merging VMAs the page offset is unchanged only in some cases, so > update init_multi_vma_prep() to set the flags only if the page > offsets > remain the same. >=20 > These changes ultimately result in less rmap lock contention. >=20 > Reported-by: Pan Deng > Closes: > https://lore.kernel.org/linux-mm/20260924054301.2330822-1-pan.deng@intel.= com/ > Signed-off-by: Lorenzo Stoakes Nice optimization. Reviewed-by: Rik van Riel --=20 All Rights Reversed.