From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from shelob.surriel.com (shelob.surriel.com [96.67.55.147]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0A3084AD4AE for ; Fri, 25 Sep 2026 19:00:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=96.67.55.147 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790362870; cv=none; b=GDzGx3AaXJrTA+vkcH9ddpxuBVMzvdmhRCL+UB7NK8YMqz4PunDnmbG2rctG5iZ99Uw/U/Vg+BdcHc0GXWAVeVss/hgISqEkCEqBve9U5EFhPxrM8yqeejIORwuYyxXC6mUWUt9c4OP95dr9qXKF5X7BIVL4a1OuWY3urA/KoXQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790362870; c=relaxed/simple; bh=cp3KpeoSWqR5DrpiHmEm+y4xxrxVLkmSxI1ryA+o7ns=; h=Message-ID:Subject:From:To:Cc:Date:In-Reply-To:References: Content-Type:MIME-Version; b=iFNTEwLNSWDHHwfJ6vqc0n/O1BcU+xj08QvIO1lwcKOJ4RIKI9N5cuw4QGWLW6/nupxmaTstBwu8W4fB8xdx/0SYG/9wtsOhDQ7vx5pWSue+seQMqgXoJiMzvQ4wx7JSJ8RtO9k5Q1yOX1ER6Wov1iOgQGwLPyaWm2OyiN9LFnQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=surriel.com; spf=pass smtp.mailfrom=surriel.com; dkim=pass (2048-bit key) header.d=surriel.com header.i=@surriel.com header.b=VA8kCMU2; arc=none smtp.client-ip=96.67.55.147 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=surriel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=surriel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=surriel.com header.i=@surriel.com header.b="VA8kCMU2" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=surriel.com ; s=mail; h=MIME-Version:Content-Transfer-Encoding:Content-Type:References: In-Reply-To:Date:Cc:To:From:Subject:Message-ID:Sender:Reply-To:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID; bh=cp3KpeoSWqR5DrpiHmEm+y4xxrxVLkmSxI1ryA+o7ns=; b=VA8kCM U2XQAteHMN1acW47NufAGdhZPD1ooxBi7kh9whJOeSyIr//j0lyhZd4fyKo0PaFB33k6oo9QZSM3O YSWXSGnfCUNu2DK5KPiuxFBAQ8dB/ZlgtyAkefIO95VDAuMJJtr+8p4xmwJPLOc4GeuDGr+FDwpct KWbh3wZ6yLbvsJkxtZVzfDjwPNHgS0V71410DaIMKmEmwuZ6Hvspb46rfa/sWWOkNCaMMdD6Qy3zx 8uC8EL1iseMq9VZK/iE4ro+hFDfpZtd4BhV/BeHGuBjxl32+a8jmB6IZaa7uDKd5yvKlERb6AL8ya 0odqnoUIWuulxh2CAbJssW3a3Irg==; Received: from [2601:18c:8100:a0e0:5a47:caff:fe78:8708] by shelob.surriel.com with esmtpsa (TLS1.3) tls TLS_AES_256_GCM_SHA384 (Exim 4.99.5) (envelope-from ) id 1xAB9I-00000006GnA-05It; Fri, 25 Sep 2026 18:59:56 +0000 Message-ID: Subject: Re: [PATCH] mm/vma: don't remove VMA from rmap if pgoff unchanged From: Rik van Riel To: "Lorenzo Stoakes (ARM)" , Andrew Morton , David Hildenbrand , "Liam R. 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) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 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.