From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) (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 A22AE2673BA for ; Thu, 13 Mar 2025 12:26:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=90.155.50.34 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741868764; cv=none; b=R9DztV3ibWatLjs7L/dbtcXO8iZ1LJ3khPxRhZ/GSR2gD2jd6CKHi43VhavO0QZJ08X3pMtV2Z0iPRsVlQVG9VcLPg8vuRv38aoabvSV6ar1QW8mQfoyamK3TL1I7TpB43wM5sUjE8t0ou5IwNiW2+FceJSNlxqtlVSgddEdYVo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741868764; c=relaxed/simple; bh=TQM9aeAbGb6lPiwXrEfPpKe6hBYFrT+PLjVC5oJ7W6E=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=RMXmIgWkcEMrwC3SJqBssN0WieC8Q2UsD2RV6IB3no8pCTbo4/hYgGTFehoAA5ljrvTeRbxq+QVm7oxdc8mgtlMFIHp7bT0i3W8ngshh2BSvjGTw3OMEyBY5lBC6yA8S1goiogPsk1AUExcOT3EQjOvIu4Ix8AmXvyDF8pc4ayk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=sVpWpDp5; arc=none smtp.client-ip=90.155.50.34 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="sVpWpDp5" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=oUpCiEkkkXv8qjmMPM4PUHGiUlrQKPQ0xjfE1GNAcL4=; b=sVpWpDp5VfkvaKkumqZF0kF8ek N6iVPsAHPAjgEdL04cj/DenOsk9rXPpILf37hwGdsKmFPZ82RkswOTir4jT0sACy5fxv4erjo284N 5h1kIYAc/p83ZsDKIqZe6/MUQApWO/R6Gs2h+5xRynztT1HSX+bqG+yTpjGTdervg2aKr6lSya8Kz hMQKxzeDoQg1aOWKzS+2Do2whRRpfixkoyeX2E2TJi5QJDPQ/oyn7vV6yBtggecmLyVv7odmLm7iy NWncyHtbgZ1bfwT6JffbwE04fzgMHDip8QTHZjBVfhiQeRzaHiyq4XF6WNdjmohHA8a6T1dDHEIvu zogP2oyQ==; Received: from willy by casper.infradead.org with local (Exim 4.98 #2 (Red Hat Linux)) id 1tshdH-0000000GDiR-0ejo; Thu, 13 Mar 2025 12:25:51 +0000 Date: Thu, 13 Mar 2025 12:25:50 +0000 From: Matthew Wilcox To: Herbert Xu Cc: linux-mm@kvack.org, Andrew Morton , Linux Kernel Mailing List , Christoph Hellwig , Zi Yan , Eric Biggers Subject: Re: [PATCH] mm: Move nth_page from folio_page into folio_next Message-ID: References: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Thu, Mar 13, 2025 at 12:40:34PM +0800, Herbert Xu wrote: > Discontiguous memory may require the use of nth_page instead of adding > to struct page arithmetically. However, discontiguous memory cannot > exist within a single folio. That isn't true. HugeTLB can construct a folio which crosses a contiguity boundary.