From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.9 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8E8C2C4741F for ; Wed, 4 Nov 2020 19:11:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 05BB1206D4 for ; Wed, 4 Nov 2020 19:11:17 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="NPG7qtUM" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730697AbgKDTLP (ORCPT ); Wed, 4 Nov 2020 14:11:15 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33592 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730505AbgKDTLO (ORCPT ); Wed, 4 Nov 2020 14:11:14 -0500 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 45A75C0613D4; Wed, 4 Nov 2020 11:11:14 -0800 (PST) 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=tL7XJijJaQjwTxWIpvyG0Z04LWofXKLSq0OiO7y+/KA=; b=NPG7qtUMlTa1nWx/dCiRtjrzAm uvzvL11rz1BkIY9c3sFCvwoAyhFSgnKDU6wYsP4jtzxXvHAHRcThjSR0QdGNZxURF5/Mnv6jv9A6j rZFIt3dys+tq3zDRu9IWpCB3VIPl4XqTlerWjLqykkYXKSq/1Iwb8njh4S3bKbHlIkuajXoZqXzXN lxPIETsCwT6aD/XHXbgyolg4DLvnRF59IVxRmDyfMyBCPMkU+qPasSUP83dld7ZXkjefdZWM+3dht MLZq0SxVmAJ5A0wpbvSVKCeIY22GHZrGMo4GZpbiQ+DFONzc3IP3h9R5ozJwnoOhH5w3slCDvbMWC NV+PGvFQ==; Received: from hch by casper.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1kaOBQ-00074n-Ui; Wed, 04 Nov 2020 19:11:00 +0000 Date: Wed, 4 Nov 2020 19:11:00 +0000 From: Christoph Hellwig To: Jason Gunthorpe Cc: John Hubbard , Christoph Hellwig , Daniel Vetter , J??r??me Glisse , linux-samsung-soc , Jan Kara , Pawel Osciak , KVM list , Mauro Carvalho Chehab , LKML , DRI Development , Tomasz Figa , Linux MM , Kyungmin Park , Daniel Vetter , Andrew Morton , Marek Szyprowski , Dan Williams , Linux ARM , "open list:DMA BUFFER SHARING FRAMEWORK" , Thomas Bogendoerfer Subject: Re: [PATCH v5 05/15] mm/frame-vector: Use FOLL_LONGTERM Message-ID: <20201104191100.GA25011@infradead.org> References: <20201104140023.GQ36674@ziepe.ca> <20201104162125.GA13007@infradead.org> <20201104163758.GA17425@infradead.org> <20201104164119.GA18218@infradead.org> <20201104181708.GU36674@ziepe.ca> <20201104190214.GW36674@ziepe.ca> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201104190214.GW36674@ziepe.ca> L: linux-mips@vger.kernel.org X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org. See http://www.infradead.org/rpr.html Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Wed, Nov 04, 2020 at 03:02:14PM -0400, Jason Gunthorpe wrote: > I saw that once and I really couldn't make sense of it.. > What use is having futex's that only work on THP pages? Confused > > CH said there was no case of HAVE_FAST_GUP !ARCH_HAS_PTE_SPECIAL, is > one hidden someplace then? ARCH_HAS_PTE_SPECIAL is selected by: arc arm (if LPAE) arm64 mips (if !(32BIT && CPU_HAS_RIXI)) powerpc riscv s390 sh sparc (if SPARC64) x86 HAVE_FAST_GUP is supported by: arm (if LPAE) arm64 mips powerpc s390 sh x86 so mips would be a candidate. But I think only in theory, as the options selecting CPU_HAS_RIXI do not select CPU_SUPPORTS_HUGEPAGES. Adding the mips maintainer to double check my logic.