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 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 99FDAC3DA6E for ; Mon, 8 Jan 2024 07:28:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=F7UHq5k/KEl2wzDAasl4jY7lVgjlAZ1wcwwPd4JTbDY=; b=yWwy4AFFSKB0XL b2e5/rcglq+1YNcSl5CQvrVK7d8YiHUT7t+lGFJAnu+UNYbLOFK6xH1Ky4H7z0YrqXFLFU83nBnJe zajrwYwytajUGZRY/3iaIEGRPWCpuwm+83LWCvLbxeO8Cc9Y4sJa6hUv0bCg7SeVxJC14gL/TKgk4 G1PM/RXS1GYdj3F9YeDe8uBAwLxeVNRZQx7HWwXO3BauISxGmTX5b6mWwJAtRerIOgoUcc6qhQrpF RR8z3IKosM5QnYEXY1Z36Umtv4XJxghpMAm3eGfV+/fSTsK0XnnOWwP++ikd3BrdAMVAdtLLhn6T+ iM/FaInPFjUWD3A18coA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1rMk2s-004B4S-2K; Mon, 08 Jan 2024 07:27:38 +0000 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1rMk2p-004B35-2Y for linux-arm-kernel@lists.infradead.org; Mon, 08 Jan 2024 07:27:37 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1704698851; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=++HIVa+fUHc7mVxMPbgRezSHjTqa6qZR6U7zKUbz7Hc=; b=ICVyQ4vvWaweiGQQeg9cd9GTYQ0qgjJnb+zxvLHcmc+5VCVvmN80VpdO4hYiPbEfvFyjK3 1r7mA272zVQtL4jQGMGciDza4oL1C7XLIwL97P48LpnyQN+8JA5TXTywvw7TZqIqYxVh7M 3HT5rjWwuYN3xsybTA1XKx8sJez1VTU= Received: from mail-pj1-f72.google.com (mail-pj1-f72.google.com [209.85.216.72]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-298-LCYsCTnHPjOu4DUEtInQjQ-1; Mon, 08 Jan 2024 02:27:30 -0500 X-MC-Unique: LCYsCTnHPjOu4DUEtInQjQ-1 Received: by mail-pj1-f72.google.com with SMTP id 98e67ed59e1d1-28cfa4a37c2so746191a91.0 for ; Sun, 07 Jan 2024 23:27:29 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1704698849; x=1705303649; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=++HIVa+fUHc7mVxMPbgRezSHjTqa6qZR6U7zKUbz7Hc=; b=vdES0ZLek80zBuZJX90BkHE3qd3HH17C14/v0OTDpGzcz+/Y4CVLAfThksfeBmLVcn 7x09xnFp2pJ/1FWS/a095LpGTnbo7VWuJqxbv+xWiUiYWv8xEP668Sl1I982pplxDd8r vNiAByt0SxhXLifeuGUQugVvBwWtioIR/gXL20vZMeT/A7AVkiH/VoY3VpzyNy4FeOgT XKTT8pqPxOyS95oN1lxu575ZPFTUuXtlzOL8ekVcBdn803mSF6nscuclyuSNvVCMxEcL gP6pKaISpXTtWadb7GM3gsUomW/el/DJj1bOB0dqzlqISqf9Q/+M7HSZUm6EiZ+Q4leP nrLQ== X-Gm-Message-State: AOJu0YzSew1mYQu/XE+jEdrJMv0rALSl8p5j4eJ0vVZffPMNeo1jAVTJ Fz18MgE7x5HhvY7Z9Xqxk8lIgT0cRik6mEV6q2rhFv+6m3eX8ouYvf7gbZPaXkF02yz/eou/wbQ wMFLkKTkQXAd9z92I493MTg0/7h44RQtNM3ZBpdBGD7g= X-Received: by 2002:a05:6a20:3cab:b0:199:c866:1d46 with SMTP id b43-20020a056a203cab00b00199c8661d46mr931053pzj.6.1704698848992; Sun, 07 Jan 2024 23:27:28 -0800 (PST) X-Google-Smtp-Source: AGHT+IHCAavyxZcZwU5CLY8vR5nixlH4bDIz/ZGJUz9tbspcbUqeK+w5R+Hs85r/f/cHobBdBUdCsQ== X-Received: by 2002:a05:6a20:3cab:b0:199:c866:1d46 with SMTP id b43-20020a056a203cab00b00199c8661d46mr931031pzj.6.1704698848614; Sun, 07 Jan 2024 23:27:28 -0800 (PST) Received: from x1n ([43.228.180.230]) by smtp.gmail.com with ESMTPSA id d5-20020a17090a8d8500b0028c2de909e4sm5617976pjo.50.2024.01.07.23.27.22 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 07 Jan 2024 23:27:28 -0800 (PST) Date: Mon, 8 Jan 2024 15:27:17 +0800 From: Peter Xu To: Christophe Leroy Cc: "linux-mm@kvack.org" , "linux-kernel@vger.kernel.org" , James Houghton , David Hildenbrand , "Kirill A . Shutemov" , Yang Shi , "linux-riscv@lists.infradead.org" , Andrew Morton , "Aneesh Kumar K . V" , Rik van Riel , Andrea Arcangeli , Axel Rasmussen , Mike Rapoport , John Hubbard , Vlastimil Babka , Michael Ellerman , Andrew Jones , "linuxppc-dev@lists.ozlabs.org" , Mike Kravetz , Muchun Song , "linux-arm-kernel@lists.infradead.org" , Jason Gunthorpe , Christoph Hellwig , Lorenzo Stoakes , Matthew Wilcox Subject: Re: [PATCH v2 00/13] mm/gup: Unify hugetlb, part 2 Message-ID: References: <20240103091423.400294-1-peterx@redhat.com> <591c59d6-dedb-4399-8a6f-c574fd2ad9cc@csgroup.eu> MIME-Version: 1.0 In-Reply-To: <591c59d6-dedb-4399-8a6f-c574fd2ad9cc@csgroup.eu> X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Disposition: inline X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240107_232735_922193_D94ADF6E X-CRM114-Status: GOOD ( 21.41 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hi, Christophe, On Wed, Jan 03, 2024 at 11:14:54AM +0000, Christophe Leroy wrote: > > Test Done > > ========= > > > > This v1 went through the normal GUP smoke tests over different memory > > types on archs (using VM instances): x86_64, aarch64, ppc64le. For > > aarch64, tested over 64KB cont_pte huge pages. For ppc64le, tested over > > 16MB hugepd entries (Power8 hash MMU on 4K base page size). > > > > Can you tell how you test ? > > I'm willing to test this series on powerpc 8xx (PPC32). My apologies, for some reason I totally overlooked this email.. I only tested using run_vmtests.sh, with: $ bash ./run_vmtests.sh -t gup_test -a It should cover pretty much lots of tests of GUP using gup_test program. I think the ones that matters here is "-H" over either "-U/-b". For ppc8xx, even though kernel mapping uses hugepd, I don't expect anything should change before/after this series, because the code that I touched (slow gup only) only affects user pages, so it shouldn't change anything over kernel mappings. Said so, please feel free to smoke over whatever type of kernel hugepd mappings, and I'd trust you're the expert on how to trigger those paths. Since I got your attention, when working on this series I talked to David Gibson and just got to know that hugepd is actually a pure software idea. IIUC it means there's no PPC hardware that really understands the hugepd format at all, but only a "this is a huge page" hint for Linux. Considering that it _seems_ to play a similar role of cont_pXX here: do you think hugepd can have any chance to be implemented similarly like cont_pXX, or somehow share the code? For example, if hugepd is recognized only by Linux kernel itself, maybe there can be some special pgtable hint that can be attached to the cont_* entries, showing whether it's a "real cont_*" entry or a "hugepd" entry? IIUC it can be quite flexible because if hugepd only works for hash MMU so no hardware will even walk that radix table. But I can overlook important things here. It'll be definitely great if hugepd can be merged into some existing forms like a generic pgtable (IMHO cont_* is such case: it's the same as no cont_* entries for softwares, while hardware can accelerate with TLB hits on larger ranges). But I can be asking a very silly question here too, as I can overlook very important things. Thanks, -- Peter Xu _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel