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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 306AEC433EF for ; Mon, 11 Jul 2022 14:22:34 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 8EA8F6B00EF; Mon, 11 Jul 2022 10:22:33 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 899756B00F0; Mon, 11 Jul 2022 10:22:33 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 789116B00F1; Mon, 11 Jul 2022 10:22:33 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id 6A0A16B00EF for ; Mon, 11 Jul 2022 10:22:33 -0400 (EDT) Received: from smtpin25.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay08.hostedemail.com (Postfix) with ESMTP id 20D9E20CEE for ; Mon, 11 Jul 2022 14:22:33 +0000 (UTC) X-FDA: 79675034586.25.150A0A4 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf19.hostedemail.com (Postfix) with ESMTP id 432AA1A0051 for ; Mon, 11 Jul 2022 14:22:32 +0000 (UTC) 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=rcQF7iugd2cu8An1gTYADBIF1lWVn+jc8HlNL1UeLoM=; b=gVStaT9Kg0MMbppoH83xjPscGs IFbnv81Y2Qux27iyh2Ytl5RYRUv/rrc/FF853SfUcRswpEscsP7xj4ckdRrrmFlKVPdCkfjDFWPJV a6BE4mHwC98MjNV7ILSxNmudVQYo/YACzEjfygVSi9TN8tlCjTOLQQUWznoWY739TfIIQPlyYa2mY OsowUrkakCcxofte6qfDxJ43ipH5CUD9JiHbZadiUR5ps47qHAgjlAHSPevIEYvLqBZsGOC2JKq8i KFOLAViCUYEoLKdytMRp4fnJce4T+X2CknDxNQzRotjz/y2NXtCO92RF15eLW0OoWR33g46bZ3vax fHzP8VIg==; Received: from willy by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1oAtxM-0060dO-5n; Mon, 11 Jul 2022 14:00:12 +0000 Date: Mon, 11 Jul 2022 15:00:12 +0100 From: Matthew Wilcox To: David Hildenbrand Cc: Alex Sierra , jgg@nvidia.com, Felix.Kuehling@amd.com, linux-mm@kvack.org, rcampbell@nvidia.com, linux-ext4@vger.kernel.org, linux-xfs@vger.kernel.org, amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, hch@lst.de, jglisse@redhat.com, apopple@nvidia.com, akpm@linux-foundation.org Subject: Re: [PATCH v8 07/15] mm/gup: migrate device coherent pages when pinning instead of failing Message-ID: References: <20220707190349.9778-1-alex.sierra@amd.com> <20220707190349.9778-8-alex.sierra@amd.com> <2c4dd559-4fa9-f874-934f-d6b674543d0f@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <2c4dd559-4fa9-f874-934f-d6b674543d0f@redhat.com> ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1657549352; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=rcQF7iugd2cu8An1gTYADBIF1lWVn+jc8HlNL1UeLoM=; b=3yyZa8mL/Pz4rH29UHW8L4uvGxjbYUITe95RZVQZKMJfjjKQqreTcgDviLGTT1XEBBZnuJ YbVnwP0VRxQdhDHoFV/bMt64j9OhRgpcI6NvnlsheVe4unUdkTxU8cKzpy4lS83Gh64PBz 5Ve1R059DB3/TbOF83sbeS92zXAkV4w= ARC-Authentication-Results: i=1; imf19.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b=gVStaT9K; spf=none (imf19.hostedemail.com: domain of willy@infradead.org has no SPF policy when checking 90.155.50.34) smtp.mailfrom=willy@infradead.org; dmarc=none ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1657549352; a=rsa-sha256; cv=none; b=yJ+l/4kTcL+AUazVyvSvELmkcV1BGJnj2ufF8FhfdV48WzNBU0n2tlE8yJALO7WC0RjOlP T0mwj/Jc9Q2j7xWMpEvZ7d8TUR5S3WPB11pImEbX0RIKtHmFUqCEHdl4dGDwMAJlMRp3Q0 hnmH/iNeKH3UXBKzTpgxkDOyQof4RXo= X-Rspamd-Server: rspam02 X-Stat-Signature: 8m4rp54zndtfh3tyak3niu1ycww3c714 X-Rspamd-Queue-Id: 432AA1A0051 X-Rspam-User: Authentication-Results: imf19.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b=gVStaT9K; spf=none (imf19.hostedemail.com: domain of willy@infradead.org has no SPF policy when checking 90.155.50.34) smtp.mailfrom=willy@infradead.org; dmarc=none X-HE-Tag: 1657549352-83689 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Mon, Jul 11, 2022 at 03:35:42PM +0200, David Hildenbrand wrote: > > + /* > > + * Device coherent pages are managed by a driver and should not > > + * be pinned indefinitely as it prevents the driver moving the > > + * page. So when trying to pin with FOLL_LONGTERM instead try > > + * to migrate the page out of device memory. > > + */ > > + if (folio_is_device_coherent(folio)) { > > + WARN_ON_ONCE(PageCompound(&folio->page)); > > Maybe that belongs into migrate_device_page()? ... and should be simply WARN_ON_ONCE(folio_test_large(folio)). No need to go converting it back into a page in order to test things that can't possibly be true.