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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 704B8C433FE for ; Thu, 14 Oct 2021 16:53:41 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id BE5506101D for ; Thu, 14 Oct 2021 16:53:40 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org BE5506101D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvack.org Received: by kanga.kvack.org (Postfix) id 3BEF6900002; Thu, 14 Oct 2021 12:53:40 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 36F406B0072; Thu, 14 Oct 2021 12:53:40 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 25D62900002; Thu, 14 Oct 2021 12:53:40 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0171.hostedemail.com [216.40.44.171]) by kanga.kvack.org (Postfix) with ESMTP id 164B06B0071 for ; Thu, 14 Oct 2021 12:53:40 -0400 (EDT) Received: from smtpin19.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id C30BA18121F93 for ; Thu, 14 Oct 2021 16:53:39 +0000 (UTC) X-FDA: 78695639358.19.B9CCC64 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf08.hostedemail.com (Postfix) with ESMTP id B220430000AA for ; Thu, 14 Oct 2021 16:53:38 +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=AP05hDHW3jnp/8SKRcKLGgYaYjlel0b7xcFX3XAvvcQ=; b=WrkEY1NXq2B+vb3ir5rv+AxuPg cQLMnetlragb8L7WOZfh2WRUI5amnBlq8PlDunGKpTP6nGfIOIcYnWFF9UuTTFHIVKNRkM+vx+2Dy COMPWhQnxXy5qu73bdmTU7k0CJi1gGHXUvMqopwf5oBqTkX1+Q9pDzR3CrmrDDfC0EKlK4c8ZaMK7 sDvAfPn5lhegMNYQnZ7pKkzJ51QUPqeOSUOnmsleGDbkMn9aU+nkXYPeWigSuK38OwbcmnkhuI+9K mGfn626q1LkPL8F2E1A8enzyO5vqH5MPRzxIZ3FVVVW2IH8w34E9HLHyAbDdNUkG177gXsh8NBe0L iOqMMBMQ==; Received: from willy by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1mb3y7-008TLK-Fz; Thu, 14 Oct 2021 16:52:58 +0000 Date: Thu, 14 Oct 2021 17:52:35 +0100 From: Matthew Wilcox To: Alex Sierra Cc: akpm@linux-foundation.org, 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, jgg@nvidia.com, jglisse@redhat.com, apopple@nvidia.com Subject: Re: [PATCH v1 2/2] mm: remove extra ZONE_DEVICE struct page refcount Message-ID: References: <20211014153928.16805-1-alex.sierra@amd.com> <20211014153928.16805-3-alex.sierra@amd.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20211014153928.16805-3-alex.sierra@amd.com> Authentication-Results: imf08.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b=WrkEY1NX; dmarc=none; spf=none (imf08.hostedemail.com: domain of willy@infradead.org has no SPF policy when checking 90.155.50.34) smtp.mailfrom=willy@infradead.org X-Stat-Signature: mi1x5uoenz6jbd34k16f435yobyzwzw8 X-Rspamd-Queue-Id: B220430000AA X-Rspamd-Server: rspam01 X-HE-Tag: 1634230418-751143 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 Thu, Oct 14, 2021 at 10:39:28AM -0500, Alex Sierra wrote: > From: Ralph Campbell > > ZONE_DEVICE struct pages have an extra reference count that complicates the > code for put_page() and several places in the kernel that need to check the > reference count to see that a page is not being used (gup, compaction, > migration, etc.). Clean up the code so the reference count doesn't need to > be treated specially for ZONE_DEVICE. > > Signed-off-by: Ralph Campbell > Signed-off-by: Alex Sierra > Reviewed-by: Christoph Hellwig Reviewed-by: Matthew Wilcox (Oracle)