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 3EC9EC433EF for ; Thu, 14 Oct 2021 16:53:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2B70561152 for ; Thu, 14 Oct 2021 16:53:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232638AbhJNQ4C (ORCPT ); Thu, 14 Oct 2021 12:56:02 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45344 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230244AbhJNQ4B (ORCPT ); Thu, 14 Oct 2021 12:56:01 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9D6A1C061570; Thu, 14 Oct 2021 09:53:56 -0700 (PDT) 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> Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org 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)