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=-3.5 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,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 BE701C433DF for ; Wed, 26 Aug 2020 14:54:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9473221741 for ; Wed, 26 Aug 2020 14:54:56 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="jgWPg7Yh" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728411AbgHZOyz (ORCPT ); Wed, 26 Aug 2020 10:54:55 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34278 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728420AbgHZOyt (ORCPT ); Wed, 26 Aug 2020 10:54:49 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3EF2CC061574; Wed, 26 Aug 2020 07:54:49 -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=ZzsUdze8ZxaoitbjHVszLwTb08J5c1Hia45JcEtljE4=; b=jgWPg7Yh9RXA+VJEzrAs7yZ/cv +6tN1LkkGojOebzqvD2JVawUFjCGG8yz0u3rvFz6guuz0w3WLWXCE2k+oUxZZAW0Pw8Z4yBYImyEb eDFlYc5+atk/9+/V+mG6AfdNRYL1RsPPEgmLItcpiUa60+BoQv8XhlBO6Mg9Y50S1qMzHBW7biAD6 IKG4ppnZvdtgSSnPglew/3F6cvM+/E0QB+NL0Bz4Cd/IsDMhZIcs2xcP6T3HvkjVevxf54/EddYV7 1s2e3+aaPq/jvT8+AYFsONTFGnqNFl/zEhPqPGbwgccPvl9AACur8zEmREPk7vnlcEvygyUxxt5YY lRKWXq3Q==; Received: from willy by casper.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1kAwoY-0001wl-7b; Wed, 26 Aug 2020 14:54:14 +0000 Date: Wed, 26 Aug 2020 15:54:14 +0100 From: Matthew Wilcox To: Johannes Weiner Cc: linux-mm@kvack.org, Andrew Morton , Hugh Dickins , William Kucharski , Jani Nikula , Alexey Dobriyan , Chris Wilson , Matthew Auld , Huang Ying , intel-gfx@lists.freedesktop.org, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 2/8] mm: Use find_get_swap_page in memcontrol Message-ID: <20200826145414.GS17456@casper.infradead.org> References: <20200819184850.24779-1-willy@infradead.org> <20200819184850.24779-3-willy@infradead.org> <20200826142002.GA988805@cmpxchg.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200826142002.GA988805@cmpxchg.org> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Aug 26, 2020 at 10:20:02AM -0400, Johannes Weiner wrote: > On Wed, Aug 19, 2020 at 07:48:44PM +0100, Matthew Wilcox (Oracle) wrote: > > + return find_get_swap_page(vma->vm_file->f_mapping, > > + linear_page_index(vma, addr)); > > The refactor makes sense to me, but the name is confusing. We're not > looking for a swap page, we're primarily looking for a file page in > the page cache mapping that's handed in. Only in the special case > where it's a shmem mapping and there is a swap entry do we consult the > auxiliary swap cache. > > How about find_get_page_or_swapcache()? find_get_page_shmemswap()? > Maybe you have a better idea. It's a fairly specialized operation that > isn't widely used, so a longer name isn't a bad thing IMO. Yeah, I had trouble with the naming here too. get_page_even_from_swap() find_get_shmem_page() or maybe refactor the whole thing: struct page *page = find_get_entry(mapping, index); page = find_swap_page(mapping, page); struct page *find_swap_page(struct address_space *mapping, struct page *page) { swp_entry_t swp; struct swap_info_struct *si; if (!xa_is_value(page)) return page; if (!shmem_mapping(mapping)) return NULL; ... }