From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f46.google.com (mail-wm0-f46.google.com [74.125.82.46]) by kanga.kvack.org (Postfix) with ESMTP id EA56A6B0005 for ; Mon, 21 Mar 2016 09:42:21 -0400 (EDT) Received: by mail-wm0-f46.google.com with SMTP id r129so51007579wmr.1 for ; Mon, 21 Mar 2016 06:42:21 -0700 (PDT) Received: from mx2.suse.de (mx2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id r8si31121515wjq.3.2016.03.21.06.42.20 for (version=TLS1 cipher=AES128-SHA bits=128/128); Mon, 21 Mar 2016 06:42:20 -0700 (PDT) Date: Mon, 21 Mar 2016 14:41:51 +0100 From: David Sterba Subject: Re: [PATCH 22/71] btrfs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros Message-ID: <20160321134151.GI21722@suse.cz> Reply-To: dsterba@suse.cz References: <1458499278-1516-1-git-send-email-kirill.shutemov@linux.intel.com> <1458499278-1516-23-git-send-email-kirill.shutemov@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1458499278-1516-23-git-send-email-kirill.shutemov@linux.intel.com> Sender: owner-linux-mm@kvack.org List-ID: To: "Kirill A. Shutemov" Cc: Andrew Morton , Linus Torvalds , Alexander Viro , Chris Mason , Josef Bacik , linux-mm@kvack.org, Christoph Lameter , Matthew Wilcox , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org On Sun, Mar 20, 2016 at 09:40:29PM +0300, Kirill A. Shutemov wrote: > PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time ago > with promise that one day it will be possible to implement page cache with > bigger chunks than PAGE_SIZE. > > This promise never materialized. And unlikely will. > > We have many places where PAGE_CACHE_SIZE assumed to be equal to > PAGE_SIZE. And it's constant source of confusion on whether PAGE_CACHE_* > or PAGE_* constant should be used in a particular case, especially on the > border between fs and mm. > > Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much > breakage to be doable. > > Let's stop pretending that pages in page cache are special. They are not. > > The changes are pretty straight-forward: > > - << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> ; > > - PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN}; > > - page_cache_get() -> get_page(); > > - page_cache_release() -> put_page(); > > Signed-off-by: Kirill A. Shutemov > Cc: Chris Mason > Cc: Josef Bacik > Cc: David Sterba Acked-by: David Sterba -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org