From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f53.google.com (mail-wm0-f53.google.com [74.125.82.53]) by kanga.kvack.org (Postfix) with ESMTP id 6F6D46B025F for ; Mon, 21 Mar 2016 04:50:01 -0400 (EDT) Received: by mail-wm0-f53.google.com with SMTP id p65so112587421wmp.0 for ; Mon, 21 Mar 2016 01:50:01 -0700 (PDT) Received: from mx2.suse.de (mx2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id rx6si14033633wjb.4.2016.03.21.01.50.00 for (version=TLS1 cipher=AES128-SHA bits=128/128); Mon, 21 Mar 2016 01:50:00 -0700 (PDT) Date: Mon, 21 Mar 2016 09:50:26 +0100 From: Jan Kara Subject: Re: [PATCH 62/71] udf: get rid of PAGE_CACHE_* and page_cache_{get,release} macros Message-ID: <20160321085026.GC30819@quack.suse.cz> References: <1458499278-1516-1-git-send-email-kirill.shutemov@linux.intel.com> <1458499278-1516-63-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: <1458499278-1516-63-git-send-email-kirill.shutemov@linux.intel.com> Sender: owner-linux-mm@kvack.org List-ID: To: "Kirill A. Shutemov" Cc: Andrew Morton , Alexander Viro , Linus Torvalds , Christoph Lameter , Matthew Wilcox , linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, Jan Kara On Sun 20-03-16 21:41:09, 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: Jan Kara Reviewed-by: Jan Kara Honza -- Jan Kara SUSE Labs, CR -- 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