From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ed1-f69.google.com (mail-ed1-f69.google.com [209.85.208.69]) by kanga.kvack.org (Postfix) with ESMTP id E7A408E0001 for ; Fri, 21 Dec 2018 09:06:45 -0500 (EST) Received: by mail-ed1-f69.google.com with SMTP id c3so6142490eda.3 for ; Fri, 21 Dec 2018 06:06:45 -0800 (PST) Received: from mx1.suse.de (mx2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id 18-v6si7374231ejw.229.2018.12.21.06.06.44 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 21 Dec 2018 06:06:44 -0800 (PST) Subject: Re: [PATCH] mm: Define VM_(MAX|MIN)_READAHEAD via sizes.h constants References: <20181221125314.5177-1-nborisov@suse.com> <20181221132423.GA10600@bombadil.infradead.org> From: Nikolay Borisov Message-ID: <8c5224ce-ba67-2afc-3864-051b8220a87a@suse.com> Date: Fri, 21 Dec 2018 16:06:42 +0200 MIME-Version: 1.0 In-Reply-To: <20181221132423.GA10600@bombadil.infradead.org> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: owner-linux-mm@kvack.org List-ID: To: Matthew Wilcox Cc: linux-mm@kvack.org, akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-afs@lists.infradead.org, linux-fsdevel@vger.kernel.org On 21.12.18 г. 15:24 ч., Matthew Wilcox wrote: > On Fri, Dec 21, 2018 at 02:53:14PM +0200, Nikolay Borisov wrote: >> All users of the aformentioned macros convert them to kbytes by >> multplying. Instead, directly define the macros via the aptly named >> SZ_16K/SZ_128K ones. Also remove the now redundant comments explaining >> that VM_* are defined in kbytes it's obvious. No functional changes. > > Actually, all users of these constants convert them to pages! > >> + q->backing_dev_info->ra_pages = VM_MAX_READAHEAD / PAGE_SIZE; >> + sb->s_bdi->ra_pages = VM_MAX_READAHEAD / PAGE_SIZE; >> + sb->s_bdi->ra_pages = VM_MAX_READAHEAD / PAGE_SIZE; >> + sb->s_bdi->ra_pages = VM_MAX_READAHEAD / PAGE_SIZE; >> + sb->s_bdi->ra_pages = VM_MAX_READAHEAD / PAGE_SIZE; > >> -#define VM_MAX_READAHEAD 128 /* kbytes */ >> -#define VM_MIN_READAHEAD 16 /* kbytes (includes current page) */ >> +#define VM_MAX_READAHEAD SZ_128K >> +#define VM_MIN_READAHEAD SZ_16K /* includes current page */ > > So perhaps: > > #define VM_MAX_READAHEAD (SZ_128K / PAGE_SIZE) > > VM_MIN_READAHEAD isn't used, so just delete it? I thought about that but didn't know if people will complain that some times in the future we might need it. >