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=-0.6 required=3.0 tests=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 2D2D2C47254 for ; Tue, 5 May 2020 17:25:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 03D17206FA for ; Tue, 5 May 2020 17:25:24 +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="exxQx5pQ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729553AbgEERZX (ORCPT ); Tue, 5 May 2020 13:25:23 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50800 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1729199AbgEERZX (ORCPT ); Tue, 5 May 2020 13:25:23 -0400 Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:e::133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0DF2FC061A0F; Tue, 5 May 2020 10:25:23 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.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=YxvvGR/vhOw4v98ZqlbbGMF6Ldqy0REYQuhYbCnAaPM=; b=exxQx5pQ2uugq+dUB7Jv1Aw+QB wYH8ARG/d9mqLuyLjjSG28V3/XmroRtH1Lg/WH/Ww99MdIx5yfgH25yNnhr1Xm+qApVr+PnkesnBo aT+4QkBGhHIZxLr7V/QJ2C038AFmwQt3KlQxXs2ysMg71e9rwxESgOzh0j++KyyIOFsGdTpwdUkZA 7/k/aQCCLK8aUNjWK2y+llcA5gp5SCtA1s1SVDUpcPlzt1f4njFiF7CIVjIUITMFl61meIEulH0IJ IMNwWQkvjonlIsfQxWuVg6j6yc55YQKT5B94chB/3VZe0cPpWjUdnVkYIgA5wWYOZ+QgB33iumgVj jHgRw+OA==; Received: from willy by bombadil.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1jW1Jo-00088X-Tj; Tue, 05 May 2020 17:25:20 +0000 Date: Tue, 5 May 2020 10:25:20 -0700 From: Matthew Wilcox To: Zhen Lei Cc: Minchan Kim , Nitin Gupta , Sergey Senozhatsky , Jens Axboe , linux-block , Andrew Morton , linux-mm , Alasdair Kergon , Mike Snitzer , dm-devel , Song Liu , linux-raid , linux-kernel Subject: Re: [PATCH 2/4] mm/swap: use SECTORS_PER_PAGE_SHIFT to clean up code Message-ID: <20200505172520.GI16070@bombadil.infradead.org> References: <20200505115543.1660-1-thunder.leizhen@huawei.com> <20200505115543.1660-3-thunder.leizhen@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200505115543.1660-3-thunder.leizhen@huawei.com> Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On Tue, May 05, 2020 at 07:55:41PM +0800, Zhen Lei wrote: > +++ b/mm/swapfile.c > @@ -177,8 +177,8 @@ static int discard_swap(struct swap_info_struct *si) > > /* Do not discard the swap header page! */ > se = first_se(si); > - start_block = (se->start_block + 1) << (PAGE_SHIFT - 9); > - nr_blocks = ((sector_t)se->nr_pages - 1) << (PAGE_SHIFT - 9); > + start_block = (se->start_block + 1) << SECTORS_PER_PAGE_SHIFT; > + nr_blocks = ((sector_t)se->nr_pages - 1) << SECTORS_PER_PAGE_SHIFT; Thinking about this some more, wouldn't this look better? start_block = page_sectors(se->start_block + 1); nr_block = page_sectors(se->nr_pages - 1);