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=-7.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS autolearn=unavailable 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 CF529C33C99 for ; Tue, 7 Jan 2020 11:43:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 979D42070E for ; Tue, 7 Jan 2020 11:43:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1578397433; bh=1j+UxKz7dqhiKpF1JjsOky8D5Km/ZHINtsX3lKlGj90=; h=References:In-Reply-To:From:Date:Subject:To:Cc:List-ID:From; b=xl5fqVo6rsaQzlunPFGW4SntTgJTiLmrtyOUFqMTzu2F29PzMhxLcp02oxQdfHHbe HsrpDbtfM/jvdFj4wRUwEQ4y6tkPz70JmVK1yiSQWO3RC/eUeqaUzUCSihUS4P7vxl +sDfV9Bpe0Xbgza/+b1iZoaUxw/jFRud7iNLiCXQ= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727273AbgAGLnx (ORCPT ); Tue, 7 Jan 2020 06:43:53 -0500 Received: from mail-ot1-f68.google.com ([209.85.210.68]:34422 "EHLO mail-ot1-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726690AbgAGLnx (ORCPT ); Tue, 7 Jan 2020 06:43:53 -0500 Received: by mail-ot1-f68.google.com with SMTP id a15so76062126otf.1; Tue, 07 Jan 2020 03:43:52 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=zJ7Soe4Ipf76O97lFC/HUE2dza3yg3mUCQ8NQLtNlnw=; b=lkgZ8aa1AIVKUV2EGHcXkmkOU5S/2wz3ZW5rrb87BOb3AxAFphlRRcxrC3HpqO3l1q 8/WNh/leB1S1V1de/kaAfmGAC0xYsn28nUU6EHUfe1NMxjcKAmiewE/TJWRLqztI6uWZ hMOlKMGV3mpnyskM4Hxu5abiwq8cSR8gl3566R1DHEhfg93KOYAEkXQX3vfbJhUtIsRC lQS0D425axUl3EmRKZFZeigpH5i0qbzWPeMBIwyqmhlXzHaUHftqS7p38GB+SU0oNmGZ PG9Uwpok6ux4/20izCbMb1domRr3vbtzvsDtdFNQGmNLG4VduzGYsFv3IkZpxuxVon5M tLnw== X-Gm-Message-State: APjAAAWii/xo/5G34xH/DfjHW3k0+bUiJFNhAZQFOHbS5m+bvleRDDkj fgTeWACCbRahtGpSftaep6yv20HNYGSXx6RmQKBiUBYR X-Google-Smtp-Source: APXvYqwJHuZIOtRj1OEJTcGQRETFctkZnZR8kHx+hRWaSra/ov5lEOtxzfZcq5CbtlubpiBfAtssc1Qokba+aMrab8I= X-Received: by 2002:a05:6830:3003:: with SMTP id a3mr15682871otn.118.1578397432443; Tue, 07 Jan 2020 03:43:52 -0800 (PST) MIME-Version: 1.0 References: <20200103155458.21707-1-wenyang@linux.alibaba.com> In-Reply-To: <20200103155458.21707-1-wenyang@linux.alibaba.com> From: "Rafael J. Wysocki" Date: Tue, 7 Jan 2020 12:43:41 +0100 Message-ID: Subject: Re: [PATCH] kernel/power/snapshot.c: improve arithmetic divisions To: Wen Yang Cc: "Rafael J. Wysocki" , Len Brown , Pavel Machek , Linux PM , Linux Kernel Mailing List Content-Type: text/plain; charset="UTF-8" Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org On Fri, Jan 3, 2020 at 4:55 PM Wen Yang wrote: > > do_div() does a 64-by-32 division. Use div64_u64() instead of > do_div() if the divisor is u64, to avoid truncation to 32-bit. > This change also cleans up code a tad. > > Signed-off-by: Wen Yang > Cc: "Rafael J. Wysocki" > Cc: Len Brown > Cc: Pavel Machek > Cc: linux-pm@vger.kernel.org > Cc: linux-kernel@vger.kernel.org > --- > kernel/power/snapshot.c | 4 +--- > 1 file changed, 1 insertion(+), 3 deletions(-) > > diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c > index 26b9168..8a6eaf7 100644 > --- a/kernel/power/snapshot.c > +++ b/kernel/power/snapshot.c > @@ -1566,9 +1566,7 @@ static unsigned long preallocate_image_highmem(unsigned long nr_pages) > */ > static unsigned long __fraction(u64 x, u64 multiplier, u64 base) > { > - x *= multiplier; > - do_div(x, base); > - return (unsigned long)x; > + return div64_u64(x * multiplier, base); > } > > static unsigned long preallocate_highmem_fraction(unsigned long nr_pages, > -- Applied as 5.6 material under a new subject ("PM: hibernate: improve arithmetic division in preallocate_highmem_fraction()"), thanks!