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_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,T_DKIM_INVALID, URIBL_BLOCKED autolearn=ham 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 D2717C43143 for ; Fri, 22 Jun 2018 08:19:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8577E21722 for ; Fri, 22 Jun 2018 08:19:59 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="ITlEtCQq" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8577E21722 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arndb.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753987AbeFVIT4 (ORCPT ); Fri, 22 Jun 2018 04:19:56 -0400 Received: from mail-lj1-f193.google.com ([209.85.208.193]:45004 "EHLO mail-lj1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752464AbeFVITy (ORCPT ); Fri, 22 Jun 2018 04:19:54 -0400 Received: by mail-lj1-f193.google.com with SMTP id t12-v6so934927ljc.11 for ; Fri, 22 Jun 2018 01:19:53 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:sender:in-reply-to:references:from:date:message-id :subject:to:cc; bh=Njt7jcepfDhoRsfWskcm1WgxpOAtqsJvlnQTNa2O78s=; b=ITlEtCQqpRZvwpasoLGjIVrk7puOKKMLNafkFJr5BH55UH46PoRmfvLNFRI1vg4gz1 HxblcodhgwSj0V9lL4jb7sllSbu6kAo+pM8lIoHZScyJd0tWSluM+AGwjvywwN9Ys2yW 4IfPF52F+ILHrcFOK/nMLtM5WmLrx9RNtPT4lL67HL4tq1CVkVJWm4jMSEvbCo5hOC3y V+orfOEUgmddai0QkN8LTvdhunpibkWQ/aj+ZlNmN0Lt/iyoc02PU1r+FP6d1xveAZEu r292InRRb6n6VpIpSJPIG2IQXybdR00Rrtn/wmBBR46gBK4+0USHTSYzXT83VqBO1VOX 9XYw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:sender:in-reply-to:references:from :date:message-id:subject:to:cc; bh=Njt7jcepfDhoRsfWskcm1WgxpOAtqsJvlnQTNa2O78s=; b=ToPW3/Ma0nhRZbrjMmhWWCfBeo2uSeAmS8yxXEK3vXWXNHQzbvbIk1+gdF1GInr2EF hOmL2PEtgmi1KTtSbUgQQzUnzZnVndxSzlzR0/m+UERTbA2WQXnI7/tiL542jhGINNJH /Qs6kmo77rHJUJBQhnK3oRxB5OIbqZgtPZ9A/KAMzATSW98wc5Nrmn+xckqfHRLr8aTu uuULC71/bnqyqmlvr613NVe/WDyAFHvIPIYGROyL3M8INOUXxHMW7nllxizHRqa/zIrt G5BfLCnhTkfQuGBPK7cV+UEN2YPMV7a/AJa+MrmJYhwDB+p2nqGjR2QXdfIWefSA0MFu onOg== X-Gm-Message-State: APt69E20/ne0dYmdci4uh6gsDDoxoFjLc3aMopDypXmGmAyLiaYD/VAB FB/+r/8hWAqT6V4ZUVMdyibMnSLk+dtAIwTSWIpsaA== X-Google-Smtp-Source: ADUXVKLFq/ojvRo2hgOATo6fWL1v5Nl4AAdg6KvLnf6QK1BIJAZnL0n8Dz2VtLJN7rRhE+vfpnz17of0xQB6JhaBbZw= X-Received: by 2002:a2e:804c:: with SMTP id p12-v6mr551477ljg.22.1529655592718; Fri, 22 Jun 2018 01:19:52 -0700 (PDT) MIME-Version: 1.0 Received: by 2002:a2e:56c8:0:0:0:0:0 with HTTP; Fri, 22 Jun 2018 01:19:51 -0700 (PDT) In-Reply-To: <20180622075421.16001-1-geert@linux-m68k.org> References: <20180622075421.16001-1-geert@linux-m68k.org> From: Arnd Bergmann Date: Fri, 22 Jun 2018 10:19:51 +0200 X-Google-Sender-Auth: ap4f3oXu6pDEMpgueVKRGDH2jWM Message-ID: Subject: Re: [PATCH v2] time: Make sure jiffies_to_msecs() preserves non-zero time periods To: Geert Uytterhoeven Cc: John Stultz , Thomas Gleixner , Stephen Boyd , Linux Kernel Mailing List Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jun 22, 2018 at 9:54 AM, Geert Uytterhoeven wrote: > For the common cases where 1000 is a multiple of HZ, or HZ is a multiple > of 1000, jiffies_to_msecs() never returns zero when passed a non-zero > time period. > > However, if HZ > 1000 and not an integer multiple of 1000 (e.g. 1024 or > 1200, as used on alpha and DECstation), jiffies_to_msecs() may return > zero for small non-zero time periods. This may break code that relies > on receiving back a non-zero value. > > jiffies_to_usecs() does not need such a fix, as does > not support values of HZ larger than 12287, thus rejecting any > problematic huge values of HZ. > > Signed-off-by: Geert Uytterhoeven > --- Looks good to me, Reviewed-by: Arnd Bergmann