public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: William Lee Irwin III <wli@holomorphy.com>
To: Falk Hueffner <falk.hueffner@student.uni-tuebingen.de>
Cc: lkml <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] make jiffies wrap 5 min after boot
Date: Sun, 16 Feb 2003 04:04:47 -0800	[thread overview]
Message-ID: <20030216120447.GN29983@holomorphy.com> (raw)
In-Reply-To: <871y281m2d.fsf@student.uni-tuebingen.de>

Muli Ben-Yehuda <mulix@mulix.org> writes:
>> I have no idea if that's what wli meant, but -1UL is only "all ones"
>> in a 2's complement binary representation. 

On Sun, Feb 16, 2003 at 12:50:34PM +0100, Falk Hueffner wrote:
> No. Wraparound of unsigned types is well-defined. -1UL must be the
> largest possible unsigned long value, which must consist of only 1
> bits (except for possible padding bits).
> Of course, no machines with ones-complement (or padding bits, or
> integer trap representations, or any of the other ISO braindamages)
> exist, so this is mostly irrelevant anyway.

In the "obvious" sense, -1UL is an oxymoron, as -1 is inherently signed,
and the "UL" says "unsigned".

It's aesthetic. It's a violation of what I consider good taste to
do signed bit twiddling on an unsigned value and/or vice-versa.
Regardless of what ISO and/or Linux may or may not support, the habits
ingrained in me wrt. portability say the assumption must not be made.

YMMV.

-- wli

  reply	other threads:[~2003-02-16 11:55 UTC|newest]

Thread overview: 33+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2003-02-02 22:55 [PATCH *] use 64 bit jiffies Tim Schmielau
2003-02-03  6:42 ` Denis Vlasenko
2003-02-03  8:28   ` Matti Aarnio
2003-02-03  8:47     ` Tim Schmielau
2003-02-03  8:55       ` Matti Aarnio
2003-02-04 13:00         ` Tim Schmielau
2003-02-04  6:41     ` Denis Vlasenko
2003-02-04  8:27       ` Robert de Bath
2003-02-04  8:41         ` Denis Vlasenko
2003-02-04  9:29       ` Jörn Engel
2003-02-04 13:04         ` Tim Schmielau
2003-02-17 13:55           ` Jörn Engel
2003-02-17 14:02             ` Tim Schmielau
2003-02-17 14:15             ` Matti Aarnio
2003-02-17 14:23               ` Tim Schmielau
2003-02-04 17:37       ` Randy.Dunlap
2003-02-16  1:37         ` [PATCH] make jiffies wrap 5 min after boot Tim Schmielau
2003-02-16  2:08           ` Anton Blanchard
2003-02-16  2:43             ` William Lee Irwin III
2003-02-16  2:50               ` Michael Vergoz
2003-02-16  6:37               ` Robert Love
2003-02-16  7:16                 ` Muli Ben-Yehuda
2003-02-16 11:50                   ` Falk Hueffner
2003-02-16 12:04                     ` William Lee Irwin III [this message]
2003-02-11 20:50       ` [patch] jiffies wrap fixes for 2.5.60 Tim Schmielau
2003-02-11 21:31         ` Roger Larsson
2003-02-12 12:09           ` Tim Schmielau
2003-02-05 11:42 ` use 64 bit jiffies broke HZ=100 case (and fix) Oleg Drokin
2003-02-05 12:22   ` Tim Schmielau
     [not found] <Pine.LNX.4.33L2.0302040935230.6174-100000@dragon.pdx.osdl.net.suse.lists.linux.kernel>
     [not found] ` <Pine.LNX.4.33.0302160232120.7975-100000@gans.physik3.uni-rostock.de.suse.lists.linux.kernel>
     [not found]   ` <20030216020808.GF9833@krispykreme.suse.lists.linux.kernel>
2003-02-16  6:36     ` [PATCH] make jiffies wrap 5 min after boot Andi Kleen
2003-02-16  6:56       ` Andrew Morton
2003-02-16  7:00         ` Andi Kleen
2003-02-16  8:10         ` Tim Schmielau

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20030216120447.GN29983@holomorphy.com \
    --to=wli@holomorphy.com \
    --cc=falk.hueffner@student.uni-tuebingen.de \
    --cc=linux-kernel@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox