mirror of https://lore.kernel.org/lkml/
 help / color / mirror / Atom feed
From: "Michael Kerrisk" <mtk.manpages@googlemail.com>
To: "Davide Libenzi" <davidel@xmailserver.org>
Cc: "Andrew Morton" <akpm@linux-foundation.org>,
	lkml <linux-kernel@vger.kernel.org>,
	tytso@thunk.org, "Thomas Gleixner" <tglx@linutronix.de>,
	"Greg KH" <gregkh@suse.de>, "Christoph Hellwig" <hch@lst.de>,
	"Linux Torvalds" <torvalds@linux-foundation.org>
Subject: Re: Tesing of / bugs in new timerfd API
Date: Mon, 17 Dec 2007 14:27:23 +0100	[thread overview]
Message-ID: <cfd18e0f0712170527k6e2f20ddq8d3abc367aa20661@mail.gmail.com> (raw)
In-Reply-To: <Pine.LNX.4.64.0712161210120.14339@alien.or.mcafeemobile.com>

Hi Davide,

On 12/16/07, Davide Libenzi <davidel@xmailserver.org> wrote:
> On Fri, 14 Dec 2007, Michael Kerrisk wrote:
>
> > You snipped my example that demonstrated the problem.  Both of the
> > following runs create a timer that expires 10 seconds from "now", but
> > observe the difference in the value returned by timerfd_gettime():
> >
> > $ ./timerfd_test 10         # does not use TFD_TIMER_ABSTIME
> > Initial setting for settime:   value=10.000, interval=0.000
> > ./timerfd_test> g
> > (elapsed time=  1)
> > Current value:                 value=346.448, interval=0.000
> >
> > $ ./timerfd_test -a 10      # uses TFD_TIMER_ABSTIME
> > Initial setting for settime:   value=1197630855.254, interval=0.000
> > ./timerfd_test> g
> > (elapsed time=  1)
> > Current value:                 value=1197630855.254, interval=0.000
> >
> > Either there's an inconsistency here depending on the use of
> > TFD_TIMER_ABSTIME, or there is a bug in my understanding or my test
> program
> > (but so far I haven't spotted that bug ;-).).
>
> Can you try the two patches below? I tried them on my 32 bit box (one of
> the rare beasts still lingering around here) and it seems to be working
> fine (those go on top of the previous ones).

Against 2.6.24-rc5, I applied first your earlier patches ("v3") and
then the newest patch.  My tests confirm that:

> This fixed the 32 bit tick-count truncation, and makes the time returned
> to be the remaining time till the next expiration.

Are you going to resubmit a new patch set that includes these latest changes?

Michael

  reply	other threads:[~2007-12-17 13:27 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-12-13 14:36 Michael Kerrisk
2007-12-13 21:49 ` Davide Libenzi
2007-12-13 22:16   ` Michael Kerrisk
2007-12-14  0:13     ` Davide Libenzi
2007-12-14 11:25       ` Michael Kerrisk
2007-12-16 20:15         ` Davide Libenzi
2007-12-17 13:27           ` Michael Kerrisk [this message]
2007-12-17 15:47             ` Davide Libenzi

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=cfd18e0f0712170527k6e2f20ddq8d3abc367aa20661@mail.gmail.com \
    --to=mtk.manpages@googlemail.com \
    --cc=akpm@linux-foundation.org \
    --cc=davidel@xmailserver.org \
    --cc=gregkh@suse.de \
    --cc=hch@lst.de \
    --cc=linux-kernel@vger.kernel.org \
    --cc=tglx@linutronix.de \
    --cc=torvalds@linux-foundation.org \
    --cc=tytso@thunk.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

all inboxes | Powered by JetHome®