From: Con Kolivas <kernel@kolivas.org>
To: "lk" <linux_kernel@patni.com>
Cc: "jeff shia" <tshxiayu@gmail.com>,
linux-kernel@vger.kernel.org, "robert love" <rml@novell.com>
Subject: Re: something about jiffies wraparound overflow
Date: Tue, 27 Dec 2005 20:05:21 +1100 [thread overview]
Message-ID: <200512272005.22440.kernel@kolivas.org> (raw)
In-Reply-To: <003201c60ac3$16692d90$5e91a8c0@patni.com>
On Tuesday 27 December 2005 19:54, lk wrote:
> As you mentioned the code for comparison:
> > /* code 2*/
> > unsigned long timeout = jiffies + HZ/2;
>
> the code has no problem with jiffies wrapping around
> as long as the values are compared in a right way.
> For a 32 bit platform the counter wraps around only once every 50 day
> when the value of HZ 1000. so if your code is prepared to face this event
> it will work fine.
In 2.6 we actually roll over 5 minutes after starting (the jiffy counter is
set to about 5 minutes from roll over); that was put in on purpose to pick up
wraparound bugs easily.
Cheers,
Con
next prev parent reply other threads:[~2005-12-27 9:05 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-12-27 4:46 something about jiffies wraparound overflow jeff shia
2005-12-27 8:54 ` lk
2005-12-27 9:05 ` Con Kolivas [this message]
2005-12-27 14:54 ` Ben Collins
[not found] <5oeWK-5Od-11@gated-at.bofh.it>
2005-12-27 10:06 ` Bodo Eggert
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=200512272005.22440.kernel@kolivas.org \
--to=kernel@kolivas.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux_kernel@patni.com \
--cc=rml@novell.com \
--cc=tshxiayu@gmail.com \
/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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.