linux-kernel - Re: PROBLEM: tickless scheduling

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <AANLkTilb_CGBolyv5Ps9VuhNxFZKtjck4om4G21ICaif@mail.gmail.com>
Date:	Wed, 12 May 2010 15:54:25 -0400
From:	Donald Allen <donaldcallen@...il.com>
To:	john stultz <johnstul@...ibm.com>
Cc:	linux-kernel@...r.kernel.org, Thomas Gleixner <tglx@...utronix.de>
Subject: Re: PROBLEM: tickless scheduling

Before doing what you asked, I ran my home-brew backup script, which
tars up the whole machine, save my home directory, to a big sata drive
in a usb shoebox. I did so by booting the most recent Arch Linux
install/live CD (while I use Slackware, the Slackware install CDs are
not suitable for this sort of thing, having very old versions of
things like tar). While doing so, I observed exactly the same symptoms
I did with the Slackware 13.1 install, which I described in the bug
report. So rather than messing with the hard-won custom kernel that I
now have installed on the netbook, I am attaching the various things
from /proc gathered with the Arch kernel running. Yes, it's a somewhat
older kernel (2.6.30), but I'm hoping that things haven't changed much
in tickless land. If that's not the case, then I will attempt to
reproduce this with the newer kernel on the Slackware 13.1 install
DVD. Let me know if you need me to do this. The attached tar file is
bzip2-compressed, so you want xjf to extract.

/Don

On Mon, May 10, 2010 at 9:52 PM, Donald Allen <donaldcallen@...il.com> wrote:
> On Mon, May 10, 2010 at 9:12 PM, john stultz <johnstul@...ibm.com> wrote:
>> On Mon, 2010-05-10 at 20:59 -0400, Donald Allen wrote:
>>> On Mon, May 10, 2010 at 8:54 PM, john stultz <johnstul@...ibm.com> wrote:
>>> > On Mon, May 10, 2010 at 5:18 PM, Donald Allen <donaldcallen@...il.com> wrote:
>>> >> 1. Network file transfers and fscks stop on Toshiba netbook unless
>>> >> system receives external events
>>> >
>>> > Can you provide /proc/timer_list output?
>>>
>>> Attached, but again, this is from the system running with tickless disabled.
>>
>> Is it possible to boot with the kernel showing the issue and provide the
>> details?
>
> It's a minor pain, but I'll do it.
>
>>
>>
>>> > I assume booting with nohz=off from grub resolves the issue?
>>>
>>> Didn't know about the boot-time option (thanks for pointing it out),
>>> but I wanted to build a custom kernel anyway, so i did so and disabled
>>> tickless.
>>
>> Ok. It may still be of value to know booting with nohz=off does avoid
>> the problem.
>
> Ok. When I've got the original kernel installed and bootable, I'll try
> it. I won't be able to get to this for a day or so.
>
> /Don
>
>>
>>
>> thanks
>> -john
>>
>>
>

Download attachment "tickless.tbz2" of type "application/octet-stream" (13078 bytes)