linux-kernel - Re: linux-2.6.23

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: <200710120053.20202.rc.poison@gmail.com>
Date:	Fri, 12 Oct 2007 00:53:19 +0200
From:	poison <rc.poison@...il.com>
To:	Helmut Toplizer <bgrpt@...litzer.net>
Cc:	linux-kernel@...r.kernel.org, Ingo Molnar <mingo@...e.hu>
Subject: Re: linux-2.6.23 - acting funny

Hi =)

On Thursday 11 October 2007, Helmut Toplizer wrote:
> Hi!
>
> I had similar behavior in the kernel releases since I can think of.
It doesn't happen before 2.6.23.

> (You may find some reports about at
> http://marc.info/?a=113508574400006&r=1&w=2)
>
> Maybe your problem is similar.
>
> Here's what have been found out:
> Plugin of ehci devices causes some strange DMA thing
> which causes delays because of the CPU HLT instruction.
> (DMA are handled with delays on HLT)
>
> Possible fixes:
> 1) Kernel parameter: idle=poll
>     Disables HLT and causes heat up and noise from the cpu
$ cat /proc/cmdline
root=/dev/sdb1 ro vga=794 idle=poll

Same story. 
If I start:
$ while true; do echo test > /dev/null; done
... the transfer rate goes up.

>
> 2) Don't insert EHCI-USB devices
Still reproducable with all USB devices except keyboard+mouse removed, ehci 
deselcted in kernel config and booting with idle=poll.

>
> 3) Patch: attached, try out at your own risk.
>     you need to add a kernel-boot parameter "disableviahlt"
>    (You've got a via-chipset, right?)
>
> Please report back to me if 1/2 works or to linux-ide if the patch works.
No VIA chip in sight. Mainboard is an Intel 975XBX2 and hard disks are 
connected to the ICH7 SATA Controller, so I don't think the patch will help 
me ^^
lspci attached.

Also the transfer rate didn't degrade too much for copying directly from 
reiserfs to reiserfs and not using encfs:

dd if=/mnt/.backup/2CpGkrxvz6wgA0b0xloz8PavzMLrMymOgi9 of=/mnt/.tdata/test
1033+0 records in
1033+0 records out
1083179008 bytes (1.1 GB) copied, 16.9303 s, 64.0 MB/s

Plus the transfer rate doesn't increase if I start a CPU hog while copying 
between reiserfs.

So it looks more to me like theres a bad interaction between the new 
scheduler, fuse and encfs ...


> Thanks
>
> Helmut

Thanks for your reply ^^

View attachment "lspci" of type "text/plain" (18793 bytes)