Bug 28880 – ecc support in gentoo-sources (2.4.20-gentoo-r7) doesn't work

• Status: RESOLVED FIXED
• Product: Gentoo Linux

[Description Vadim Trochinsky 2003-09-16 06:45:21 UTC]

The gentoo-source contains a kernel with the ECC patch that allows monitoring of
ECC memory. The line in my .config is:

CONFIG_ECC=y

However, after compiling and booting the kernel, /proc/ram doesn't exist.

Reproducible: Always
Steps to Reproduce:
1. Enable ECC by selecting "ECC memory monitoring" in character devices
2. Build the kernel, install, reboot
3. try to access /proc/ram

Actual Results:  
root@alice linux # uname -a
Linux alice 2.4.20-gentoo-r7 #2 SMP Mon Sep 15 19:28:09 CEST 2003 i686 AMD
Athlon(tm) MP 2000+ AuthenticAMD GNU/Linux
root@alice linux # grep 'CONFIG_ECC' .config
CONFIG_ECC=y
root@alice linux # cat /proc/ram
cat: /proc/ram: No such file or directory
root@alice linux #


Expected Results:  
This is what happens with a properly built ecc module. This was done by
compiling the source from the ecc-linux site and inserting the module:

root@alice linux # cat /proc/ram
Chipset ECC capability : ECC with hardware scrubber
Current ECC mode : ECC with hardware scrubber
Bank    Size    Type    ECC     SBE     MBE
0       256 MB  DDR     scrub   0/0     0/0
1       256 MB  DDR     scrub   0/0     0/0
6       256 MB  DDR     scrub   0/0     0/0
7       256 MB  DDR     scrub   0/0     0/0
Total   1024 MB


Kernel 2.4.20-gentoo-r7 (SMP)
Tyan Tiger MPX motherboard with support for ECC memory
1024MB registered ECC DDR RAM

[Comment 1 Tim Yamin (RETIRED) 2003-10-01 15:03:38 UTC]

Does it work with vanilla 2.4.20?

[Comment 2 Vadim Trochinsky 2003-10-01 15:17:54 UTC]

I think ECC support doesn't exist in vanilla, I'm downloading the source
now to check for sure.

[Comment 3 Vadim Trochinsky 2003-10-01 16:21:19 UTC]

Just checked, ECC support is definitely not available in vanilla, so it's
got to be in a Gentoo patch.

[Comment 4 Tim Yamin (RETIRED) 2004-01-21 08:34:26 UTC]

If you change ecc.c in the kernel sources with the ecc.c available in http://www.anime.net/~goemon/linux-ecc/files/development/ecc-20030225.tgz; does that fix your problem?

[Comment 5 Tim Yamin (RETIRED) 2004-02-10 13:35:06 UTC]

2.4.20-gentoo-r11 has the latest available ECC patch, can you see if that solves this? Thanks!

[Comment 6 Vadim Trochinsky 2004-02-20 13:08:45 UTC]

Sorry for taking so long to reply, got pretty busy here.

How do I get 2.4.20-gentoo-r11? I have up to r9, and then it started downloading 2.4.22, now I have set up linux-2.4.22-gentoo-r7 and linux-2.6.3-gentoo, both of which unfortunately don't seem to have ECC.

Has been the ECC patch dropped for 2.4.22?

[Comment 7 Tim Yamin (RETIRED) 2004-02-20 13:37:17 UTC]

As far as I know it has been dropped from 2.4.22, but I think development on the actual ECC patch has also stopped. Brian, mind adding this in?

Although, this actually looks like it doesn't work because the ECC support is module only or none looking through the source: so I think your best bet is to just try CONFIG_ECC=m before trying out -r13. To get -r13 run an "emerge sync" and do "emerge =gentoo-sources-2.4.20-r13".

[Comment 8 Martin Holzer (RETIRED) 2004-03-23 10:09:41 UTC]

gentoo-sources-2.4.25 is now stable