Kernel 2.6.31 is out and rocking!

This weekend I’ve had some free time so I tested a new kernel on my suse 11.1 x86_64 system. I’ve been a beta tester for the kernel for some time and I was eager to test the final version.

There are plenty new features, the one I enjoy more are probably on the filesystem area but there is plenty to choose.

This version adds USB 3.0 support, a equivalent of FUSE for character devices used for proxying OSS sound to ALSA, some memory management changes that improve interactivity in desktops, readahead improvements, ATI Radeon Modesetting support, support for Intel’s Wireless Multicomm 3200 Wifi devices, kernel support and a userspace tool for performance counters, gcov support, a memory checker for unitialized memory, a memory leak detector, a reimplementation of inotify and dnotify on top of a new filesystem notification infrastructure, btrfs improvements, support for the IEEE 802.15.4 network standard, IPv4 over Firewire, many new drivers, small improvements and fixes.

You may see the hole list here:

http://kernelnewbies.org/Linux_2_6_31

I still didn’t do extensive testing but so far so good ;), although my kde4.3  seams to lag a bit, I’m not sure if this is from the new kernel or the changes I’ve done within KDE itself.

On the other end with server machines it works perfectly, i’m doing stress tests on two virtual servers and memory usage / IO times / CPU usage.

On the test i’m using two opensuse 11.1 x86_64, one as 2.6.27 kernel version and the other 2.6.31, same amount of memory and 2 cpu each on the same host. Hope to have some more data in a few days and then post the results (cacti graphs) here if they are relevant.

So, what are you waiting for… TRY IT

Cheers

Pedro Oliveira

Linux support?

From sometime now I’ve been working on debugging  software, I don’ mind using betas (with all the inherent pain), as a matter of fact I like it a lot. But recently I had a problem with my MERLIN U740 PCMCIA card (it’s a 3G modem). This card emulates two USB ports and in one there’s the modem. This as been working for year without problems but since the kernel 2.6.24 it stopped working in x86_64. I didn’t care that much as i was working out of the country and didn’t use the card. But now I need to use it so I posted a bug report in OpenSuSE (the distro i use) and I’ve been testing their output on this bug. Finally its solved in the kernel 2.6.31 (from the release candidate 3) and it will be included in the main stream OpenSuSE distribution 11.2 (it’s already included in the factory version).

The bug I’m talking about is described in:

https://bugzilla.novell.com/show_bug.cgi?id=502557

and it’s about the following kernel messages:

USB HC takeover failed!  (BIOS/SMM bug)

So in the end i can say I’m pretty happy with Linux support, and this kind of support is available to open source distros, not only to enterprise level distributions such as SLES or RHE. Just keep on filling those bugs reports when you find one.
Cheers,
Pedro Oliveira

SD card lock switch causing problems

Yesterday while working i needed to tranfer some file to a sd card. This is a simple task, trivial thing to do but i was having trouble doing it. My card reader refused to read my SD card, no matter what i did, started looking at logs, dmesg and so on. after a while without significant info found i tried the card on a friends lap and it worked without a itch.

The only thing that showed up in var log messages was:

Jun 23 19:17:43 martini-lap kernel: sd 7:0:0:0: [sdb] Unhandled sense code
Jun 23 19:17:43 martini-lap kernel: sd 7:0:0:0: [sdb] Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE
Jun 23 19:17:43 martini-lap kernel: sd 7:0:0:0: [sdb] Sense Key : Medium Error [current]
Jun 23 19:17:43 martini-lap kernel: sd 7:0:0:0: [sdb] Add. Sense: Unrecovered read error
Jun 23 19:17:43 martini-lap kernel: end_request: I/O error, dev sdb, sector 0
Jun 23 19:17:43 martini-lap kernel: Buffer I/O error on device sdb, logical block 0
Jun 23 19:17:43 martini-lap kernel: Buffer I/O error on device sdb, logical block 1
Jun 23 19:17:43 martini-lap kernel: Buffer I/O error on device sdb, logical block 2
Jun 23 19:17:43 martini-lap kernel: Buffer I/O error on device sdb, logical block 3

well the prob was the tiny switch on the SD card that allows you to lock on read only mode. The card was lacking the switch, with some adesive tape it was fixed. The strange thing is that it worked on my friends lap. Maybe it’s lap doesn’t check for the lock switch.

Hope this may help someone out there with the same prob.

Cheers.

Pedro