Preliminary observations 2.6.1 kernels both 32 and 64 bit on Cobalt Mips Qube
Hi there,
I?ve had some time to pull down some of the latest development kernels for
the r5K cobalt machines to see how they work. I?ve tried Martin M?s 2.6.15
kernel as well as Aurelien J?s 2.6 DMA kernel and the 64bit kernel. I ran
some simple SFTP transfers to measure performance differences and have been
using the 64bit kernel with samba for network disk archivals for the last
few days. Here?s my observations:
1) All in all the system is stable. I?ve not had any crashes or unexpected
issues with the server after installing any of the OS?. In general, I sense
the 32bit DMA enabled kernel runs a little faster than the 64 bit, but as
you can see from the notes below, its not dramatic. This may be due to
installation issues (pilot error), machine limitations, or application
issues. What I found both interesting and discouraging was that when I was
archiving PCs through samba, my ssh session to the Qube was REALLY SLOW. It
almost looked like tty-ing through a 300 baud modem.
2) to put the following data in context, here?s some important background
information on the Qube and its setup:
Model: 2700 workgroup Qube r5K headless (ugh!) 64MB ram 300GB Seagate drive:
Initial configuration: Martin M?s 2.4 tarball installed through a host
Upgraded to 2.6 kernel through /~tbm/mips-2.6 kernel then tested
Upgraded to 2.6 dma kernel with downloaded image and dpkg ?i
Upgraded to 2.6 64bit kernel with downloaded image and dpkg ?i
2.4 kernel networked with 10Mb on board interface (tulip)
2.6 kernels networked with VIA-rhine 100Mb adapter (tulip wouldn?t work. see
below)
Note: no tuning nor recompiling between tests. Using original installed
modules
Now?Finally, some stats on sftp performance:
under 2.4.m memory available is 62264* net i/o performance is 450KB/sec on
10Mb
under 2.6.m memory available is 61816* net i/o performance is 412KB/sec on
100Mb
under 2.6.j 32bit memory available is 61732* i/o performance is 441KB/sec on
100Mb
under 2.6.j 64bit memory available is 60468* i/o performance is 410KB/sec on
100Mb
*The total available memory is reported through top.
SFTP was performed with a 675MB iso image.
The discrepancy in nic adapter is because I didn?t have a loadable module
for the 100Mb adapter under 2.4.
I was unable to get the on board tulip driver to work under any of the
2.6 kernels. The nic would get an ip address from the dhcp server and would
respond to a ping but it wouldn?t do anything else. I suspect the interface
isn?t being initialized properly because Its Mac address is ff:ff:ff:ff:ff
(see message logs for precise info). The problem was consistent Across all
2.6 kernels regardless of whether the 100Mb nic was installed or not.
Here are links to the dmesg and messages logs of the kernels used in the
tests:
http://home.comcast.net/~michaelfrancini/2.6.dma.dmesg
http://home.comcast.net/~michaelfrancini/2.6.dma.messages
http://home.comcast.net/~michaelfrancini/64dmesg
http://home.comcast.net/~michaelfrancini/64messages
http://home.comcast.net/~michaelfrancini/2.4.dmesg
http://home.comcast.net/~michaelfrancini/2.4.messages
http://home.comcast.net/~michaelfrancini/2.6.messages
http://home.comcast.net/~michaelfrancini/dmesg.2.6
I welcome any suggestions, comments, corrections or additional tests. If I
can do it, I will.
Best, and thanks for all the great work!!
Mike F.
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