Comment 11 for bug 337419

This performance regression saga continues....

I installed Ubuntu Lucid Lynx rc2 which is based on 2.6.32-something. The performance is as expected (89/90MB/s) doing my simple dd test.

I downloaded 2.6.32.7 from kernel.org and compiled a kernel using the Ubuntu config file as a starting point (added bnx driver as compiled in rather than a module and enabled sysfs deprecated support).

I installed the resulting .deb and booted up (ignoring the sysfs warning...). My dd test (on the Lucid Lynx system running my 2.6.32.7 kernel) gave around 90MB/s - so performance is as expected.

I copied the compiled .deb to a Ubuntu 8.04 system and installed it. The dd test (on the Hardy Heron system running the same 2.6.32.7 kernel as above) gave around 21MB/s.

I have performed these tests on two different HP DL360G5s just incase there is some oddity with the hardware.

So based on this new information, I am now not 100% sure that the performance regression lies with the cciss driver itself, but could perhaps be a result of some kernel parameters that the Ubuntu distribution tweaks.

I compared the hardy and lucid based systems' sysctl, /proc/sys and /sys parameters. Nothing in there jumped out as being obviously related to this issue.

I am still at a loss and really wish I could get 2.6.32 running on a Hardy based Ubuntu system with decent cciss driver performance.