[openib-general] Re: performance counters in /sys

[Grant Grundler]

On Sun, May 22, 2005 at 08:33:51AM +0300, Michael S. Tsirkin wrote:
> > That's good, IMHO.
> 
> It will also prevent hotplug from working. So no, I dont think its good.

I agree that hotplug should work. 
I'm just pointing out that keeping the file open should
prevent the driver from unloading.

> > Unloading the HCA driver will disable the device.
> > On ia64 platforms (and probably PPC too) will lead to hard fail on the
> > next MMIO read since the device won't respond to MMIO space accesses.
> > 
> > "lsof /sys/class/infiniband" would help track down the monitoring tool.
> 
> Who would do MMIO reads if the driver is unloaded?

No one if the /sys file was closed like we want them too.
I'm just pointing out the counters must point at an enabled device
for as long as any one of the /sys files was open.

thanks,
grant