Hi Nathan, Nathan Fontenot <nf...@linux.vnet.ibm.com> writes: > On 08/08/2018 10:29 AM, John Allen wrote: >> While handling PRRN events, the time to handle the actual hotplug events >> dwarfs the time it takes to perform the device tree updates and queue the >> hotplug events. In the case that PRRN events are being queued continuously, >> hotplug events have been observed to be queued faster than the kernel can >> actually handle them. This patch avoids the problem by waiting for a >> hotplug request to complete before queueing more hotplug events. >> >> Signed-off-by: John Allen <jal...@linux.ibm.com> > > In the V2 thread it was mentioned that we could just call the DLPAR operation > directly instead of going through the workqueue. I have written a patch to do > this that also cleans up some of the request handling. > > requests that come through the hotplug interrupt still use the workqueue. The > other requests, PRRN and sysfs, just call the dlpar handler directly. This > eliminates the need for a wait conditional and return code handling in the > workqueue handler and should solve the issue that John solves with his patch. > > This still needs testing but wanted to get people's thoughts.
It looks great to me. I guess I thought we'd need to add a lock, but I think you're right that the existing device hotplug lock will work. So if this survives a bit of testing then I'd love to merge it. cheers
