On 23.02.22 19:08, James Dingwall wrote:
Hi,I have been investigating a very intermittent issue we have with xenstore access hanging. Typically it seems to happen when all domains are stopped prior to a system reboot. xenstore is running in a stubdom and using the hypervisor debug keys indicates the domain is still there.
Could it be dom0 shutdown handling is unloading some modules which are needed for Xenstore communication? E.g. xen-evtchn?
I have come across some old list threads which suggested access via /proc/xen/xenbus could cause problems but it seems patches went in to the kernel for 4.10. However to eliminate this entirely as a possibility I came up with this kernel patch to hide deprecated entries in xenfs.
I don't see how this patch could help. libxenstore is using /dev/xen/xenbus if it is available. So the only case where your patch would avoid accessing /proc/xen/xenbus would be if /dev/xen/xenbus isn't there. But this wouldn't make Xenstore more reactive, I guess. ;-)
I found this old thread for a similar change where the entries were made conditional on kernel config options instead of a module parameter but this was never merged. https://lkml.org/lkml/2015/11/30/761 If this would be a useful feature I would welcome feedback.
I'm not sure how helpful it is to let the user specify a boot parameter for hiding the files. It will probably not get used a lot. Juergen
OpenPGP_0xB0DE9DD628BF132F.asc
Description: OpenPGP public key
OpenPGP_signature
Description: OpenPGP digital signature
