Re: [libvirt] [PATCH] qemu: Refresh capabilities when creating resctrl allocation

On Fri, Feb 02, 2018 at 12:44:03 +0100, Martin Kletzander wrote: > Since one of the things in capabilities (info from resctrl updated with data > about caches) can be change on the system by remounting the /sys/fs/resctrl with > different options, the capabilities need to be refreshed. There is a better fix > in the works, but it's going to be way bigger than this (hence the XXX note > there), so for the time being let's workaround this. And in order not to slow > down the domain starting, only get the capabilities if there are any cachetunes. > > Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1540780 This BZ describes a crash if the filesystem is remounted, but you are attempting to fix this not by fixing the code that crashed but by re-loading the information if possibly somebody remounted it. This does not seem to be the correct fix since you still have a race window, where the options can be changed after the refresh is executed and prior to using them in the code where it actually crashed.