On Thu, Jan 31, 2008 at 02:21:58PM -0800, Christoph Lameter wrote: > Is this okay for KVM too?
->release isn't implemented at all in KVM, only the list_del generates complications. I think current code could be already safe through the mm_count pin, becasue KVM relies on the fact anybody pinning through mm_count like KVM does, is forbidden to call unregister and it's forced to wait the auto-disarming when mm_users hits zero, but I feel like something's still wrong if I think that I'm not using call_rcu to free the notifier (OTOH we agreed the list had to be frozen and w/o readers (modulo _release) before _release is called, so if this initial assumption is ok it seems I may be safe w/o call_rcu?). But it's really tricky path. Anyway this is the last of my worries right now, it works perfectly fine with a single user obviously, and the moment KVM threads runs remotely through GRU/XPMEM isn't happening too soon ;) so let's concentrate on the rest first. I can say hlist_del_init doesn't seem to provide any benefit given nobody could possibly decide to call register or unregister after _release run. ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ _______________________________________________ kvm-devel mailing list kvm-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/kvm-devel
