On Wed, Jun 06, 2012 at 09:54:01PM +0200, Eric Dumazet wrote: > On Wed, 2012-06-06 at 21:51 +0300, Michael S. Tsirkin wrote: > > > BTW for cards that do implement the counters in software, > > under xmit lock, is anything wrong with simply taking the xmit lock > > when we get the stats instead of the per-cpu trick + seqlock? > > > > I still dont understand why you would do that. > > Most modern machines are 64bits, so there is no seqlock overhead, > nothing at all. > > If you focus on 32bit hardware, just stick on 32bit counters ? These wrap around. > Note that most u64_stats_sync users are virtual drivers, without xmit > lock (LLTX drivers) > > Absolutely, I am talking about virtio here. I'm not kicking u64_stats_sync idea I am just saying that simple locking would work for virtio and might be better as it gives us a way to get counters atomically. -- MST _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization
