On Thu, May 23, 2013 at 01:26:33PM -0400, Luiz Capitulino wrote: > On Thu, 23 May 2013 20:18:34 +0300 > "Michael S. Tsirkin" <m...@redhat.com> wrote: > > > On Thu, May 23, 2013 at 11:54:03AM -0400, Luiz Capitulino wrote: > > > On Thu, 16 May 2013 18:17:23 +0300 > > > "Michael S. Tsirkin" <m...@redhat.com> wrote: > > > > > > > > The > > > > > existing throttling approach ensures that if the event includes latest > > > > > guest information, then the host doesn't even have to do do a query, > > > > > and > > > > > is guaranteed that reacting to the final event will always see the > > > > > most > > > > > recent request. But most importantly, if the existing throttling > > > > > works, > > > > > why do we have to invent a one-off approach for this event instead of > > > > > reusing existing code? > > > > > > Sorry to restart this week old discussion, but I'm now reviewing the patch > > > in question and I dislike how we're coupling the event and the query > > > command. > > > > > > > Because of the 1st issue above. A large delay because we > > > > > > Has this been measured? How long is this large delay? > > > > > > Also, is it impossible for management to issue query-rx-filter > > > on a reasonable rate that would also cause the same problems? > > > IOW, how can we be sure we're fixing anything without trying it > > > on a real use-case scenario? > > > > Play with priorities, you can make management arbitrarily slow. It's > > just not sane to assume any timing guarantees for tasks running on > > Linux. > > Would you mind to elaborate? I'm not sure I understand how this answers > my questions.
Maybe I don't understand the questions. You are asking why doesn't usual throttling sufficient? This was discussed in this thread already. That's because it would introduce a huge delay if guest changes the mac too often. People don't except that changing a mac is a thing the should do slowly. Event throttling was not designed for events where guest asks management to do something. -- MST
