On Thu, 14 Jan 2010 01:47:53 pm Amit Shah wrote: > On (Thu) Jan 14 2010 [09:45:12], Rusty Russell wrote: > > On Wed, 13 Jan 2010 09:54:52 pm Amit Shah wrote: > > > On (Wed) Jan 13 2010 [21:43:32], Rusty Russell wrote: > > > > On Wed, 13 Jan 2010 04:41:48 pm Amit Shah wrote: > > > > > On (Mon) Jan 04 2010 [15:17:17], Amit Shah wrote: > > > > > > On (Mon) Jan 04 2010 [19:45:30], Rusty Russell wrote: > > > > > > > On Wed, 23 Dec 2009 01:04:28 am Amit Shah wrote: > > > > > > > > The console could be flooded with data from the host; handle > > > > > > > > this > > > > > > > > situation by buffering the data. > > > > > > > > > > > > > > Is this still true? If we only add_buf when we're ready, surely > > > > > > > the host > > > > > > > can't flood us with one virtqueue per port? > > > > > > > > > > > > I guess I meant something completely different. This message is > > > > > > definitely misleading and I'll re-word it. > > > > > > > > > > > > You're right; we don't need the 'guest throttling' feature that was > > > > > > needed earlier. > > > > > > > > > > BTW I meant this series doesn't have the guest throttling feature. > > > > > > > > > > Rusty, did you just have this comment for the series? If yes, I'll > > > > > just > > > > > re-send this patch with a fixed description. > > > > > > > > I don't see why we ever allocate more than one incoming buffer though? > > > > > > To prevent against a fast host app sending data to a slow guest > > > consumer. > > > > > > Also, we use the in_vq for the buffering, so the number of buffers is > > > limited by the queue size that's declared by the host. > > > > But if the guest only ever registers one input buffer at a time, we get the > > same effect. And it means we use less memory. And our code is simpler. > > The number of buffers to be registered in the vq comes from the host > anyway; if the host wants to be able to use multiple buffers, we should > be able to use them.
I have sympathy with this, but I'd prefer to see the minimal solution first and look at this later. A single buffer should make for simpler code... > Also, we lose out on the ability of the host to send us data when the > guest is slow to read. That happens at some point anyway. Thanks, Rusty. _______________________________________________ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linux-foundation.org/mailman/listinfo/virtualization
