On Tue, 2011-03-15 at 20:32 -0400, John W. Linville wrote: > On Tue, Mar 15, 2011 at 02:31:59PM -0700, Rick Jones wrote: > > On Tue, 2011-03-15 at 16:51 -0400, John W. Linville wrote: > > > On Tue, Mar 15, 2011 at 09:40:06PM +0200, Jonathan Morton wrote: > > > > > > > > On 15 Mar, 2011, at 8:31 pm, John W. Linville wrote: > > > > > > > > > If you don't throttle _both_ > > > > > the _enqueue_ and the _dequeue_, then you could be keeping a nice, > > > > > near-empty tx queue on the host and still have a long, bloated queue > > > > > building at the device. > > > > > > > > Don't devices at least let you query how full their queue is? > > > > > > I suppose it depends on what you mean? Presumably drivers know that, > > > or at least can figure it out. The accuracy of that might depend on > > > the exact mechanism, how often the tx rings are replinished, etc. > > > > > > However, I'm not aware of any API that would let something in the > > > stack (e.g. a qdisc) query the device driver for the current device > > > queue depth. At least, I don't think Linux has one -- do other > > > kernels/stacks provide that? > > > > HP-UX's lanadmin (and I presume the nwmgr command in 11.31) command will > > display the "classic" interface MIB stats, which includes the outbound > > queue length. What it does (or should do) for that statistic in the > > face of a multi-queue device I've no idea :) > > But that is capacity, right? Not current occupancy? I thought that > was the outcome of an earlier thread?
No, HP-UX shows current occupancy on its interfaces. I think it is Cisco which shows capacity - at least that is my recollection of one of the other discussions. rick _______________________________________________ Bloat mailing list [email protected] https://lists.bufferbloat.net/listinfo/bloat
