From mboxrd@z Thu Jan 1 00:00:00 1970 From: Patrick McHardy Subject: Re: SFQ: Reordering? Date: Sat, 07 May 2005 00:07:42 +0200 Message-ID: <427BEAAE.409@trash.net> References: <7bca1cb5050506145344d16b1e@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: netdev@oss.sgi.com Return-path: To: Asim Shankar In-Reply-To: <7bca1cb5050506145344d16b1e@mail.gmail.com> Sender: netdev-bounce@oss.sgi.com Errors-to: netdev-bounce@oss.sgi.com List-Id: netdev.vger.kernel.org Asim Shankar wrote: > Hi, > > I was looking through sch_sfq.c. From what I could make out, if the > perturbation period is non-zero (say Xseconds), then ever X seconds, > sfq_perturbation() is invoked. This changes the perturbation value > that will be used by the hash function, however, packets already > existing in the queue aren't rehashed. > > As a result, new packets being enqueued will have a different hash > value and thus packet re-ordering will take place. I ran a quick test > using netperf and tcpdump and seem to notice this re-ordering. > > Should complete rehashing take place in sfq_perturbation(), or am I > missing something? (I was looking at 2.6.9 and also took a cursory > glance at 2.6.11 on lxr.linux.no) I think we should rehash. Can you send a patch? Regards Patrick