From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [RFC PATCH 2/3] [TCP]: Reordered ACK's (old) SACKs not included to discarded MIB Date: Tue, 25 Sep 2007 22:47:11 -0700 (PDT) Message-ID: <20070925.224711.26514452.davem@davemloft.net> References: <11906246483472-git-send-email-ilpo.jarvinen@helsinki.fi> <11906246483657-git-send-email-ilpo.jarvinen@helsinki.fi> <11906246484144-git-send-email-ilpo.jarvinen@helsinki.fi> Mime-Version: 1.0 Content-Type: Text/Plain; charset=iso-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: netdev@vger.kernel.org To: ilpo.jarvinen@helsinki.fi Return-path: Received: from 74-93-104-97-Washington.hfc.comcastbusiness.net ([74.93.104.97]:50312 "EHLO sunset.davemloft.net" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1751986AbXIZFrL convert rfc822-to-8bit (ORCPT ); Wed, 26 Sep 2007 01:47:11 -0400 In-Reply-To: <11906246484144-git-send-email-ilpo.jarvinen@helsinki.fi> Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org =46rom: "Ilpo_J=E4rvinen" Date: Mon, 24 Sep 2007 12:04:07 +0300 > In case of ACK reordering, the SACK block might be valid in it's > time but is already obsoleted since we've received another kind > of confirmation about arrival of the segments through snd_una > advancement of an earlier packet. >=20 > I didn't bother to build distinguishing of valid and invalid > SACK blocks but simply made reordered SACK blocks that are too > old always not counted regardless of their "real" validity which > could be determined by using the ack field of the reordered > packet (won't be significant IMHO). >=20 > DSACKs can very well be considered useful even in this situation, > so won't do any of this for them. >=20 > Signed-off-by: Ilpo J=E4rvinen This looks fine to me, applied. If the skipped case is interesting we can add another MIB stat for it :-)