From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from xc.sipsolutions.net ([83.246.72.84]:39256 "EHLO sipsolutions.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751583AbYIKKzH (ORCPT ); Thu, 11 Sep 2008 06:55:07 -0400 Subject: Re: sta_info->fail_avg From: Johannes Berg To: Javier Cardona Cc: Luis Carlos Cobo , linux-wireless In-Reply-To: <445f43ac0809102215w2637dff7sa2c60dd8c31ccf6@mail.gmail.com> (sfid-20080911_071515_093032_4655B850) References: <1221091198.3804.55.camel@johannes.berg> <445f43ac0809102215w2637dff7sa2c60dd8c31ccf6@mail.gmail.com> (sfid-20080911_071515_093032_4655B850) Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="=-TrBhvBSf3zNjd8Nyuqhf" Date: Thu, 11 Sep 2008 12:54:31 +0200 Message-Id: <1221130471.6986.15.camel@johannes.berg> (sfid-20080911_125513_326280_BA2DCE2C) Mime-Version: 1.0 Sender: linux-wireless-owner@vger.kernel.org List-ID: --=-TrBhvBSf3zNjd8Nyuqhf Content-Type: text/plain Content-Transfer-Encoding: quoted-printable Javier, > It is used to estimate the average retransmissions that will be > required to send a nominal frame over a given peer link. > That's one component of the airtime link metric. Ok. > > I do know that neither ath9k's nor Intel's rate > > control algorithms ever set it so it'll always be zero. >=20 > In that case transmission failures will not be taken into account and > nodes with that hardware will report a lower (better) link metric than > what they should. In other words, those nodes will attract mesh > traffic, which will provide a strong incentive for the driver > maintainers to set that value correctly :) Heh, ok. I've been trying to reduce the amount of stuff the rate control algorithm needs to do, does this need to be in the rate control algorithm? It seems that the we simply calculate pf =3D spinfo->tx_num_failed * 100 / spinfo->tx_num_xmit; and fail_avg =3D ((pf + (spinfo->last_pf << 3)) / 9); (in a fixed-point format that has more precision) and we could do all that in the generic code if we get proper information from the driver. Anyway, for now I'll leave it as-is. johannes --=-TrBhvBSf3zNjd8Nyuqhf Content-Type: application/pgp-signature; name=signature.asc Content-Description: This is a digitally signed message part -----BEGIN PGP SIGNATURE----- Comment: Johannes Berg (powerbook) iQIcBAABAgAGBQJIyPjkAAoJEKVg1VMiehFY/+YP/0EY/aNAcdEhScGPqOkqNpcW 3yOv9USGNHIpuipVqQz4eIwkFBClLtwIxyzgioCAXjhQLDryaPr8oth8v7ILxjzC F8NkdKVt5Dz+3bZFTtdTdawVFwZJUzs4sXr3O7XP9VzK/QfDawhbViCuQccmC9BT wyAVGh3F4cR9mrfzC5efqETKsrTwGYmSc5ZDT6fEWo6wilMEmdLJoiukHRg6+5my xV2DqnrH1OXwYtUbmkO5I3Fx2Ez7LPq2Z2iS6PzcnbdG/hakxuBg2qbz80ghgCD0 CCdq/56XVtpv8BYN7eXI6N7j5WPPPHrdT3nu0lpsXziXVEjrNvWob0Wp52McPlJ/ k0ss1DX7nJL0QCCPaJpt/q+AjaIaZ3jkUyOyLQdWL5vPP0tegmWlu7RLOLpTA7Gp bpVPqNM3eOjalUNdJ1uQpaE4xgRMzNIB3QZxE1y1zm9wAuPirr9AAfKhVtxniJsd T242ViCU8lOhAYoTipdB7/TdL7hs1lJHlrqHBgrMWffos7cKL6woj7a5HXbgpt37 AskOoGmxrq/WqOlVUwiWzhYkg7VzKI5qcra01MW7RVVmY2psQLkyIan0mlp6TMj9 OjtJo+97PV0kldmG343oBZkML9M41i0Ozx18nE4XdqpkoTOvLh5jJVMHaGISbPO4 2IF086ebXznYYV0zdPaW =Rugb -----END PGP SIGNATURE----- --=-TrBhvBSf3zNjd8Nyuqhf--