Return-path: Received: from mail-lf0-f52.google.com ([209.85.215.52]:35265 "EHLO mail-lf0-f52.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751499AbcBGH1k (ORCPT ); Sun, 7 Feb 2016 02:27:40 -0500 Received: by mail-lf0-f52.google.com with SMTP id l143so79454649lfe.2 for ; Sat, 06 Feb 2016 23:27:39 -0800 (PST) MIME-Version: 1.0 In-Reply-To: <87k2mhro8j.fsf@purkki.adurom.net> References: <87k2mhro8j.fsf@purkki.adurom.net> Date: Sun, 7 Feb 2016 09:27:38 +0200 Message-ID: (sfid-20160207_082742_958340_01E42B78) Subject: Re: Monitor interface TX performance boost From: Emmanuel Grumbach To: Kalle Valo Cc: Nikolay Martynov , linux-wireless Content-Type: text/plain; charset=UTF-8 Sender: linux-wireless-owner@vger.kernel.org List-ID: On Sun, Feb 7, 2016 at 9:09 AM, Kalle Valo wrote: > Nikolay Martynov writes: > >> I'm seeing strange behavior on my intel 6300 card. >> >> If I measure TX performance just after boot (iperf in tcp mode), I get this: >> >> [ 3] 0.0-10.1 sec 11.2 MBytes 9.32 Mbits/sec >> >> But if create and enable monitor interface (with command like 'sudo >> iw phy phy0 interface add moni0 type monitor && sudo ifconfig moni0 >> up') I get this: >> >> [ 3] 0.0-10.1 sec 34.8 MBytes 29.0 Mbits/sec >> >> That's about three times boost in throughput by just creating an >> interface (without even using it). >> Doing 'ifconfig moni0 down' bring performance back to 10Mbits range. >> >> Experiments are done with laptop being ~5m from router and not moving. >> These results are repeatable, i.e. not caused by random things like >> other stations transmitting, or channel being busy. >> >> Is this something expected? Is there any reason performance can be as >> good without monitor interface existing? > > Maybe the monitor mode disables power save automatically? > That could be an option although I remember to have disabled power save by default (cough..). That happened in 3.17 IIRC.