Return-path: Received: from mout3.freenet.de ([195.4.92.93]:47339 "EHLO mout3.freenet.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750834Ab3AQLn6 (ORCPT ); Thu, 17 Jan 2013 06:43:58 -0500 Date: Thu, 17 Jan 2013 12:25:04 +0100 From: Andreas Hartmann To: Stanislaw Gruszka Cc: linux-wireless@vger.kernel.org, Seth Forshee , Paul Stewart , Amitkumar Karwar , Bing Zhao Subject: Re: [RFC] mac80211: soft scan vs latency Message-ID: <20130117122504.1bf51f82@dualc.maya.org> (sfid-20130117_124404_116951_831777D9) In-Reply-To: <20130116140102.GA10746@redhat.com> References: <20130114145558.GA24250@redhat.com> <20130116140102.GA10746@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Sender: linux-wireless-owner@vger.kernel.org List-ID: On Wed, 16 Jan 2013 15:01:02 +0100 Stanislaw Gruszka wrote: > On Mon, Jan 14, 2013 at 03:55:58PM +0100, Stanislaw Gruszka wrote: > > Except latency, patch perhaps also improve throughput, since we > > spend more time on-channel while scanning. But I'm not quite sure, > > since overall scanning time is bigger. I did not test influence of > > the patch on throughput. > > > > I tested patch by doing: > > > > while true; do iw dev wlan0 scan; sleep 3; done > /dev/null > > I can see slight throughput improvement with patch, measured by scp: > > Upload to periodical scanning machine: > scp -B Fedora-18-Beta-i686-Live-Desktop.iso stasiu@192.168.1.105:~/ > > Unpatched: 3.9MB/s 03:15 > Patched: 4.3MB/s 02:58 W/o any scan? > Download from periodical scanning machine: > scp -B stasiu@192.168.1.105:~/Fedora-18-Beta-i686-Live-Desktop.iso . > > Unpatched: 5.5MB/s 02:17 > Patched: 6.2MB/s 02:02 W/o any scan? I saw this problem some days ago, too. And: You are right. Using realtime applications is quite unusable with stock sw-stack. That's one reason amongst others why I don't use networkmanager at all, but solely wpa_supplicant and managed dhcpcd via wpa_supplicant logfile while starting. But this is not the only point, which breaks realtime applications. Another one is rekeying (4 way handshake), which is broken when executed while network load. Kind regards, Andreas Hartmann