From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from smtp.nokia.com ([192.100.122.230]:35217 "EHLO mgw-mx03.nokia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751059Ab0DMJOK (ORCPT ); Tue, 13 Apr 2010 05:14:10 -0400 Subject: Re: [RFC PATCH] nl80211: Add support for dynamic ps timeout configuration From: Juuso Oikarinen To: ext Kalle Valo Cc: ext Johannes Berg , "linux-wireless@vger.kernel.org" , "Ylalehto Janne (Nokia-D/Tampere)" In-Reply-To: <87sk6zoh4x.fsf@purkki.valot.fi> References: <1271059902-27788-1-git-send-email-juuso.oikarinen@nokia.com> <1271061120.3877.6.camel@jlt3.sipsolutions.net> <1271062589.10120.1169.camel@wimaxnb.nmp.nokia.com> <1271063175.3877.13.camel@jlt3.sipsolutions.net> <1271065535.10120.1191.camel@wimaxnb.nmp.nokia.com> <871vekpexo.fsf@purkki.valot.fi> <1271143746.10120.1232.camel@wimaxnb.nmp.nokia.com> <87wrwboirr.fsf@purkki.valot.fi> <1271148573.10120.1257.camel@wimaxnb.nmp.nokia.com> <87sk6zoh4x.fsf@purkki.valot.fi> Content-Type: text/plain; charset="UTF-8" Date: Tue, 13 Apr 2010 12:10:02 +0300 Message-ID: <1271149802.10120.1262.camel@wimaxnb.nmp.nokia.com> Mime-Version: 1.0 Sender: linux-wireless-owner@vger.kernel.org List-ID: On Tue, 2010-04-13 at 11:07 +0200, ext Kalle Valo wrote: > Juuso Oikarinen writes: > > >> > The problem here is that the latency at least cannot be used in any > >> > simple and/or general way I can think of to control the dynamic PS > >> > timeout. > >> > >> Can't you do something like this: > >> > >> pm_qos >= 1000 -> timeout 0 ms (aka. full power save) > >> pm_qos <= 100 -> timeout 100 ms > >> pm_qos <= 50 -> timeout 300 ms > >> > >> That is, just some arbitrary numbers but which affect dynamic ps > >> timeout. I haven't thought about the numbers at all, but they actually > >> don't matter because it's easy to change them inside mac80211. > > > > Theoretically I could, but I'm pretty sure whatever values I would > > choose would be unacceptable by others, as they would be tuned for a > > specific use. > > I don't see a problem with that. The current use of pm_qos is very > limited, I think it's all positive if we start using it more. > > > Also, although AFAIK barely anyone uses the DTIM interval which is > > determined based on th pm_qos, adding arbitrary rules like this to the > > side risks breaking something for someone. > > AFAIK the pm_qos values are not set in stone in any. Applications just > request something and kernel can do whatever it wants, even ignore it. > So I don't see any harm if we change how mac80211 uses pm_qos values. > And most probably this will change many times in the future. > Ok, you convinced me. I will send a RFC patch with the above, and will sub-sequentially be flamed to death ;) Be sure to look into that bug in wl1251 at some point, so I don't break it with this, if by chance I get this to go through ;) -Juuso