On Tue, Oct 7, 2014 at 5:35 PM, Johannes Berg <johannes@xxxxxxxxxxxxxxxx> wrote: > > On Tue, 2014-10-07 at 13:03 +0200, Stanislaw Gruszka wrote: > > On Mon, Oct 06, 2014 at 05:00:40PM +0200, Johannes Berg wrote: > > > On Wed, 2014-10-01 at 11:27 +0200, Stanislaw Gruszka wrote: > > > > Dynamic power save timeout value is suppose to be configurable via > > > > wext, but due to iwconfig bug is not possible to set using that tool. > > > > > > That's interesting, what's that bug? > > > > https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=532713 > > > > Parsing problem. After reading bug report more detailed I found out it > > is fixed on pre beta version v30, but it was not released i.e. on Fedora > > we use wireless-tools v29. > > Curious. I have version 30 on Debian, but all of this is *years* old. > Hah. > > > > > Allow to configure PS timeout via nl80211 - add NL80211_ATTR_PS_TIMEOUT > > > > attribute which become timeout stated in ms. > > > > > > Why do you want to be able to set it at all though? I remember having > > > this discussion years ago, and we said that it wasn't really useful > > > since the user has no idea when and why this should be changed. I'm not > > > convinced that changed? > > > > > > We had to keep the wext for compatibility - maybe that can now be > > > removed if you say it's broken - but I'm not sure I see much value in > > > adding it (and you're doing nothing to convince me otherwise, so far) > > > > Zdenek (CCed) reported to me 40% download performance degradation when > > PS is used. I think this happen because of delay between packets, but > > it is not confirmed yet (I did not provide patches to Zdenek for > > testing), hence perhaps problem lies somewere else. I can not reproduce > > this issue - I have the same download performance with PS on and off, > > I have quite bad performance when set dynamic PS timeout value less > > than 20ms, with default 100ms things are fine. > > > > I assume we can provide that setting to user space, if it allow to > > fixup performance with PS ? > > I'm not convinced - that'll give you a way to have the bug reporter test > it, or whatever, but that can also be achieved with debugfs or similar, > no? > > "Regular" users will never even get there, they'll either give up on > Linux, the machine, the wifi NIC, or live with the low speeds. They'll > never manipulate things here, and this isn't anything that a userspace > tool could automatically manipulate either. iw/iwconfig tools are not only used by regular users but also used by developers/ engineers. We use it heavily for all our wifi testing, and when debugging performance related issue having a configurable ps timeout is of value. We had to hack the kernel to change that value (did not had enough time to work on iw/iwconfig). So IMHO we need to have this configurable either through iw/mac80211 debugfs. -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
