All of lore.kernel.org
 help / color / mirror / Atom feed
From: Bruno Randolf <br1@einfach.org>
To: Bob Copeland <me@bobcopeland.com>
Cc: Johannes Berg <johannes@sipsolutions.net>,
	Jouni Malinen <j@w1.fi>,
	linville@tuxdriver.com, randy.dunlap@oracle.com,
	peterz@infradead.org, blp@cs.stanford.edu,
	linux-wireless@vger.kernel.org, linux-kernel@vger.kernel.org,
	Lars_Ericsson@telia.com, stefanr@s5r6.in-berlin.de,
	kosaki.motohiro@jp.fujitsu.com, akpm@linux-foundation.org,
	kevin.granade@gmail.com
Subject: Re: [PATCH v7 3/3] nl80211/mac80211: Report signal average
Date: Fri, 19 Nov 2010 18:07:05 +0900	[thread overview]
Message-ID: <201011191807.06013.br1@einfach.org> (raw)
In-Reply-To: <AANLkTimoogSLAipNy=njGtHypqBQSk=usDmXut=KN9TM@mail.gmail.com>

On Thu November 18 2010 08:11:18 Bob Copeland wrote:
> On Wed, Nov 17, 2010 at 11:16 AM, Johannes Berg
> 
> <johannes@sipsolutions.net> wrote:
> > On Wed, 2010-11-17 at 17:28 +0900, Bruno Randolf wrote:
> >> I understand that this could be more efficient, but if it matters or not
> >> - honestly, I don't know. Can a more knowledgeable person than me
> >> comment on this?
> > 
> > Yes, it does matter -- think of an embedded MIPS board running at 500MHz
> > and trying to push 11n speeds.
> 
> I assume the number of samples (weight) is the more
> important tunable.  One option is you can require factor
> to be a power of two that is much larger than weight,
> then at least you can store factor/weight precomputed
> and multiply by it instead of doing a divide in ewma_add.
> Then ewma_get can also just be a shift as well.

Hmm, maybe I suck in mathemathics, but I don't see a way to do that given the 
formula:

(((internal * (weight - 1)) + (val * factor)) / weight

bruno

  parent reply	other threads:[~2010-11-19  9:06 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-11-12  3:00 [PATCH v7 0/3] Generic exponentially weighted moving average (EWMA) Bruno Randolf
2010-11-12  3:00 ` [PATCH v7 1/3] Add generic exponentially weighted moving average (EWMA) function Bruno Randolf
2010-11-12  3:00 ` [PATCH v7 2/3] ath5k: Use generic EWMA library Bruno Randolf
2010-11-12  3:00 ` [PATCH v7 3/3] nl80211/mac80211: Report signal average Bruno Randolf
2010-11-16  9:37   ` Jouni Malinen
2010-11-17  8:28     ` Bruno Randolf
2010-11-17 16:16       ` Johannes Berg
2010-11-17 23:11         ` Bob Copeland
2010-11-19  8:49           ` Bruno Randolf
2010-11-19 14:04             ` Stefan Richter
2010-11-22  2:41               ` Bruno Randolf
2010-11-22  7:26                 ` Stefan Richter
2010-11-19 17:52             ` Johannes Berg
2010-11-22  2:36               ` Bruno Randolf
2010-11-19  9:07           ` Bruno Randolf [this message]
2010-11-19 12:16             ` Peter Zijlstra
2010-11-19 22:28             ` Bob Copeland
2010-11-19 23:01               ` Peter Zijlstra
2010-12-02  8:12                 ` Bruno Randolf
2010-11-19 18:58     ` Johannes Berg
2010-11-22 18:46       ` John W. Linville
2010-11-20 16:45   ` Brian Prodoehl
2010-11-24 16:24   ` Johannes Berg
2010-11-24 19:05     ` Ben Greear

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=201011191807.06013.br1@einfach.org \
    --to=br1@einfach.org \
    --cc=Lars_Ericsson@telia.com \
    --cc=akpm@linux-foundation.org \
    --cc=blp@cs.stanford.edu \
    --cc=j@w1.fi \
    --cc=johannes@sipsolutions.net \
    --cc=kevin.granade@gmail.com \
    --cc=kosaki.motohiro@jp.fujitsu.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-wireless@vger.kernel.org \
    --cc=linville@tuxdriver.com \
    --cc=me@bobcopeland.com \
    --cc=peterz@infradead.org \
    --cc=randy.dunlap@oracle.com \
    --cc=stefanr@s5r6.in-berlin.de \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.