From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail2.tohojo.dk (mail2.tohojo.dk [77.235.48.147]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.bufferbloat.net (Postfix) with ESMTPS id 0D1623B260 for ; Fri, 30 Sep 2016 08:41:45 -0400 (EDT) X-Virus-Scanned: amavisd-new at mail2.tohojo.dk DKIM-Filter: OpenDKIM Filter v2.10.3 mail2.tohojo.dk 5083B41622 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=toke.dk; s=201310; t=1475239303; bh=Ux7CExSYaGLcYqJ/zzlfNP/Fpzg34AvS+6FMTpbtjKA=; h=From:To:Cc:Subject:References:Date:In-Reply-To:From; b=OzkFsMeaazdrQjTY7pYznETbqffdB+KF+cCQx8MMTAsZeNlTnaHAu0CalRSCf2cUm Ig+118nHrjyzaKtaAjea7Jjd3L/+kYfr/Spp8duO/8WVZy/kjnGPHXnPVoRAwHBXur 3fTCqtgOzZpjOnhu+Euxrr6kqqLVGAHulxq/0Q9s= Sender: toke@toke.dk Received: by alrua-kau.kau.toke.dk (Postfix, from userid 1000) id 730DEC4024B; Fri, 30 Sep 2016 14:41:42 +0200 (CEST) From: =?utf-8?Q?Toke_H=C3=B8iland-J=C3=B8rgensen?= To: Johannes Berg Cc: make-wifi-fast@lists.bufferbloat.net, linux-wireless@vger.kernel.org, netdev@vger.kernel.org References: <20160923195911.4572-1-toke@toke.dk> <20160923195911.4572-4-toke@toke.dk> <1475235230.17481.43.camel@sipsolutions.net> Date: Fri, 30 Sep 2016 14:41:42 +0200 In-Reply-To: <1475235230.17481.43.camel@sipsolutions.net> (Johannes Berg's message of "Fri, 30 Sep 2016 13:33:50 +0200") X-Clacks-Overhead: GNU Terry Pratchett Message-ID: <87twcx5zll.fsf@toke.dk> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Subject: Re: [Make-wifi-fast] [PATCH 3/3] mac80211: Set lower memory limit for non-VHT devices X-BeenThere: make-wifi-fast@lists.bufferbloat.net X-Mailman-Version: 2.1.20 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 30 Sep 2016 12:41:45 -0000 Johannes Berg writes: > On Fri, 2016-09-23 at 21:59 +0200, Toke H=C3=B8iland-J=C3=B8rgensen wrote: >> Small devices can run out of memory from queueing too many packets. >> If VHT is not supported by the PHY, having more than 4 MBytes of >> total queue in the TXQ intermediate queues is not needed, and so we >> can safely limit the memory usage in these cases and avoid OOM. > > I kinda see the logic here - we really don't need to queue as much if > we can't possibly transmit it out quickly - but it seems to me we > should also throw in some kind of limit that's relative to the amount > of memory you have on the system? Yes, ideally. That goes for FQ-CoDel as well, BTW. LEDE currently carries a patch for that which just changes the hard-coded default to another hard-coded default. Not sure how to get a good value to use, though; and deciding on how large a fraction of memory to use for packets starts smelling an awful lot like setting policy in the kernel, doesn't it? > I've applied these anyway though. I just don't like your assumption (b) > much as the rationale for it. Right, thanks. I'll come up with a better rationale next time ;) -Toke