From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp1-g21.free.fr (smtp1-g21.free.fr [IPv6:2a01:e0c:1:1599::10]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by huchra.bufferbloat.net (Postfix) with ESMTPS id E23EC21F352 for ; Sun, 21 Jun 2015 08:04:55 -0700 (PDT) Received: from pirx.pps.univ-paris-diderot.fr (unknown [78.194.40.74]) by smtp1-g21.free.fr (Postfix) with ESMTPS id D4F08940063; Sun, 21 Jun 2015 17:04:50 +0200 (CEST) Date: Sun, 21 Jun 2015 17:04:50 +0200 Message-ID: <87y4jd3xwt.wl-jch@pps.univ-paris-diderot.fr> From: Juliusz Chroboczek To: Eric Dumazet In-Reply-To: <1434697811.31511.9.camel@edumazet-glaptop2.roam.corp.google.com> References: <87y4jgbejc.wl-jch@pps.univ-paris-diderot.fr> <6644BD81-1FFC-450C-89FD-91E138B7824A@gmail.com> <1434697811.31511.9.camel@edumazet-glaptop2.roam.corp.google.com> User-Agent: Wanderlust/2.15.9 MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") Content-Type: text/plain; format=flowed; charset=US-ASCII Cc: bloat Subject: Re: [Bloat] using tcp_notsent_lowat in various apps? X-BeenThere: bloat@lists.bufferbloat.net X-Mailman-Version: 2.1.13 Precedence: list List-Id: General list for discussing Bufferbloat List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 21 Jun 2015 15:05:24 -0000 [Removed bloat-devel from the CC] > [1] Already sent data [...] > [2] Not sent data. [...] > While NOTSENT_LOWAT is able to restrict (2) only, avoiding filling write > queue when/if no drops are actually seen. Thanks for the explanation, Eric. Do you have any concrete examples where this has been found to yield better results than what the kernel can do on its own? I'm probably missing something, but my intuition is that conversational protocols should be naturally self-pacing, while for streaming protocols the right amount of buffering depends on the kernel latency, and hence should be better done by the kernel itself. -- Juliusz