X-Recipient: archive-cygwin@delorie.com X-SWARE-Spam-Status: No, hits=-1.3 required=5.0 tests=AWL,BAYES_00,SPF_HELO_PASS,T_RP_MATCHES_RCVD X-Spam-Check-By: sourceware.org Message-ID: <4F0BEE4E.2040605@dancol.org> Date: Mon, 09 Jan 2012 23:52:46 -0800 From: Daniel Colascione User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.6; rv:8.0) Gecko/20111105 Thunderbird/8.0 MIME-Version: 1.0 To: cygwin@cygwin.com Subject: Re: socket performance References: <95814509-4E08-44C6-8E59-026225EC0FF5@playsafesa.com> <4F04613B.6050505@gmail.com> <20120109134311.GH15470@calimero.vinschen.de> In-Reply-To: Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enigD9CCF92DD09FA11FC51AEA10" X-IsSubscribed: yes Mailing-List: contact cygwin-help@cygwin.com; run by ezmlm List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: cygwin-owner@cygwin.com Mail-Followup-To: cygwin@cygwin.com Delivered-To: mailing list cygwin@cygwin.com --------------enigD9CCF92DD09FA11FC51AEA10 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable On 1/9/12 11:22 PM, Henry S. Thompson wrote: > Corinna Vinschen writes: >=20 >> it's nice to know that you could increase the performance by increasing >> the buffer sizes. However, I'm reluctant to implement this as a generic >> option. As far as I know the socket buffers are taken from nonpaged poo= l, >> so generically using 2 Meg buffers will take a lot of precious resources. >=20 > And contribute to bufferbloat problems [1] [2] elsewhere! Large socket buffers don't contribute bufferbloat: a socket's send-buffer holds bytes, not packets. It sits above TCP on the networking stack, thus doesn't affect TCP's flow control decisions. Bufferbloat happens when deep IP-packet buffers confuse TCP's congestion avoidance, not when the OS feeds bytes to TCP more efficiently. Of course, using a larger socket buffer _can_ increase the send(2)-to-wire latency, but that's not quite the same thing as bufferbloat. --------------enigD9CCF92DD09FA11FC51AEA10 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.11 (Darwin) Comment: GPGTools - http://gpgtools.org iEYEARECAAYFAk8L7k4ACgkQ17c2LVA10Vt6uwCfa8jMOk3KkjGE9KMxLRxjrBB2 8+wAnR8Jk6HUoizwVBq6iths6ERTFBBb =ujX5 -----END PGP SIGNATURE----- --------------enigD9CCF92DD09FA11FC51AEA10--