X-Recipient:	archive-cygwin AT delorie DOT com
DomainKey-Signature:	a=rsa-sha1; c=nofws; d=sourceware.org; h=list-id
	:list-unsubscribe:list-subscribe:list-archive:list-post
	:list-help:sender:date:from:to:subject:message-id:reply-to
	:references:mime-version:content-type:in-reply-to; q=dns; s=
	default; b=o+dV32h7c434zDWrfK6LtzTVieJuy4JH9tMad5NRXMuhjTQKdW581
	eXZ3Px0sq5HlYg5H/Zvy9V/1bDzSQo7O898b+wcX06Jb/qfTZcSenGKAAGgLuFH0
	fVmwaLXS9hMRkaCwiaUA/H1PauTrOMqBktgcv0ZXpn4V/Vy5+LKeRc=
DKIM-Signature:	v=1; a=rsa-sha1; c=relaxed; d=sourceware.org; h=list-id
	:list-unsubscribe:list-subscribe:list-archive:list-post
	:list-help:sender:date:from:to:subject:message-id:reply-to
	:references:mime-version:content-type:in-reply-to; s=default;
	bh=CxPsyxsbRz7ViZWund2Y0Ef/7Xc=; b=ABa5tOVLGmX0Y+MhTNArbP1ROhHE
	htg/GGrHIcv2hm7G73okst+IcSyDWkoLzZmhpciqPe0sJsUdsZEyQ6g+2tHTcXwm
	A7hqQy9BCFHAzMsj7qB5ep40UMlHujz9Yxbnib1nPSMtijCuXLFBI17xL1+XcmlB
	yojOOvlmmAu7Q6o=
Mailing-List:	contact cygwin-help AT cygwin DOT com; run by ezmlm
List-Id:	<cygwin.cygwin.com>
List-Subscribe:	<mailto:cygwin-subscribe AT cygwin DOT com>
List-Archive:	<http://sourceware.org/ml/cygwin/>
List-Post:	<mailto:cygwin AT cygwin DOT com>
List-Help:	<mailto:cygwin-help AT cygwin DOT com>, <http://sourceware.org/ml/#faqs>
Sender:	cygwin-owner AT cygwin DOT com
Mail-Followup-To:	cygwin AT cygwin DOT com
Delivered-To:	mailing list cygwin AT cygwin DOT com
Authentication-Results:	sourceware.org; auth=none
X-Virus-Found:	No
X-Spam-SWARE-Status:	No, score=-5.9 required=5.0 tests=AWL,BAYES_00 autolearn=ham version=3.3.2
X-HELO:	calimero.vinschen.de
Date:	Mon, 7 Jul 2014 15:41:37 +0200
From:	Corinna Vinschen <corinna-cygwin AT cygwin DOT com>
To:	cygwin AT cygwin DOT com
Subject:	Re: Severe performance degradation of writev
Message-ID:	<20140707134137.GK1803@calimero.vinschen.de>
Reply-To:	cygwin AT cygwin DOT com
Mail-Followup-To:	cygwin AT cygwin DOT com
References:	<lpciht$pc5$1 AT ger DOT gmane DOT org> <20140707101049 DOT GI1803 AT calimero DOT vinschen DOT de>
MIME-Version:	1.0
In-Reply-To:	<20140707101049.GI1803@calimero.vinschen.de>
User-Agent:	Mutt/1.5.23 (2014-03-12)

--656hIAUFSU7Oh46B
Content-Type: text/plain; charset=utf-8
Content-Disposition: inline
Content-Transfer-Encoding: quoted-printable

On Jul  7 12:10, Corinna Vinschen wrote:
> On Jul  7 07:28, jojelino wrote:
> > 2008-07-27  Corinna Vinschen  <corinna AT vinschen DOT de>
> >=20
> >        * fhandler_socket.cc (fhandler_socket::send_internal): Send never
> > more
> >        then 64K bytes at once.  For blocking sockets, loop until entire=
 data
> >        has been sent or an error occurs.
> >        (fhandler_socket::sendto): Drop code which sends on 64K bytes.
> >        (fhandler_socket::sendmsg): Ditto.
> >=20
> > This commit added workaround for KB823764. but it has brought another
> > performance issue when writev sends <64k of data.
>=20
> That's why the code contains that FIXME comment.  If you have a good
> idea for simple code to split a message into the least number of pieces
> to minimize the number of WsaSendTo calls...

I took a stab at the code and I think the new version improves writing
multiple small buffers a lot.  In my testing it still works in other
scenarios, too, but I would be very grateful if somebody could have a
critical look into my code changes as posted in
https://cygwin.com/ml/cygwin-cvs/2014-q3/msg00003.html

I uploaded a new developer snapshot to http://cygwin.com/snapshots/
Please give it a thorough try.


Thanks,
Corinna





--=20
Corinna Vinschen                  Please, send mails regarding Cygwin to
Cygwin Maintainer                 cygwin AT cygwin DOT com
Red Hat

--656hIAUFSU7Oh46B
Content-Type: application/pgp-signature

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1

iQIcBAEBAgAGBQJTuqORAAoJEPU2Bp2uRE+g3LQP/Rdq6+ITuqLW27tb9IT5sRpM
i0fKzL4+S03aurwbQEcl/ti05G6U+6l3eSScewySBdOoRG8u0xkktVnWMgyxkvmr
CsZkP0+gVT+pr+kwPjqmL18ejQCWiKo77QWca4Wql2VR0OJQniPFV9iXh9D5AMNl
X9QirY9K38ZrFSciKMdUHm4XHd+gVCMuxPlVhWy9+q2GlaC9MMhLpEDVnoUYdhoV
HfPXdEbLeFze08syt2UQea1myofjuV8FXe2MsCzsjzqz5QDIQONgFAXc6Fwj2kRL
Al6sPSRJwenYWRsC6mTYEr2dOeu3/ZuWxaaQHx4AC42Q4/o4sZh3wZ+Plew4H8xf
xYRz6CI59t9yVBHEH0wT1SCWZNhn4EfNj9UuWgdEGr8twAJwBEaSvrJdObiB7G31
D07lcUU0uKqzd0vdiFLQZ0farD8mLnDuzTYTdWZ/XweD4zmBoSBxFbWb0JeSYV12
NUA4pJ539Qwj19P6ndGonin+dUteC1WCEwzOD6Hs9sb+SFkxmbmnkDC/PXAXJJSS
WmOaRN7kh9zIGV+ZCPhKPAnUsFY+sKkntYQpihbcP5AS02VQw2iX8yOCHSrlL5Wf
aEnjsH/v5O9PnL/osYgyVrpgaVjOCqIIBFuAOceLJkHu4Olm3LpgqRzqQO3V+dIt
MbZpYnOD9OavNccs8uPa
=M8Uo
-----END PGP SIGNATURE-----

--656hIAUFSU7Oh46B--

- Raw text -