From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from [140.186.70.92] (port=57368 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1ONPtE-00013U-C5 for qemu-devel@nongnu.org; Sat, 12 Jun 2010 08:32:45 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.69) (envelope-from ) id 1ONPtD-0004LF-Bx for qemu-devel@nongnu.org; Sat, 12 Jun 2010 08:32:44 -0400 Received: from fmmailgate01.web.de ([217.72.192.221]:55164) by eggs.gnu.org with esmtp (Exim 4.69) (envelope-from ) id 1ONPtD-0004L6-1Z for qemu-devel@nongnu.org; Sat, 12 Jun 2010 08:32:43 -0400 Message-ID: <4C137E68.6000007@web.de> Date: Sat, 12 Jun 2010 14:32:40 +0200 From: Jan Kiszka MIME-Version: 1.0 Subject: Re: [Qemu-devel] [PATCH 09/16] Enable message delivery via IRQs References: <201006121321.04898.paul@codesourcery.com> In-Reply-To: <201006121321.04898.paul@codesourcery.com> Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enig5D4CC7DFB98F5033A485137E" Sender: jan.kiszka@web.de List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Paul Brook Cc: blue Swirl , Jan Kiszka , qemu-devel@nongnu.org, Gleb Natapov , Juan Quintela This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enig5D4CC7DFB98F5033A485137E Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: quoted-printable Paul Brook wrote: >> This patch allows to optionally attach a message to an IRQ event. The >> message can contain a payload reference and a callback that the IRQ >> handler may invoke to report the delivery result. The former can be us= ed >> to model message signaling interrupts, the latter to cleanly implement= >> IRQ de-coalescing logics. >=20 > I don't like this. qemu_irq is a level triggered interface. Redundant c= alls to=20 > qemu_set_irq should (in principle) be a no-op. If you want message pas= sing=20 > then IMO you should be using something else. I think we all now agree that we need some extension to the qemu_irq interface to realize clean irq de-coalescing. Returning a delivery code was proposed several times but always rejected. Blueswirl brought up that message passing can model this as well and that it has additional use for sparc. So I followed this suggestion, specifically due to the added value and the absence of concerns by other parties. Now, after spending yet another "few" hours on this series, you raise a new concern. Wouldn't it be possible to do this during the design discussion? OK, what is your proposal now for an IRQ de-coalescing framework? Jan --------------enig5D4CC7DFB98F5033A485137E Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.9 (GNU/Linux) Comment: Using GnuPG with SUSE - http://enigmail.mozdev.org iEUEARECAAYFAkwTfmgACgkQitSsb3rl5xQzuACWOC29mS41e41qO0/lrPEZxIty vwCeOii+ZvshPHv126NwrochA3yDwF4= =AKVX -----END PGP SIGNATURE----- --------------enig5D4CC7DFB98F5033A485137E--