Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759249AbZFRWrl (ORCPT ); Thu, 18 Jun 2009 18:47:41 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755652AbZFRWr3 (ORCPT ); Thu, 18 Jun 2009 18:47:29 -0400 Received: from victor.provo.novell.com ([137.65.250.26]:35345 "EHLO victor.provo.novell.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758594AbZFRWr3 (ORCPT ); Thu, 18 Jun 2009 18:47:29 -0400 Message-ID: <4A3AC3F6.8070402@novell.com> Date: Thu, 18 Jun 2009 18:47:18 -0400 From: Gregory Haskins User-Agent: Thunderbird 2.0.0.21 (Macintosh/20090302) MIME-Version: 1.0 To: Davide Libenzi CC: "Michael S. Tsirkin" , kvm@vger.kernel.org, Linux Kernel Mailing List , avi@redhat.com, paulmck@linux.vnet.ibm.com, Ingo Molnar Subject: Re: [KVM-RFC PATCH 1/2] eventfd: add an explicit srcu based notifier interface References: <20090616022041.23890.90120.stgit@dev.haskins.net> <20090616022956.23890.63776.stgit@dev.haskins.net> <20090616140240.GA9401@redhat.com> <4A37A7FC.4090403@novell.com> <20090616143816.GA18196@redhat.com> <4A37B0BB.3020005@novell.com> <20090616145502.GA1102@redhat.com> <4A37B832.6040206@novell.com> <20090616154150.GA17494@redhat.com> <4A37C592.2030407@novell.com> <4A37CFDA.4000602@novell.com> <4A3927C0.5060607@novell.com> <4A39415C.9060803@novell.com> <4A39649C.4020602@novell.com> <4A3A48AB.2080206@novell.com> <4A3A8FBC.10905@novell.com> In-Reply-To: X-Enigmail-Version: 0.95.7 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enigF84FCBB5B142CD83B0C69845" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2658 Lines: 83 This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enigF84FCBB5B142CD83B0C69845 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Davide Libenzi wrote: > On Thu, 18 Jun 2009, Gregory Haskins wrote: > > =20 >> Davide Libenzi wrote: >> =20 >>> On Thu, 18 Jun 2009, Gregory Haskins wrote: >>> >>> =20 >>> =20 >>>> Actually there is only one (the tx-thread) aside from the eventfd >>>> imposed workqueue one. Incidentally, I would love to get rid of the= >>>> other thread too, so I am not just picking on eventfd ;). The other= is >>>> a lot harder since it has to update the virtio-ring and may need to = page >>>> in guest memory to do so. >>>> =20 >>>> =20 >>> No, there is the interface rx softirq too, that makes two. >>> =20 >> Actually, I believe you are mistaken. It normally executes the softir= q >> in interrupt context, not a thread. >> >> But I digress. Lets just shelve the SRCU conversation for another day= =2E=20 >> It was my bad for introducing it now prematurely to solve a mostly >> unrelated problem: the module-reference thing. I didn't realize the >> SRCU change would be so controversial, and I didn't think to split >> things apart as I have done today. >> >> But the fact is: I do not see any way to actually use your referencele= ss >> POLLHUP release code in a race free way without doing something like I= >> propose in 3/4, 4/4. Lets keep the discussion focused on that for no= w, >> if we could. >> =20 > > OK, since I got literally swamped by the amount of talks and patches ov= er=20 > this theoretically simple topic, would you mind 1) posting the global = > patch over eventfd 2) describe exactly what races are you talking abou= t=20 > 3) explain why this should be any concern of eventfd at all? > > > =20 Yes, I can do that. Thanks Davide, -Greg --------------enigF84FCBB5B142CD83B0C69845 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG/MacGPG2 v2.0.11 (Darwin) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iEYEARECAAYFAko6w/YACgkQlOSOBdgZUxnanwCfeTGC0kMezSt5VSUa4Hxg4mUf N8IAmwZxSU4XGKrcTqXVH+Qaxuw1UyXN =Zu08 -----END PGP SIGNATURE----- --------------enigF84FCBB5B142CD83B0C69845-- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/