Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757305AbZFQQpS (ORCPT ); Wed, 17 Jun 2009 12:45:18 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754355AbZFQQpG (ORCPT ); Wed, 17 Jun 2009 12:45:06 -0400 Received: from x35.xmailserver.org ([64.71.152.41]:49425 "EHLO x35.xmailserver.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752623AbZFQQpF (ORCPT ); Wed, 17 Jun 2009 12:45:05 -0400 X-AuthUser: davidel@xmailserver.org Date: Wed, 17 Jun 2009 09:38:55 -0700 (PDT) From: Davide Libenzi X-X-Sender: davide@makko.or.mcafeemobile.com To: Gregory Haskins 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 In-Reply-To: <4A37CFDA.4000602@novell.com> Message-ID: 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> User-Agent: Alpine 1.10 (DEB 962 2008-03-14) X-GPG-FINGRPRINT: CFAE 5BEE FD36 F65E E640 56FE 0974 BF23 270F 474E X-GPG-PUBLIC_KEY: http://www.xmailserver.org/davidel.asc MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1620 Lines: 49 On Tue, 16 Jun 2009, Gregory Haskins wrote: > Davide Libenzi wrote: > > On Tue, 16 Jun 2009, Gregory Haskins wrote: > > > > > >> Does this all make sense? > >> > > > > This conversation has been *really* long, and I haven't had time to look > > at the patch yet. But looking at the amount of changes, and the amount of > > even more changes talked in this thread, there's a very slim chance that > > I'll ACK the eventfd code. > > You may want to consider a solution that does not litter eventfd code that > > much. > > > > > > - Davide > > > > > > > Hi Davide, > > I understand your position and value your time/insight into looking at > this things. > > Despite the current ongoing discussion, I still stand that the current > patch is my proposed solution (though I have yet to convince Michael). > But in any case, if you have the time, please look it over because I > still think its the right direction to head in. I don't think so. You basically upload a bunch of stuff it could have been inside your irqfd into eventfd. Now the eventfd_signal() can magically sleep, or not, depending on what the signal functions do. This makes up a pretty aweful interface if you ask me. A lot simpler and cleaner if eventfd_signal(), like all the wake up functions inside the kernel, can be called from atomic context. Always, not sometimes. - Davide -- 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/