Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932196Ab2F1Geg (ORCPT ); Thu, 28 Jun 2012 02:34:36 -0400 Received: from mx1.redhat.com ([209.132.183.28]:20954 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752735Ab2F1Gef (ORCPT ); Thu, 28 Jun 2012 02:34:35 -0400 Date: Thu, 28 Jun 2012 09:34:31 +0300 From: Gleb Natapov To: "Michael S. Tsirkin" Cc: Alex Williamson , avi@redhat.com, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, jan.kiszka@siemens.com Subject: Re: [PATCH v2 4/6] kvm: Extend irqfd to support level interrupts Message-ID: <20120628063431.GI6533@redhat.com> References: <20120627044758.23698.249.stgit@bling.home> <20120627050937.23698.68442.stgit@bling.home> <20120627152624.GC21393@redhat.com> <1340834658.1207.261.camel@bling.home> <20120627223128.GB27885@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20120627223128.GB27885@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1461 Lines: 42 On Thu, Jun 28, 2012 at 01:31:29AM +0300, Michael S. Tsirkin wrote: > On Wed, Jun 27, 2012 at 04:04:18PM -0600, Alex Williamson wrote: > > On Wed, 2012-06-27 at 18:26 +0300, Michael S. Tsirkin wrote: > > > On Tue, Jun 26, 2012 at 11:09:46PM -0600, Alex Williamson wrote: > > > > @@ -71,6 +130,14 @@ irqfd_inject(struct work_struct *work) > > > > kvm_set_irq(kvm, KVM_USERSPACE_IRQ_SOURCE_ID, irqfd->gsi, 0); > > > > } > > > > > > > > +static void > > > > +irqfd_inject_level(struct work_struct *work) > > > > +{ > > > > + struct _irqfd *irqfd = container_of(work, struct _irqfd, inject); > > > > + > > > > + kvm_set_irq(irqfd->kvm, irqfd->source->id, irqfd->gsi, 1); > > > > +} > > > > + > > > > /* > > > > * Race-free decouple logic (ordering is critical) > > > > */ > > > > > > > > > Why is it safe to ignore return value here? > > > needs a comment. > > > > Well, it seems like you and Gleb came to the conclusion that it's safe, > > but I can really follow from the list thread. Can you explain and I'll > > add a comment? Thanks, > > > > Alex > > We merely talked about edge interrupts. > In fact it would have been nice to return -EBUSY when write() to level irqfd is coalesced. -- Gleb. -- 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/