From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeremy Fitzhardinge Subject: Re: Re: [PATCH] xen: events: do not unmask polled ipis on restore. Date: Fri, 29 Oct 2010 10:42:33 -0700 Message-ID: <4CCB0789.4040203@goop.org> References: <1288341238-3059-1-git-send-email-ian.campbell@citrix.com> <4CCAF9E1.70902@goop.org> <1288373709.8069.23.camel@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1288373709.8069.23.camel@localhost.localdomain> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Ian Campbell Cc: "xen-devel@lists.xensource.com" List-Id: xen-devel@lists.xenproject.org On 10/29/2010 10:35 AM, Ian Campbell wrote: > On Fri, 2010-10-29 at 17:44 +0100, Jeremy Fitzhardinge wrote: >> On 10/29/2010 01:33 AM, Ian Campbell wrote: >>> The Xen PV spinlock backend attempts to setup an IPI to IRQ binding >>> which is only to be used via xen_poll_irq rather received directly. >>> >>> Unfortunately restore_cpu_ipis unconditionally unmasks each IPI >>> leading to: >> Gosh I wonder why we hadn't seen this before? > I must admit I don't normally enable CONFIG_PARAVIRT_SPINLOCKS I > happened to be running someone else's config when I noticed this. > > Possibly relates to switching to the edge triggered handler and the > related mask/unmask vs clear etc frobbing? Possibly. Did you see my comment further down? J > > > _______________________________________________ > Xen-devel mailing list > Xen-devel@lists.xensource.com > http://lists.xensource.com/xen-devel >