From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephane Eranian Date: Mon, 13 Feb 2006 20:12:39 +0000 Subject: Re: PMU and timer interrupts Message-Id: <20060213201239.GH11285@frankl.hpl.hp.com> List-Id: References: <20060209171648.GA26865@frankl.hpl.hp.com> In-Reply-To: <20060209171648.GA26865@frankl.hpl.hp.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-ia64@vger.kernel.org On Mon, Feb 13, 2006 at 12:13:06PM -0800, Chen, Kenneth W wrote: > Stephane Eranian wrote on Monday, February 13, 2006 12:02 PM > > On Fri, Feb 10, 2006 at 03:04:57PM -0800, Chen, Kenneth W wrote: > > > In fact, most of the interrupts having SA_INTERRUPT flag set. So the > > > blind spots you worried about for PMU is a lot wider. For example, on > > > my system, serial, e1000, mpt fusion, qla2300 interrupts all have that > > > flag set. Looks like kernel executes these handlers with irq disabled > > > all the way through. > > > > > Looking at my 2.6.16-rc1, it appears that neither e1000 nor mpt fusion > > are using SA_INTERRUPT anymore. The qla2xxx still does, though. > > Yeah, I think you are correct. Jes seems to believe than this is more historical than anything for qla2xxx. Now what about the timer interrupt, why does it really need SA_INTERRUPT especially given that it is so high priority and with the TPR mechanism. IT seems to be a protection against MCA, IPI, IPI_RESCHEDULE based on the current layout. -- -Stephane