From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Paul E. McKenney" Date: Tue, 10 Feb 2009 12:36:46 +0000 Subject: Re: [PATCH v2 0/2] ia64: prevent irq migration race in Message-Id: <20090210123645.GA7542@linux.vnet.ibm.com> List-Id: References: <20090209181338.GD19064@ldl.fc.hp.com> In-Reply-To: <20090209181338.GD19064@ldl.fc.hp.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Alex Chiang , tony.luck@intel.com, stable@kernel.org, linux-ia64@vger.kernel.org, linux-kernel On Mon, Feb 09, 2009 at 11:13:38AM -0700, Alex Chiang wrote: > This is v2 of my attempt to prevent an oops while offlining CPUs. > > The change is that the patch becomes a full revert of Paul's > original patch, along with a long changelog that explains the > situation as best as I can determine. It's not 100% satisfactory > to me right now, but the testing we've done supports the patch. > > The 2nd patch in the series is mostly cosmetic, and removes a > redundant call to cpu_clear() that we no longer need(). > > Tony, if you agree with the rationale in 1/2, then this series is > a candidate for .29. > > stable team, if Tony pushes upstream for .29, then this series > should be applied to the .27 and .28 stable series. OK, I'll bite... Why not use cpu_active_map rather than cpu_online_map to select which CPU to migrate interrupts to? That way, we can delay clearing the bit in cpu_online_map and avoid the questionable scenario where irqs are being handled by a CPU that appears to be offline. Thanx, Paul