From mboxrd@z Thu Jan 1 00:00:00 1970 From: Richard Henderson Date: Wed, 05 Dec 2001 16:58:08 +0000 Subject: [Linux-ia64] Re: alpha bug in signal handling Message-Id: List-Id: References: In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-ia64@vger.kernel.org On Wed, Dec 05, 2001 at 03:23:04AM -0800, David S. Miller wrote: > I don't understand why this is even necessary. > > What if the interrupt comes in on another processor. How does this > return from trap behavior avoid that interrupt modifying the signal > and/or scheduling state wrt. the current cpu's task? It doesn't. But it also prevents the IPI from being recognized until we are back in userland. Apparently DMT had a test case that failed without disabling interrupts; I didn't see it myself. r~