From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Mosberger Date: Fri, 12 Jul 2002 17:02:43 +0000 Subject: [Linux-ia64] Re: switch_mm race condition with Ingo's scheduler 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 Fri, 12 Jul 2002 18:47:58 +0200, Erich Focht said: Erich> But then other processors would continue using the old TLBs Erich> maybe of tasks which died. The problem is that we need to do Erich> a TLB flush on all CPUs when wrapping around the Erich> context. Otherwise we might reuse the context number of a Erich> recently exited process and on other CPUs some of its TLB Erich> entries may survive until the new task switches CPUs. Hard to Erich> debug, probably... But the only time you might reuse an old context number is when you allocate one. Yes, you will have old entries hanging around in the TLB for a while, but you _know_ that the corresponding tasks already died and you also know that you'll flush the TLB before re-using one of those context numbers. --david