From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Mosberger Date: Fri, 14 Mar 2003 21:24:44 +0000 Subject: Re: [Linux-ia64] Pre-emption patch for IA-64 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 Peter Chubb has been working on adding preemption support to 2.5. I applied his patch in the 2.5.64 patch. I'm sure he would appreciate more people beating on it. --david >>>>> On Fri, 14 Mar 2003 11:21:21 -0600, Mario Smarduch said: Mario> Hi, we're trying to build a reliable low-latency system for Mario> use in telco call processing carrier grade environments (on Mario> rx2600 NEBS like servers) . One of the patches we're heavily Mario> relying on is the 'Kernel Preemption' patch. First of we're Mario> interested in the (i) status of this patch on IA-64 (ii) any Mario> issues that you may have ran into. Mario> Our understanding is that the 'Preemption Patch' offers a Mario> systematic scheduling checkpoint vs. 'low latency patch' Mario> which examines the kernel for any long running code and based Mario> on that preemption checks are inserted in the kernel proper Mario> only (kernel.org) but addon packages may introduce long Mario> latencies. While we plan to run with 1mS clock tick, low Mario> latency and the preemption paches, the preemption patch is Mario> viewed as a must to gurantee a bound on 'soft-realtime Mario> response'. Please point out if these assumption are somewhat Mario> correct or is too much emphasis being placed on the Mario> preemption patch, the soft-realtime response we're looking Mario> for is 1mS.