From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261514AbVGYUaK (ORCPT ); Mon, 25 Jul 2005 16:30:10 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261655AbVGYUaJ (ORCPT ); Mon, 25 Jul 2005 16:30:09 -0400 Received: from ms-smtp-03.nyroc.rr.com ([24.24.2.57]:41102 "EHLO ms-smtp-03.nyroc.rr.com") by vger.kernel.org with ESMTP id S261545AbVGYU2x (ORCPT ); Mon, 25 Jul 2005 16:28:53 -0400 Subject: [PATCH] fix (again) MAX_USER_RT_PRIO and MAX_RT_PRIO (was: MAX_USER_RT_PRIO and MAX_RT_PRIO are wrong!) From: Steven Rostedt To: LKML Cc: Linus Torvalds , Andrew Morton , Ingo Molnar , Dean Nelson Content-Type: text/plain Organization: Kihon Technologies Date: Mon, 25 Jul 2005 16:28:39 -0400 Message-Id: <1122323319.4895.3.camel@localhost.localdomain> Mime-Version: 1.0 X-Mailer: Evolution 2.2.3 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Andrew, As we discussed in OLS, here's the patch again to fix the code to handle if the values between MAX_USER_RT_PRIO and MAX_RT_PRIO are different. Without this patch, an SMP system will crash if the values are different. I've already submitted this patch and it made it to -mm, but never made it to mainline, so you told me to send it again and here it is. Also, shouldn't these values (MAX_RT_PRIO, MAX_USER_RT_PRIO) be user configurable via a config parameter? If so, I can send a separate patch to do just that. Ingo, I've CC you just because you are the schedule maintainer. You already accepted this patch into your RT tree. Dean, I've CC you since it also has the change to linux-2.6.13-rc3/arch/ia64/sn/kernel/xpc_main.c in it. But I don't see this in -mm. I don't have a ia64 so I can't test it. You tested this for me before, so it should still work. This part should be at least acknowledged by you. -- Steve PS. I'm currently running this patched kernel with MAX_RT_USER set to 95 and MAX_RT_PRIO set to 100 on an SMP machine. Signed-off-by: Steven Rostedt --- linux-2.6.13-rc3/kernel/sched.c.orig 2005-07-25 10:16:31.000000000 -0400 +++ linux-2.6.13-rc3/kernel/sched.c 2005-07-25 10:23:35.000000000 -0400 @@ -3486,7 +3486,7 @@ static void __setscheduler(struct task_s p->policy = policy; p->rt_priority = prio; if (policy != SCHED_NORMAL) - p->prio = MAX_USER_RT_PRIO-1 - p->rt_priority; + p->prio = MAX_RT_PRIO-1 - p->rt_priority; else p->prio = p->static_prio; } @@ -3518,7 +3518,8 @@ recheck: * 1..MAX_USER_RT_PRIO-1, valid priority for SCHED_NORMAL is 0. */ if (param->sched_priority < 0 || - param->sched_priority > MAX_USER_RT_PRIO-1) + (p->mm && param->sched_priority > MAX_USER_RT_PRIO-1) || + (!p->mm && param->sched_priority > MAX_RT_PRIO-1)) return -EINVAL; if ((policy == SCHED_NORMAL) != (param->sched_priority == 0)) return -EINVAL; --- linux-2.6.13-rc3/arch/ia64/sn/kernel/xpc_main.c.orig 2005-07-25 10:23:22.000000000 -0400 +++ linux-2.6.13-rc3/arch/ia64/sn/kernel/xpc_main.c 2005-07-25 10:23:35.000000000 -0400 @@ -420,7 +420,7 @@ xpc_activating(void *__partid) partid_t partid = (u64) __partid; struct xpc_partition *part = &xpc_partitions[partid]; unsigned long irq_flags; - struct sched_param param = { sched_priority: MAX_USER_RT_PRIO - 1 }; + struct sched_param param = { sched_priority: MAX_RT_PRIO - 1 }; int ret;