Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932692AbVKYPDi (ORCPT ); Fri, 25 Nov 2005 10:03:38 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932693AbVKYPDi (ORCPT ); Fri, 25 Nov 2005 10:03:38 -0500 Received: from mail.tv-sign.ru ([213.234.233.51]:26010 "EHLO several.ru") by vger.kernel.org with ESMTP id S932692AbVKYPDh (ORCPT ); Fri, 25 Nov 2005 10:03:37 -0500 Message-ID: <43873940.71D85208@tv-sign.ru> Date: Fri, 25 Nov 2005 19:18:08 +0300 From: Oleg Nesterov X-Mailer: Mozilla 4.76 [en] (X11; U; Linux 2.2.20 i686) X-Accept-Language: en MIME-Version: 1.0 To: Ingo Molnar Cc: linux-kernel@vger.kernel.org, Andrew Morton Subject: [PATCH 1/2] v2 PF_DEAD: cleanup usage Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1793 Lines: 47 schedule() checks PF_DEAD on every context switch, and sets ->state = EXIT_DEAD to ensure that exited task will be deactivated. It is possible to set new ->state value in do_exit(), along with PF_DEAD flag, and remove the check from schedule()'s hot path. To avoid mixing ->state/->exit_state values, this patch adds new TASK_DEAD state. Signed-off-by: Oleg Nesterov --- 2.6.15-rc2/include/linux/sched.h~1_CLEAN 2005-11-25 20:58:09.000000000 +0300 +++ 2.6.15-rc2/include/linux/sched.h 2005-11-25 21:02:22.000000000 +0300 @@ -127,6 +127,7 @@ extern unsigned long nr_iowait(void); #define EXIT_DEAD 32 /* in tsk->state again */ #define TASK_NONINTERACTIVE 64 +#define TASK_DEAD 128 #define __set_task_state(tsk, state_value) \ do { (tsk)->state = (state_value); } while (0) --- 2.6.15-rc2/kernel/exit.c~1_CLEAN 2005-11-25 20:58:14.000000000 +0300 +++ 2.6.15-rc2/kernel/exit.c 2005-11-25 21:04:26.000000000 +0300 @@ -875,6 +875,7 @@ fastcall NORET_TYPE void do_exit(long co preempt_disable(); BUG_ON(tsk->flags & PF_DEAD); tsk->flags |= PF_DEAD; + tsk->state = TASK_DEAD; schedule(); BUG(); --- 2.6.15-rc2/kernel/sched.c~1_CLEAN 2005-11-25 20:58:14.000000000 +0300 +++ 2.6.15-rc2/kernel/sched.c 2005-11-25 21:04:48.000000000 +0300 @@ -3000,9 +3000,6 @@ need_resched_nonpreemptible: spin_lock_irq(&rq->lock); - if (unlikely(prev->flags & PF_DEAD)) - prev->state = EXIT_DEAD; - switch_count = &prev->nivcsw; if (prev->state && !(preempt_count() & PREEMPT_ACTIVE)) { switch_count = &prev->nvcsw; - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/