Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751376AbWE2VbS (ORCPT ); Mon, 29 May 2006 17:31:18 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751377AbWE2V1Q (ORCPT ); Mon, 29 May 2006 17:27:16 -0400 Received: from mx3.mail.elte.hu ([157.181.1.138]:40427 "EHLO mx3.mail.elte.hu") by vger.kernel.org with ESMTP id S1751369AbWE2V1H (ORCPT ); Mon, 29 May 2006 17:27:07 -0400 Date: Mon, 29 May 2006 23:27:27 +0200 From: Ingo Molnar To: linux-kernel@vger.kernel.org Cc: Arjan van de Ven , Andrew Morton Subject: [patch 54/61] lock validator: special locking: mmap_sem Message-ID: <20060529212727.GB3155@elte.hu> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20060529212109.GA2058@elte.hu> User-Agent: Mutt/1.4.2.1i X-ELTE-SpamScore: 0.0 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=0.0 required=5.9 tests=AWL autolearn=no SpamAssassin version=3.0.3 0.0 AWL AWL: From: address is in the auto white-list X-ELTE-VirusStatus: clean Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1444 Lines: 46 From: Ingo Molnar teach special (recursive) locking code to the lock validator. Has no effect on non-lockdep kernels. Signed-off-by: Ingo Molnar Signed-off-by: Arjan van de Ven --- kernel/exit.c | 2 +- kernel/fork.c | 5 ++++- 2 files changed, 5 insertions(+), 2 deletions(-) Index: linux/kernel/exit.c =================================================================== --- linux.orig/kernel/exit.c +++ linux/kernel/exit.c @@ -582,7 +582,7 @@ static void exit_mm(struct task_struct * /* more a memory barrier than a real lock */ task_lock(tsk); tsk->mm = NULL; - up_read(&mm->mmap_sem); + up_read_non_nested(&mm->mmap_sem); enter_lazy_tlb(mm, current); task_unlock(tsk); mmput(mm); Index: linux/kernel/fork.c =================================================================== --- linux.orig/kernel/fork.c +++ linux/kernel/fork.c @@ -196,7 +196,10 @@ static inline int dup_mmap(struct mm_str down_write(&oldmm->mmap_sem); flush_cache_mm(oldmm); - down_write(&mm->mmap_sem); + /* + * Not linked in yet - no deadlock potential: + */ + down_write_nested(&mm->mmap_sem, 1); mm->locked_vm = 0; mm->mmap = NULL; - 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/