Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965083AbWHUMmi (ORCPT ); Mon, 21 Aug 2006 08:42:38 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S965080AbWHUMmh (ORCPT ); Mon, 21 Aug 2006 08:42:37 -0400 Received: from filfla-vlan276.msk.corbina.net ([213.234.233.49]:24281 "EHLO screens.ru") by vger.kernel.org with ESMTP id S965090AbWHUMmg (ORCPT ); Mon, 21 Aug 2006 08:42:36 -0400 Date: Mon, 21 Aug 2006 21:06:38 +0400 From: Oleg Nesterov To: Andrew Morton Cc: Ingo Molnar , Thomas Gleixner , Steven Rostedt , linux-kernel@vger.kernel.org Subject: [PATCH 3/3] sys_get_robust_list: don't take tasklist_lock Message-ID: <20060821170638.GA1646@oleg> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.11 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1116 Lines: 39 use rcu locks for find_task_by_pid(). Signed-off-by: Oleg Nesterov --- 2.6.18-rc4/kernel/futex.c~3_sgrl 2006-08-21 20:41:15.000000000 +0400 +++ 2.6.18-rc4/kernel/futex.c 2006-08-21 20:59:24.000000000 +0400 @@ -1682,7 +1682,7 @@ sys_get_robust_list(int pid, struct robu struct task_struct *p; ret = -ESRCH; - read_lock(&tasklist_lock); + rcu_read_lock(); p = find_task_by_pid(pid); if (!p) goto err_unlock; @@ -1691,7 +1691,7 @@ sys_get_robust_list(int pid, struct robu !capable(CAP_SYS_PTRACE)) goto err_unlock; head = p->robust_list; - read_unlock(&tasklist_lock); + rcu_read_unlock(); } if (put_user(sizeof(*head), len_ptr)) @@ -1699,7 +1699,7 @@ sys_get_robust_list(int pid, struct robu return put_user(head, head_ptr); err_unlock: - read_unlock(&tasklist_lock); + rcu_read_unlock(); return ret; } - 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/