Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754704AbYFPQaQ (ORCPT ); Mon, 16 Jun 2008 12:30:16 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754470AbYFPQ3s (ORCPT ); Mon, 16 Jun 2008 12:29:48 -0400 Received: from x346.tv-sign.ru ([89.108.83.215]:33072 "EHLO mail.screens.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754323AbYFPQ3r (ORCPT ); Mon, 16 Jun 2008 12:29:47 -0400 Date: Mon, 16 Jun 2008 20:31:46 +0400 From: Oleg Nesterov To: Andrew Morton Cc: Roland McGrath , linux-kernel@vger.kernel.org Subject: [PATCH 4/4] coredump: turn core_state->nr_threads into atomic_t Message-ID: <20080616163146.GA21052@tv-sign.ru> 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 List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1747 Lines: 53 Turn core_state->nr_threads into atomic_t and kill now unneeded down_write(&mm->mmap_sem) in exit_mm(). Signed-off-by: Oleg Nesterov include/linux/mm_types.h | 2 +- kernel/exit.c | 5 ++--- fs/exec.c | 2 +- 3 files changed, 4 insertions(+), 5 deletions(-) --- 26-rc2/include/linux/mm_types.h~4_NR_ATOMIC 2008-06-15 15:26:29.000000000 +0400 +++ 26-rc2/include/linux/mm_types.h 2008-06-16 18:00:08.000000000 +0400 @@ -160,7 +160,7 @@ struct vm_area_struct { }; struct core_state { - int nr_threads; + atomic_t nr_threads; struct completion startup; }; --- 26-rc2/kernel/exit.c~4_NR_ATOMIC 2008-06-15 15:28:21.000000000 +0400 +++ 26-rc2/kernel/exit.c 2008-06-16 19:58:59.000000000 +0400 @@ -667,10 +667,9 @@ static void exit_mm(struct task_struct * down_read(&mm->mmap_sem); if (mm->core_state) { up_read(&mm->mmap_sem); - down_write(&mm->mmap_sem); - if (!--mm->core_state->nr_threads) + + if (atomic_dec_and_test(&mm->core_state->nr_threads)) complete(&mm->core_state->startup); - up_write(&mm->mmap_sem); wait_for_completion(&mm->core_done); down_read(&mm->mmap_sem); --- 26-rc2/fs/exec.c~4_NR_ATOMIC 2008-06-16 17:23:59.000000000 +0400 +++ 26-rc2/fs/exec.c 2008-06-16 19:59:26.000000000 +0400 @@ -1585,7 +1585,7 @@ static inline int zap_threads(struct tas } rcu_read_unlock(); done: - core_state->nr_threads = nr; + atomic_set(&core_state->nr_threads, nr); mm->core_state = core_state; return nr; } -- 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/