From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757547AbZEGGwc (ORCPT ); Thu, 7 May 2009 02:52:32 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755219AbZEGGvU (ORCPT ); Thu, 7 May 2009 02:51:20 -0400 Received: from mx2.redhat.com ([66.187.237.31]:36271 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755366AbZEGGvT (ORCPT ); Thu, 7 May 2009 02:51:19 -0400 Date: Thu, 7 May 2009 08:46:41 +0200 From: Oleg Nesterov To: Andrew Morton Cc: Ingo Molnar , Roland McGrath , Vitaly Mayatskikh , linux-kernel@vger.kernel.org Subject: [PATCH 3/5] do_wait: simplify retval/tsk_result/notask_error mess Message-ID: <20090507064641.GA15864@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Now that we don't pass &retval down to other helpers we can simplify the code more. - kill tsk_result, just use retval - add the "notask" label right after the main loop, and s/got end/goto notask/ after the fastpath pid check. This way we don't need to initialize retval before this check and the code becomes a bit more clean, if this pid has no attached tasks we should just skip the list search. Signed-off-by: Oleg Nesterov --- kernel/exit.c | 20 ++++++++------------ 1 file changed, 8 insertions(+), 12 deletions(-) --- PTRACE/kernel/exit.c~3_RETVAL 2009-05-07 04:37:49.000000000 +0200 +++ PTRACE/kernel/exit.c 2009-05-07 05:09:51.000000000 +0200 @@ -1576,27 +1576,22 @@ repeat: * might later match our criteria, even if we are not able to reap * it yet. */ - retval = wo->notask_error = -ECHILD; + wo->notask_error = -ECHILD; if ((wo->wo_type < PIDTYPE_MAX) && (!wo->wo_pid || hlist_empty(&wo->wo_pid->tasks[wo->wo_type]))) - goto end; + goto notask; current->state = TASK_INTERRUPTIBLE; read_lock(&tasklist_lock); tsk = current; do { - int tsk_result = do_wait_thread(wo, tsk); - - if (!tsk_result) - tsk_result = ptrace_do_wait(wo, tsk); + retval = do_wait_thread(wo, tsk); + if (retval) + goto end; - if (tsk_result) { - /* - * tasklist_lock is unlocked and we have a final result. - */ - retval = tsk_result; + retval = ptrace_do_wait(wo, tsk); + if (retval) goto end; - } if (wo->wo_flags & __WNOTHREAD) break; @@ -1605,6 +1600,7 @@ repeat: } while (tsk != current); read_unlock(&tasklist_lock); +notask: retval = wo->notask_error; if (!retval && !(wo->wo_flags & WNOHANG)) { retval = -ERESTARTSYS;