Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030257AbWJXJrg (ORCPT ); Tue, 24 Oct 2006 05:47:36 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1030258AbWJXJrg (ORCPT ); Tue, 24 Oct 2006 05:47:36 -0400 Received: from amsfep17-int.chello.nl ([213.46.243.15]:64737 "EHLO amsfep19-int.chello.nl") by vger.kernel.org with ESMTP id S1030257AbWJXJrf (ORCPT ); Tue, 24 Oct 2006 05:47:35 -0400 Subject: Re: [PATCH] do_acct_process: don't take tty_mutex From: Peter Zijlstra To: Oleg Nesterov Cc: Andrew Morton , Alan Cox , linux-kernel@vger.kernel.org In-Reply-To: <20061023135644.GA1501@oleg> References: <20061023135644.GA1501@oleg> Content-Type: text/plain Date: Tue, 24 Oct 2006 11:48:15 +0200 Message-Id: <1161683295.24143.12.camel@taijtu> Mime-Version: 1.0 X-Mailer: Evolution 2.6.3 (2.6.3-1.fc5.5) Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1303 Lines: 35 On Mon, 2006-10-23 at 17:56 +0400, Oleg Nesterov wrote: > Depends on > tty-signal-tty-locking.patch > > No need to take the global tty_mutex, signal->tty->driver can't go away > while we are holding ->siglock. > > Signed-off-by: Oleg Nesterov Acked-by: Peter Zijlstra --- rc2-mm2/kernel/acct.c~ 2006-10-22 19:28:17.000000000 +0400 > +++ rc2-mm2/kernel/acct.c 2006-10-23 17:09:12.000000000 +0400 > @@ -484,12 +484,9 @@ static void do_acct_process(struct file > ac.ac_ppid = current->parent->tgid; > #endif > > - mutex_lock(&tty_mutex); > - tty = get_current_tty(); > - ac.ac_tty = tty ? old_encode_dev(tty_devnum(tty)) : 0; > - mutex_unlock(&tty_mutex); > - > spin_lock_irq(¤t->sighand->siglock); > + tty = current->signal->tty; > + ac.ac_tty = tty ? old_encode_dev(tty_devnum(tty)) : 0; > ac.ac_utime = encode_comp_t(jiffies_to_AHZ(cputime_to_jiffies(pacct->ac_utime))); > ac.ac_stime = encode_comp_t(jiffies_to_AHZ(cputime_to_jiffies(pacct->ac_stime))); > ac.ac_flag = pacct->ac_flag; > - 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/