From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752115AbWFLQL0 (ORCPT ); Mon, 12 Jun 2006 12:11:26 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752116AbWFLQL0 (ORCPT ); Mon, 12 Jun 2006 12:11:26 -0400 Received: from adsl-70-250-156-241.dsl.austtx.swbell.net ([70.250.156.241]:56200 "EHLO gw.microgate.com") by vger.kernel.org with ESMTP id S1752115AbWFLQL0 (ORCPT ); Mon, 12 Jun 2006 12:11:26 -0400 Message-ID: <448D922F.80801@microgate.com> Date: Mon, 12 Jun 2006 11:11:27 -0500 From: Paul Fulghum User-Agent: Mozilla Thunderbird 1.0 (Windows/20041206) X-Accept-Language: en-us, en MIME-Version: 1.0 To: Alan Cox CC: Chuck Ebbert <76306.1226@compuserve.com>, linux-kernel Subject: Re: 2.6.16.18 kernel freezes while pppd is exiting References: <200606081909_MC3-1-C1F0-8B6B@compuserve.com> <1150124830.3703.6.camel@amdx2.microgate.com> <1150127588.25462.7.camel@localhost.localdomain> In-Reply-To: <1150127588.25462.7.camel@localhost.localdomain> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Alan Cox wrote: >> spin_unlock_irqrestore(&tty->buf.lock, flags); >>+ clear_bit(TTY_FLUSHING, &tty->flags); > > > Shouldn't those two be reversed if you want to go with this path. I don't see that is necessary. > How is this occuring anyway the flush_to_ldisc path should never re-enter. If a driver has low_latency set, flush_to_ldisc can be called from both scheduled work (due to hitting TTY_DONT_FLIP) and directly from an ISR. On an SMP system, they can run in parallel. I don't know for sure that is the path being hit, it could be some other odd combination. But there is no inherent serialization of flush_to_ldisc. -- Paul Fulghum Microgate Systems, Ltd.