From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262163AbUJZHfg (ORCPT ); Tue, 26 Oct 2004 03:35:36 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262168AbUJZHfg (ORCPT ); Tue, 26 Oct 2004 03:35:36 -0400 Received: from mproxy.gmail.com ([216.239.56.241]:25569 "EHLO mproxy.gmail.com") by vger.kernel.org with ESMTP id S262163AbUJZHed (ORCPT ); Tue, 26 Oct 2004 03:34:33 -0400 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com; h=received:message-id:date:from:reply-to:to:subject:mime-version:content-type:content-transfer-encoding; b=Byh2j0w9VEPhGkXEoIcHV5Qa+WJkcL0Rv29IP4SehBiRzSQ1EF2wHNykYEnwcJoxssrzk7stjIByiOVmqAWKWoqpBUASdi0WmRKL3h8Lvj1ztYlJyshqJshsOP/LDh8qIDGYWuLDR9Jtc2huMUrj/SsoNT9nrntZ+WVb02jvL78= Message-ID: <21d7e99704102600347d8f6f8f@mail.gmail.com> Date: Tue, 26 Oct 2004 17:34:29 +1000 From: Dave Airlie Reply-To: Dave Airlie To: Linux Kernel Mailing List Subject: Serial console blocking processes in write Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hi, I've got a system running a 2.6.9-rc1-VP-R0 (it also happens with 2.6.6 vanilla though) kernel, and a busybox 1.00-pre8 along with about 4-5 user space processes all talking out through a serial console (/dev/ttyS0). After about 2-3 hours of constant stuff streaming out of the serial port, my apps all hang on writes to the fd for stderr, (2->/dev/ttyS0 in /proc//fd). busybox seems to initially open the ttyS0 device as O_NONBLOCK so I would assume this propogates down to my applications as they are fork/execed by busybox. However my kernel printks keep coming out the serial port quite happily. If I then type any character on the other end of the console, I get 16-bytes of data (a FIFO load) sent, so if I keep transmitting chars to the other end, I get 16-bytes for every char and eventually the log jams seems to clear and it runs again fine for another 2-3 hours until it seems to happen again. Any ideas where to start looking, my debugging env is quite crap, but I'm trying to get space on the flash to throw gdb and switch on a lot more debugging, at the moment I've gotten busybox telnetd that I can startup after it crashes, and strace shows be everyone stuck in the writes.... Dave.