From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753350AbYIPUrt (ORCPT ); Tue, 16 Sep 2008 16:47:49 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751385AbYIPUrl (ORCPT ); Tue, 16 Sep 2008 16:47:41 -0400 Received: from ug-out-1314.google.com ([66.249.92.171]:21187 "EHLO ug-out-1314.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751417AbYIPUrk (ORCPT ); Tue, 16 Sep 2008 16:47:40 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:from:to:content-type:content-transfer-encoding :mime-version:subject:date:x-mailer; b=cziOu1YHW3xHR7bWihJ3iFHZ5y7A+hYmrtTKCkCq13y3JAk26Q0AP2V7ubnTYZff8q H7dwTotdxb8PXxep8zDHB5zPX6wbgAOylswcHujc2KEAiWKfOcBPOAL5rAXhcXOks+2e T9GfMw9hGeJ4MjEP/fb1dxaSn6em3cvzcGrNc= Message-Id: From: Chase Douglas To: linux-kernel@vger.kernel.org Content-Type: text/plain; charset=US-ASCII; format=flowed; delsp=yes Content-Transfer-Encoding: 7bit Mime-Version: 1.0 (Apple Message framework v929.2) Subject: Signal debugging/tracing Date: Tue, 16 Sep 2008 16:47:34 -0400 X-Mailer: Apple Mail (2.929.2) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org I'm debugging a uClibc pthreads issue that occurs during a stress test where many threads are looping many times forking off child processes that exec() other executables. Child processes are writing to a pipe that the parent threads are reading. After some iterations in the loops, the threads that are reading from the pipe using read() are getting EINTR. If you put the read in a loop so that an EINTR is ignored and you just try again, each subsequent read call returns immediately with EINTR again. I'm assuming right now that the EINTR is due to a stray signal occurring somewhere, probably due to pthreads. Unfortunately, my debugging isn't showing that the process is signaling any other process or itself in a way that would cause an EINTR. All I see are SIGRTMIN signals getting raised. If it truly is an issue of signals being raised, what techniques can be used to determine what signals are being sent to the process and from where are the signals coming from? Thanks, Chase Douglas