From mboxrd@z Thu Jan 1 00:00:00 1970 From: John Sigler Subject: Re: Old -rt patches Date: Tue, 07 Aug 2007 10:52:32 +0200 Message-ID: <46B832D0.5030803@free.fr> References: <46B0B7A4.8060805@free.fr> <46B6E210.9090502@free.fr> <20070806144158.GA9309@linux.vnet.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: linux-rt-users@vger.kernel.org, linux-kernel@vger.kernel.org, mingo@elte.hu, tglx@linutronix.de To: paulmck@linux.vnet.ibm.com Return-path: Received: from smtp4-g19.free.fr ([212.27.42.30]:60944 "EHLO smtp4-g19.free.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757570AbXHGIwu (ORCPT ); Tue, 7 Aug 2007 04:52:50 -0400 In-Reply-To: <20070806144158.GA9309@linux.vnet.ibm.com> Sender: linux-rt-users-owner@vger.kernel.org List-Id: linux-rt-users.vger.kernel.org Paul E. McKenney wrote: > John Sigler wrote: > >> I wrote a Linux app where I need high-resolution timers. I went all the >> way and installed the -rt patch, which includes the -hrt patches, as far >> as I understand. >> >> Since I could not afford to change kernels with every new release, I >> decided to track the 2.6.20 branch (arbitrarily). >> >> At this point I'm using 2.6.20.7-rt8 (-rt8 was the last patch to the >> 2.6.20 branch). (I see 2.6.20 is already up to .15) >> >> I see a lot of patches going into the -rt patch, but development moved >> on to 2.6.21, then 2.6.22, and now 2.6.23, following mainline. >> >> I'm not a kernel hacker, so I don't claim to understand the patches, but >> the comments sound like a few bugs are fixed here and there. I can't >> tell whether these bugs also exist in previous kernels or only appeared >> in newer kernels. Even if I knew, I probably wouldn't have the expertise >> to back-port the patch. >> >> I'm seeing weird behavior in my app, when it has been running 2-4 days. >> The timers start to act out, and all hell breaks loose. Basically, I >> have no idea what's going on... >> >> My question is: is it possible that there is a bug in 2.6.20-rt8 that >> has been fixed in subsequent -rt patches (there's a 2.6.21.6-rt21 and a >> 2.6.22.1-rt9)? In other words, if I give 2.6.21.6-rt8 or 2.6.22.1-rt9 a >> spin, is it possible that my weird behavior disappears? >> >> I'm not saying that it's impossible for the bug to be in my app, but the >> app is small enough that I'm fairly confident there's no problem there. > > Would you be willing to post your app so people could try to reproduce > your bug? Hello Paul, I cannot provide the app "as is" (I fear the paranoid PHB would spontaneously combust). If time permits, I will try to make a small testcase to exhibit the problem. Regards.