From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 13077 invoked by alias); 24 Aug 2010 17:10:25 -0000 Mailing-List: contact archer-help@sourceware.org; run by ezmlm Sender: Precedence: bulk List-Post: List-Help: List-Subscribe: List-Id: Received: (qmail 13059 invoked by uid 22791); 24 Aug 2010 17:10:21 -0000 X-SWARE-Spam-Status: No, hits=-6.6 required=5.0 tests=AWL,BAYES_00,RCVD_IN_DNSWL_HI,SPF_HELO_PASS,T_RP_MATCHES_RCVD X-Spam-Check-By: sourceware.org Date: Tue, 24 Aug 2010 17:10:00 -0000 From: Oleg Nesterov To: archer@sourceware.org, utrace-devel@redhat.com Subject: Re: gdbstub initial code, v5 Message-ID: <20100824170718.GA8966@redhat.com> References: <20100820173749.GA24358@redhat.com> <20100823185223.GA31912@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20100823185223.GA31912@redhat.com> User-Agent: Mutt/1.5.18 (2008-05-17) X-SW-Source: 2010-q3/txt/msg00127.txt.bz2 On 08/23, Oleg Nesterov wrote: > > However. I spent all Monday trying to resolve the new bug, and > so far I do not understand what happens. Extremely hard to reproduce, > and the kernel just hangs silently, without any message. > So far I suspect the proble in utrace.c, but this time I am not sure. Solved. This was scheduler bug fixed in 2.6.35, but I used 2.6.34. This is really funny. This bug (PF_STARTING lockup) was found and fixed by me & Peter. Oh. But I hit yet another problem, BUG_ON() in __utrace_engine_release(). Again, it is not reproducible, I saw it only once in dmesg and I do not even know for sure what I was doing. I'll contiue tomorrow, but if I won't be able to quickly resolve this problem I am going to ignore it for now. This time I think ugdb is wrong. Oleg.