From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Sun, 12 May 2002 18:48:52 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Sun, 12 May 2002 18:48:51 -0400 Received: from ep09.kernel.pl ([212.87.11.162]:28293 "EHLO ep09.kernel.pl") by vger.kernel.org with ESMTP id ; Sun, 12 May 2002 18:48:48 -0400 Message-ID: <007201c1fa07$2d7bd5d0$0201a8c0@witek> From: "Witek Krecicki" To: "Manfred Spraul" Cc: In-Reply-To: <3CDED21B.3050208@colorfullife.com> Subject: Re: [BUG 2.5.X] Hollow processes Date: Mon, 13 May 2002 00:48:46 +0200 MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2600.0000 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2600.0000 X-AntiVirus: scanned for viruses by AMaViS 0.2.1 (http://amavis.org/) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org ----- Original Message ----- From: "Manfred Spraul" > > It's impossible to check what the process is (trying to read > > /proc/{pid}/{anyting} causes reading process to hang in the > > same way (so we have now 2 hanging processes). > > Have you tried SysRQ+showTasks? That dumps the kernel stack. You can > convert the numbers to names with ksymoops, or often klogd will convert > them and the result is in /var/log/messages. > > What exactly hangs? > Could you run > > strace ls /proc/1234 > strace cat /proc/1234/maps > strace ls /proc/1234/fd -l > > Which syscall hangs? > SMP or UP? It's UP machine with UP kernel. I haven't tried it now strace'ing 'cat /proc/1234/cmdline' (on 2.5.15) but as I remember from earlier kernels it hanged on file reading processes. I'll try to make some additional tests as soon as I'll be back from short vacation ls'ing /proc/1234 doesn't hangs but ls -al does. BTW: from my earlier post: mremap(0x407c5000, 8192, 12288, MREMAP_MAYMOVE) = 0x407c1000 brk(0x82e5000) = 0x82e5000 brk(0x82e6000) = 0x82e6000 old_mmap(NULL, 135168, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x407dc000 mremap(0x407ce000, 8192, 12288, MREMAP_MAYMOVE This is strace poldek on 2.5.11 kernel (behaviour is the same) WK P.S. now I can't reproduce it (on 2.5.15) as it's glibc compilation and it takes far too long and has many subprocesses, but poldek issue on 2.5.11/12 was reproductible. WK