Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753211Ab0HQFWL (ORCPT ); Tue, 17 Aug 2010 01:22:11 -0400 Received: from stargate.chelsio.com ([67.207.112.58]:4499 "EHLO stargate.chelsio.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751952Ab0HQFWJ (ORCPT ); Tue, 17 Aug 2010 01:22:09 -0400 Message-ID: <4C6A1C7C.7070004@chelsio.com> Date: Mon, 16 Aug 2010 22:22:04 -0700 From: Dimitris Michailidis Organization: Chelsio Communications User-Agent: Thunderbird 1.5.0.12 (X11/20070530) MIME-Version: 1.0 To: David Miller CC: linux-kernel@vger.kernel.org Subject: Re: tasks getting stuck on mmap_sem? Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1848 Lines: 34 David Miller wrote: > I just started seeing this with current GIT, is it related > to the page table locking shuffle of a few days ago? > > [21029.265646] INFO: task git:16643 blocked for more than 120 seconds. > [21029.267054] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. > [21029.268412] git D 000000000072f804 0 16643 16273 0x210001101000080 > [21029.269809] Call Trace: > [21029.271062] [000000000072f778] rwsem_down_failed_common+0x90/0xb8 > [21029.272390] [000000000072f804] __down_read+0x30/0x40 > [21029.273689] [0000000000731148] do_sparc64_fault+0x238/0x788 > [21029.274996] [00000000004079e8] sparc64_realfault_common+0x10/0x20 > [21029.276347] INFO: task git:16644 blocked for more than 120 seconds. > [21029.277655] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. > [21029.278993] git D 000000000072f874 0 16644 16273 0x210041101000080 > [21029.280348] Call Trace: > [21029.281542] [000000000072f778] rwsem_down_failed_common+0x90/0xb8 > [21029.282818] [000000000072f874] __down_write+0x34/0x44 > [21029.284057] [00000000004d9c44] SyS_mmap_pgoff+0xc8/0x118 > [21029.285293] [0000000000406154] linux_sparc_syscall32+0x34/0x40 > ... > > etc. it's a set of git threads computing deltas for a remote pull > request to the machine. This may be similar to the problems IA-64 had last week as a result of the rwsem changes, eg see commit 01d69a82e1d3c938da16bf55aab000672243aa24. I see arch/sparc/include/asm/atomic_64.h uses ints with atomic64_t, which was a problem for IA-64. Just guessing. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/