From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751212AbWF3V6D (ORCPT ); Fri, 30 Jun 2006 17:58:03 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751257AbWF3V6D (ORCPT ); Fri, 30 Jun 2006 17:58:03 -0400 Received: from embla.aitel.hist.no ([158.38.50.22]:42120 "HELO embla.aitel.hist.no") by vger.kernel.org with SMTP id S1751212AbWF3V6B (ORCPT ); Fri, 30 Jun 2006 17:58:01 -0400 Date: Fri, 30 Jun 2006 23:54:05 +0200 To: Andrew Morton Cc: linux-kernel@vger.kernel.org Subject: Re: 2.6.17-mm one process gets stuck in infinite loop in the kernel. Message-ID: <20060630215405.GA9744@aitel.hist.no> References: <20060629013643.4b47e8bd.akpm@osdl.org> <44A3B8A0.4070601@aitel.hist.no> <20060629104117.e96df3da.akpm@osdl.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20060629104117.e96df3da.akpm@osdl.org> User-Agent: Mutt/1.5.11+cvs20060403 From: Helge Hafting Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jun 29, 2006 at 10:41:17AM -0700, Andrew Morton wrote: > On Thu, 29 Jun 2006 13:25:20 +0200 > Helge Hafting wrote: > > > I have seen this both with mm2, m33 and mm4. > > Suddenly, the load meter jumps. > > Using ps & top, I see one process using 100% cpu. > > This is always a process that was exiting, this tend to happen > > when I close applications, or doing debian upgrades which > > runs lots of short-lived processes. > > > > I believe it is running in the kernel, ps lists it with stat "RN" > > and it cannot be killed, not even with kill -9 from root. > > > > Something wrong with process termination? > > > > Please generate a kernel profile when it happens so we can see > where it got stuck. > > > > readprofile -r > sleep 10 > readprofile -n -v -m /boot/System.map | sort -n -k 3 | tail -40 It was easier to reproduce on my home machine, running mm2. I followed the recipe above, except typing manually means the wait was more than 10s. Output from the pipe above: ffffffff801f9050 do_get_write_access 210,0170 ffffffff80111c20 __do_softirq 280,1591 ffffffff8012e0e0 vm_stat_account 280,2917 ffffffff80194890 search_exception_tables 491,5312 ffffffff801f1380 ext3_journal_start_sb 821,0250 ffffffff801fd670 __log_space_left 892,7812 ffffffff8010bf50 __wake_up_bit 1252,6042 ffffffff8010c2f0 put_page 1412,9375 ffffffff8010dd30 mark_page_accessed 1732,1625 ffffffff801a3340 __filemap_copy_from_user_iovec_inatomic 1951,7411 ffffffff801643f0 cond_resched 2001,5625 ffffffff8015f241 error_exit 2431,8409 ffffffff801a5dd0 balance_dirty_pages_ratelimited_nr 2580,5375 ffffffff801f9aa0 journal_start 3211,0559 ffffffff8011ac00 page_waitqueue 3813,9688 ffffffff80139ea0 generic_commit_write 4254,4271 ffffffff80117500 __block_commit_write 4902,3558 ffffffff8010b320 __down_read_trylock 50210,4583 ffffffff8013d100 block_prepare_write 57712,0208 ffffffff80121800 __up_read 5833,3125 ffffffff80117bc0 unlock_page 69214,4167 ffffffff801fd710 journal_blocks_per_page 83426,0625 ffffffff8012e0c0 __wake_up 89427,9375 ffffffff80109d70 kmem_cache_alloc 112617,5938 ffffffff801e78b0 walk_page_buffers 12657,1875 ffffffff801ea920 ext3_ordered_commit_write 13525,2812 ffffffff801074c0 kmem_cache_free 15807,5962 ffffffff801f11e0 __ext3_journal_stop 169617,6667 ffffffff801f96b0 start_this_handle 18711,8562 ffffffff801f8e50 journal_stop 19063,7227 ffffffff801eacf0 ext3_prepare_write 19915,9256 ffffffff80113440 find_lock_page 205314,2569 ffffffff8010f690 generic_file_buffered_write 21391,2612 ffffffff8010deb0 __block_prepare_write 22841,9291 ffffffff801e85c0 ext3_writepage_trans_blocks 279919,4375 ffffffff80166356 bad_gs 33520,4129 ffffffff80179070 search_extable 386834,5357 ffffffff8010b400 find_vma 420137,5089 ffffffff8010a180 do_page_fault 107535,1302 0000000000000000 total 516580,0124