https://jira.whamcloud.com This file is an XML representation of an issue en-us 9.4.14 940014 05-12-2023 https://jira.whamcloud.com/browse/LU-8418 Lustre <p>A customer reported that LBUG() hit does not always cause a crash dump.<br/> Sometimes the system hangs after LBUG message in the logs.</p> <blockquote><p>No kdump was generated from this crash.</p></blockquote> <p>logs show the panic was not clean; after the LBUG, log messages continue from the node, including cpu soft lockups:</p> <p>Eventually a crash dump was triggered manually through serial console.</p> <p>It showed that the lbug thread hanged in memory allocation while all CPUs are spinning trying to get a spinlock holding by the lbug thread itself.</p> <div class="preformatted panel" style="border-width: 1px;"><div class="preformattedContent panelContent"> <pre>PID: 38035 TASK: ffff880c83804100 CPU: 7 COMMAND: "mdt_446" #0 [ffff880cbaf7d6b0] schedule at ffffffff814ea122 #1 [ffff880cbaf7d778] __cond_resched at ffffffff81061b4a #2 [ffff880cbaf7d798] _cond_resched at ffffffff814eab30 #3 [ffff880cbaf7d7a8] kmem_cache_alloc_notrace at ffffffff8115f385 #4 [ffff880cbaf7d7d8] call_usermodehelper_setup at ffffffff81089e5d #5 [ffff880cbaf7d828] libcfs_run_upcall at ffffffffa04ee9c0 [libcfs] #6 [ffff880cbaf7d8a8] libcfs_run_lbug_upcall at ffffffffa04eed5d [libcfs] #7 [ffff880cbaf7d928] lbug_with_loc at ffffffffa04eee38 [libcfs] #8 [ffff880cbaf7d948] ldlm_export_flock_put at ffffffffa07e137a [ptlrpc] #9 [ffff880cbaf7d968] cfs_hash_bd_del_locked at ffffffffa04ffab1 [libcfs] #10 [ffff880cbaf7d998] cfs_hash_del at ffffffffa0502811 [libcfs] #11 [ffff880cbaf7d9e8] ldlm_flock_blocking_unlink at ffffffffa07e1b82 [ptlrpc] #12 [ffff880cbaf7d9f8] ldlm_process_flock_lock at ffffffffa07e25a2 [ptlrpc] #13 [ffff880cbaf7daf8] ldlm_reprocess_queue at ffffffffa07b6132 [ptlrpc] #14 [ffff880cbaf7db48] ldlm_process_flock_lock at ffffffffa07e265f [ptlrpc] #15 [ffff880cbaf7dc48] ldlm_lock_enqueue at ffffffffa07b7533 [ptlrpc] #16 [ffff880cbaf7dca8] ldlm_handle_enqueue0 at ffffffffa07df0ef [ptlrpc] #17 [ffff880cbaf7dd18] mdt_enqueue at ffffffffa0d18a16 [mdt] #18 [ffff880cbaf7dd38] mdt_handle_common at ffffffffa0d0bffa [mdt] #19 [ffff880cbaf7dd88] mdt_regular_handle at ffffffffa0d0ceb5 [mdt] </pre> </div></div> LU-8418

node fails to kdump after lbug crash

Bug Major Resolved Fixed WC Triage Alexander Zarochentsev patch Wed, 20 Jul 2016 14:40:58 +0000 Sat, 19 Nov 2016 15:50:39 +0000 Sat, 19 Nov 2016 15:50:39 +0000 Lustre 2.8.0 Lustre 2.9.0 0 4 <p>Proposed patch is add ability to disable lnet upcall calling. Currently there is no check that the lnet upcall is set to empty string or to non-existing executable file. I think it is not used in most Lustre setups but the attempt to call it reduces chances of getting a crash dump.<br/> I will upload patch soon.</p> <p>Alexander Zarochentsev (alexander.zarochentsev@seagate.com) uploaded a new patch: <a href="http://review.whamcloud.com/21440" class="external-link" target="_blank" rel="nofollow noopener">http://review.whamcloud.com/21440</a><br/> Subject: <a href="https://jira.whamcloud.com/browse/LU-8418" title="node fails to kdump after lbug crash" class="issue-link" data-issue-key="LU-8418"><del>LU-8418</del></a> libcfs: do not call empty lnet upcall<br/> Project: fs/lustre-release<br/> Branch: master<br/> Current Patch Set: 1<br/> Commit: affe720351475a860925be30511ebe4242651cd2</p> <p>Oleg Drokin (oleg.drokin@intel.com) merged in patch <a href="http://review.whamcloud.com/21440/" class="external-link" target="_blank" rel="nofollow noopener">http://review.whamcloud.com/21440/</a><br/> Subject: <a href="https://jira.whamcloud.com/browse/LU-8418" title="node fails to kdump after lbug crash" class="issue-link" data-issue-key="LU-8418"><del>LU-8418</del></a> libcfs: remove lnet upcall code<br/> Project: fs/lustre-release<br/> Branch: master<br/> Current Patch Set: <br/> Commit: 4bc9bae59fea315bdd36e8170e8388d5fce2a397</p> <p>Landed for 2.9</p> Development Rank 1|hzyhzz: Rank (Obsolete) 9223372036854775807 Severity