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-82 Lustre <p>It seems that top locks cache is not killing locks that don't have any valid sublocks left, so this cache for actively used files grows to tens of locks easily slowing everything down.<br/> To make things worse, sometimes these useless locks are matched against really wanted locks, but the cached lock is wider, so we try to enqueue a lock much wider than we actually need which leads to even more of a slowdown with shared file access.</p> LU-82

CLIO lock cache caching useless locks

Bug Critical Resolved Fixed Jinshan Xiong Oleg Drokin Wed, 9 Feb 2011 13:24:30 +0000 Tue, 27 Nov 2012 16:10:09 +0000 Tue, 27 Nov 2012 16:10:09 +0000 Lustre 2.0.0 Lustre 2.1.0 Lustre 2.1.0 0 0 <p>patch is at: <a href="http://review.whamcloud.com/227" class="external-link" target="_blank" rel="nofollow noopener">http://review.whamcloud.com/227</a></p> <p>Reassign to Jay since he is working on it.</p> <p>Let me describe this problem a little bit in detail so as to help inspect.</p> <p>The root cause of this problem is due to the handling inside cl_lock_request(), where:</p> <p> rc = cl_enqueue_locked(env, lock, io, enqflags);<br/> if (rc == 0) {<br/> if (cl_lock_fits_into(env, lock, need, io)) </p> { cl_lock_mutex_put(env, lock); cl_lock_lockdep_acquire(env, lock, enqflags); break; } <p> cl_unuse_locked(env, lock);</p> <p>If a lock was matched but it turns out to not fit after queuing(this may happen if there is a race that the sublock was canceled, and then a new sublock is created), cl_unuse_locked will put the lock into CLS_NEW state. Some time later, when the sublock of this lock is canceled, it won't delete the top lock because its state is CLS_NEW. The new patch just does it.</p> <p>Integrated in <span class="image-wrap" style=""><img src="http://build.whamcloud.com/images/16x16/blue.png" style="border: 0px solid black" /></span> <a href="http://build.whamcloud.com/job/reviews-centos5/407/" class="external-link" target="_blank" rel="nofollow noopener">reviews-centos5 #407</a><br/> <a href="https://jira.whamcloud.com/browse/LU-82" title="CLIO lock cache caching useless locks" class="issue-link" data-issue-key="LU-82"><del>LU-82</del></a> Remove useless clio locks</p> <p>Jinshan Xiong : <a href="http://git.whamcloud.com/gitweb/?p=fs/lustre-release.git&amp;a=commit&amp;h=296923908584532e581b71a7f9d8a6c6e8b7c8dd" class="external-link" target="_blank" rel="nofollow noopener">296923908584532e581b71a7f9d8a6c6e8b7c8dd</a><br/> Files : </p> <ul> <li>lustre/lov/lovsub_lock.c</li> </ul> <p>resubmit the patch to <a href="http://review.whamcloud.com/#change,305" class="external-link" target="_blank" rel="nofollow noopener">http://review.whamcloud.com/#change,305</a></p> <p>passed acc-sm test on lab machines.</p> <p>Integrated in <span class="image-wrap" style=""><img src="http://build.whamcloud.com/images/16x16/blue.png" style="border: 0px solid black" /></span> <a href="http://build.whamcloud.com/job/reviews-centos5/465/" class="external-link" target="_blank" rel="nofollow noopener">reviews-centos5 #465</a><br/> <a href="https://jira.whamcloud.com/browse/LU-82" title="CLIO lock cache caching useless locks" class="issue-link" data-issue-key="LU-82"><del>LU-82</del></a> Remove useless clio locks</p> <p>Jinshan Xiong : <a href="http://git.whamcloud.com/gitweb/?p=fs/lustre-release.git&amp;a=commit&amp;h=03d3bfd55dc9598b96846eb87628addaf8b5f3de" class="external-link" target="_blank" rel="nofollow noopener">03d3bfd55dc9598b96846eb87628addaf8b5f3de</a><br/> Files : </p> <ul> <li>lustre/lov/lovsub_lock.c</li> </ul> <p>Integrated in <span class="image-wrap" style=""><img src="http://build.whamcloud.com/images/16x16/blue.png" style="border: 0px solid black" /></span> <a href="http://build.whamcloud.com/job/lustre-master-centos5/149/" class="external-link" target="_blank" rel="nofollow noopener">lustre-master-centos5 #149</a><br/> <a href="https://jira.whamcloud.com/browse/LU-82" title="CLIO lock cache caching useless locks" class="issue-link" data-issue-key="LU-82"><del>LU-82</del></a> Remove useless clio locks</p> <p>Oleg Drokin : <a href="http://git.whamcloud.com/gitweb/?p=fs/lustre-release.git&amp;a=commit&amp;h=fa507031d245b08c7f24efed32819daf2aa42ab3" class="external-link" target="_blank" rel="nofollow noopener">fa507031d245b08c7f24efed32819daf2aa42ab3</a><br/> Files : </p> <ul> <li>lustre/lov/lovsub_lock.c</li> </ul> <p>Integrated in <span class="image-wrap" style=""><img src="http://build.whamcloud.com/images/16x16/red.png" style="border: 0px solid black" /></span> <a href="http://build.whamcloud.com/job/reviews-rhel6/32/" class="external-link" target="_blank" rel="nofollow noopener">reviews-rhel6 #32</a><br/> <a href="https://jira.whamcloud.com/browse/LU-82" title="CLIO lock cache caching useless locks" class="issue-link" data-issue-key="LU-82"><del>LU-82</del></a> Remove useless clio locks</p> <p>Oleg Drokin : <a href="http://git.whamcloud.com/gitweb/?p=fs/lustre-dev.git&amp;a=commit&amp;h=fa507031d245b08c7f24efed32819daf2aa42ab3" class="external-link" target="_blank" rel="nofollow noopener">fa507031d245b08c7f24efed32819daf2aa42ab3</a><br/> Files : </p> <ul> <li>lustre/lov/lovsub_lock.c</li> </ul> <p>Integrated in <span class="image-wrap" style=""><img src="http://build.whamcloud.com/images/16x16/blue.png" style="border: 0px solid black" /></span> <a href="http://build.whamcloud.com/job/reviews-centos5/482/" class="external-link" target="_blank" rel="nofollow noopener">reviews-centos5 #482</a><br/> <a href="https://jira.whamcloud.com/browse/LU-82" title="CLIO lock cache caching useless locks" class="issue-link" data-issue-key="LU-82"><del>LU-82</del></a> Remove useless clio locks</p> <p>Oleg Drokin : <a href="http://git.whamcloud.com/gitweb/?p=fs/lustre-release.git&amp;a=commit&amp;h=fa507031d245b08c7f24efed32819daf2aa42ab3" class="external-link" target="_blank" rel="nofollow noopener">fa507031d245b08c7f24efed32819daf2aa42ab3</a><br/> Files : </p> <ul> <li>lustre/lov/lovsub_lock.c</li> </ul> Development Rank 1|hzv36n: Rank (Obsolete) 4015 Severity