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-6371 Lustre <p>A program using sendfile to copy a file from lustre to lustre, with a group lock on its source will see the transfer split in tiny chunks.</p> <p>Reproducer attached.</p> <p>Test setup. Create a 100MiB file.</p> <div class="preformatted panel" style="border-width: 1px;"><div class="preformattedContent panelContent"> <pre>$ pwd /mnt/lustre $ dd if=/dev/zero of=foo1 bs=1M count=100 </pre> </div></div> <p>Transfer without a group lock:</p> <div class="preformatted panel" style="border-width: 1px;"><div class="preformattedContent panelContent"> <pre>$ strace ~/lustre-cleanup/lustre/tests/llsendfile4 0 foo1 foo2 ... sendfile(4, 3, NULL, 10485760) = 10485760 sendfile(4, 3, NULL, 10485760) = 10485760 sendfile(4, 3, NULL, 10485760) = 10485760 sendfile(4, 3, NULL, 10485760) = 10485760 sendfile(4, 3, NULL, 10485760) = 10485760 sendfile(4, 3, NULL, 10485760) = 10485760 ... </pre> </div></div> <p>With a group lock</p> <div class="preformatted panel" style="border-width: 1px;"><div class="preformattedContent panelContent"> <pre>$ strace ~/lustre-cleanup/lustre/tests/llsendfile4 1223 foo1 foo2 ... sendfile(4, 3, NULL, 10485760) = 28672 sendfile(4, 3, NULL, 10485760) = 4096 sendfile(4, 3, NULL, 10485760) = 4096 sendfile(4, 3, NULL, 10485760) = 8192 sendfile(4, 3, NULL, 10485760) = 4096 sendfile(4, 3, NULL, 10485760) = 4096 sendfile(4, 3, NULL, 10485760) = 4096 ... </pre> </div></div> <p>The second example takes about 10 times longer than the first.</p> LU-6371

sendfile with group lock splits transfer into tiny chunks

Bug Major Resolved Duplicate WC Triage Frank Zago Mon, 16 Mar 2015 21:25:11 +0000 Sun, 30 Jan 2022 10:48:51 +0000 Sun, 30 Jan 2022 10:48:51 +0000 Lustre 2.7.0 0 8 <p>Frank reported to me that the patch for <a href="https://jira.hpdd.intel.com/browse/LU-6368" class="external-link" target="_blank" rel="nofollow noopener">https://jira.hpdd.intel.com/browse/LU-6368</a> fixes this issue.</p> <p>Honestly, I have no idea why. I'll try to understand why and report back.</p> <p>It's good for you guys to run test for sendfile cases. Is it possible to generate a few test cases and add them into sanity?</p> <p>Thanks,</p> <p>Yes, I'll add some tests too.</p> <p>The patch in question is <a href="http://review.whamcloud.com/14093" class="external-link" target="_blank" rel="nofollow noopener">http://review.whamcloud.com/14093</a></p> Related LU-6368 Development Rank 1|hzx8mf: Rank (Obsolete) 9223372036854775807 Severity