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-13386 Lustre <p>ll_ra_count_get() is designed to allow over reservation for performance reasons, this could happen that multiple threads consuming a small readahead window limit, it will fallback to small 4K read which hurts performances.</p> LU-13386

allow over reservation to cover current read

Bug Minor Resolved Fixed Wang Shilong Wang Shilong Wed, 25 Mar 2020 01:58:14 +0000 Fri, 10 Apr 2020 12:43:09 +0000 Tue, 7 Apr 2020 18:10:45 +0000 Lustre 2.14.0 0 3 <p>Wang Shilong (wshilong@ddn.com) uploaded a new patch: <a href="https://review.whamcloud.com/38047" class="external-link" target="_blank" rel="nofollow noopener">https://review.whamcloud.com/38047</a><br/> Subject: <a href="https://jira.whamcloud.com/browse/LU-13386" title="allow over reservation to cover current read" class="issue-link" data-issue-key="LU-13386"><del>LU-13386</del></a> readahead: fix to allow over reservation to cover current read<br/> Project: fs/lustre-release<br/> Branch: master<br/> Current Patch Set: 1<br/> Commit: f67bfe62dbd91b965ca59a8978eafdbc84c71c6f</p> <p>Oleg Drokin (green@whamcloud.com) merged in patch <a href="https://review.whamcloud.com/38047/" class="external-link" target="_blank" rel="nofollow noopener">https://review.whamcloud.com/38047/</a><br/> Subject: <a href="https://jira.whamcloud.com/browse/LU-13386" title="allow over reservation to cover current read" class="issue-link" data-issue-key="LU-13386"><del>LU-13386</del></a> llite: allow current readahead to exceed reservation<br/> Project: fs/lustre-release<br/> Branch: master<br/> Current Patch Set: <br/> Commit: 777b04a09356afe425e9dc3dd3de385109990b52</p> <p>Please also backport to b2_12.  Thanks!</p> <p>Don't worry <a href="https://jira.whamcloud.com/secure/ViewProfile.jspa?name=dauchy" class="user-hover" rel="dauchy">dauchy</a> we do have a process to track this kind of thing (though admittedly it usually takes longer than 30 mins <img class="emoticon" src="https://jira.whamcloud.com/images/icons/emoticons/wink.png" height="16" width="16" align="absmiddle" alt="" border="0"/> )</p> <p>I checked that b2_12 did not backport:</p> <p><a href="https://jira.whamcloud.com/browse/LU-12043" title="improve Lustre single thread read performances" class="issue-link" data-issue-key="LU-12043"><del>LU-12043</del></a> llite: make sure readahead cover current read</p> <p>So we don't need the patch to b2_12 branch unless above patch ported to b2_12 firstly.</p> Related LU-12043 Development Rank 1|i00w9b: Rank (Obsolete) 9223372036854775807 Severity