<html><head><meta http-equiv="Content-Type" content="text/html charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><br class=""><div><blockquote type="cite" class=""><div class="">On May 11, 2017, at 1:33 PM, Pavol Vaskovic via swift-dev <<a href="mailto:swift-dev@swift.org" class="">swift-dev@swift.org</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><div class="" style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px;">Douglas Gregor suggested in SR-4814 (that was merged as dupe into SR-4669) that I get in contact with you because I’m working on issue <a href="https://bugs.swift.org/browse/SR-4669" class="">SR-4669 Add a Benchmark_Driver --rerun N option</a> and I should make sure that I don’t break the Swift-CI.</div><div class="" style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px;"><br class=""></div><div class="" style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px;">The point of that is to deal with false changes (regressions and improvements) that are often seen in benchmark reports from CI.</div><div class="" style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px;"><br class=""></div><div class="" style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px;">I have run Benchmark_O with --num-iters=100 on my machine for the the whole performance test suite, to get a feeling for the distribution of benchmark samples, because I also want to move the Benchmark_Driver to use MEAN instead of MIN in the analysis.</div></div></blockquote></div><br class=""><div class="">Using MEAN wasn’t part of the aforementioned SR-4669. The purpose of that task is to reduce the time CI takes to get useful results (e.g. by using 3 runs as a baseline). MEAN isn’t useful if you’re only gathering 3 data points.</div><div class=""><br class=""></div><div class="">-Andy</div></body></html>