<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 19 Jul 2016, at 11:13, shijunjie92 <<a href="mailto:shijunjie92@gmail.com" class="">shijunjie92@gmail.com</a>> wrote:</div><div class=""><br class=""><div style="font-family: 'times new roman'; font-size: 14px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-indent: 2em;" class="">When I use the feature trace tool to draw the Gantt chart of the cpus' execution. I notice that there is a gap between the release time and the beginning of the real execution. I have traced the code of 'rtspin.c' but found nothing. Can anyone explain the reason of the random gap or how to reduce the gap? (sometimes the gap is 2 ms)</div></div></blockquote></div><br class=""><div class="">That’s release latency. Either your platform’s timers are extremely imprecise (this is usually the case under virtualization), or you have extremely long non-preemptive sections, or there is some extreme overhead. In mainline LITMUS^RT (with a normal config), I would rule out the last two issues.</div><div class=""><br class=""></div><div class="">What hardware platform are you running your test on? This looks like a trace from a VM to me.</div><div class=""><br class=""></div><div class="">- Björn</div><div class=""><br class=""></div></body></html>