<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 12:05, shijunjie92 <<a href="mailto:shijunjie92@gmail.com" class="">shijunjie92@gmail.com</a>> wrote:</div><br class="Apple-interchange-newline"><div 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-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px;" class="">Hello:</div><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-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px;" class=""> </div><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="">The previous pic 'temp.jpg' is snipped from the tutor16's slides<span class="Apple-converted-space"> </span><a href="http://www.litmus-rt.org/tutor16/slides.pdf" class="">http://www.litmus-rt.org/tutor16/slides.pdf</a></div><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="">The 'temp_2.jpg' and 'temp_3.jpg' are snipped from my platform. You can see the gaps in different period are variant and unpredictable.</div><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="">I run the xubuntu img on virtualbox, and the hardware information is listed as follows:</div></div></blockquote><br class=""></div><div>Ok, then this is expected. Virtualization is not transparent with regard to timing. The virtualized OS cannot possibly offer better timing than the underlying hypervisor (+ overheads!).</div><div><br class=""></div><div>The effect that you are seeing should go away (e.g., the gaps should be really, really small) if you run on real hardware.</div><div><br class=""></div><div>- Björn</div><div><br class=""></div><br class=""></body></html>