On Sun, Sep 2, 2012 at 7:56 PM, Kazu Yamamoto <span dir="ltr"><<a href="mailto:kazu@iij.ad.jp" target="_blank">kazu@iij.ad.jp</a>></span> wrote:<br><div class="gmail_quote"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div id=":lb">To my experience, the assumption 2) is not right. getttimeofday()<br>
is implemented in user land in Linux 3 but it is a system call<br>
in Linux 2.<br></div></blockquote></div><br><div>Just a nit: your history here is not correct. gettimeofday has been implemented as a vsyscall for a long time, maybe 5 years. And while it's faster than int 0x80, it's not that much faster: 2x or so on modern hardware.</div>