4 Sep
2012
4 Sep
'12
10:10 p.m.
Bryan,
To my experience, the assumption 2) is not right. getttimeofday() is implemented in user land in Linux 3 but it is a system call in Linux 2.
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.
Thank you for your correction. To whose who are interested in, additional information can be found from: http://en.chys.info/2009/01/linux%E2%80%99s-vsyscall/ Anyway, I believe we should avoid gettimeofday as much as possible to implement fast servers. --Kazu