F-ckin Leap Seconds, how do they work?

Bryan Horstmann-Allen bdha at mirrorshades.net
Tue Jul 3 08:41:21 UTC 2012

| On 2012-07-03 17:27:14, Matthew Palmer wrote:
| The problems I saw were related to programs that use futex(2) (Java, MySQL,
| Chromium, in my personal experience) chewing up lots of CPU because the
| futex system call wasn't quite doing what it was supposed to be doing
| (waking up threads when they were OK to proceed) and instead constantly
| waking the threads up, having the threads go "OK, so my lock is clear and
| I'm ready to go?", the kernel saying "oh, no, sorry" and the thread going
| back to sleep again -- only to be woken up again immediately.  Sort of an
| object lesson in why busy-wait locks suck.

A good dig into the problem, and previous problems with that code:


cyberpunk is dead. long live cyberpunk.

More information about the NANOG mailing list