Re: nanosleep truncated on 64 bit Linux by 292 billion years

From: Thomas Gleixner
Date: Tue Oct 28 2014 - 11:45:09 EST


On Mon, 27 Oct 2014, PÃdraig Brady wrote:
> I noticed that nanosleep() on 64 bit, "only" supports 292 years,
> rather than the full potential 292 billion years with 64 bit time_t, due to:
> https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/include/linux/time.h?id=refs/tags/v3.16#n87
>
> Attached is a program from Paul Eggert that illustrates the bug.
> Running this program on a buggy host outputs something like this:
>
> Setting alarm for 1 second from now ...
> Sleeping for 9223372036854775807.999999999 seconds...
> After alarm sent off, remaining time is 9223357678.462306617 seconds;
> i.e., nanosleep claimed that it slept for about 293079448610.606445 years.

I'm aware of the issue. It's on my ever growing todo list.

Thanks,

tglx