Re: [PATCH] hrtimers: Special-case zero length sleeps

Matthew Garrett
2012-02-16T14:27:39Z

On Wed, Feb 15, 2012 at 08:47:57PM +0000, Matthew Garrett wrote:

> Ok. I'll work on finding how prevelant it is and see if we can kill it
> off in userspace.

Checking through an exploded Fedora kernel tree suggests around 125
packages out of 11000 or so, so around 1% of userspace seems to use
sleep(0) under certain circumstances. We can probably fix everything in
the distribution, but that suggests that there's also going to be a
significant amount of code in the outside world that's also broken.

Userspace clearly has an expectation that sleep(0) is magic in some
ill-defined way. We'd be well within our rights to break that
expectation, but I think it's common enough to warrant special casing.

--
Matthew Garrett | mjg59@srcf.ucam.org