Re: [PATCH] hrtimers: Special-case zero length sleeps
[Posted February 17, 2012 by corbet]
| From: |
| Matthew Garrett <mjg59-AT-srcf.ucam.org> |
| To: |
| Thomas Gleixner <tglx-AT-linutronix.de> |
| Subject: |
| Re: [PATCH] hrtimers: Special-case zero length sleeps |
| Date: |
| Thu, 16 Feb 2012 14:27:33 +0000 |
| Message-ID: |
| <20120216142733.GA15632@srcf.ucam.org> |
| Cc: |
| LKML <linux-kernel-AT-vger.kernel.org>,
Arjan van de Ven <arjan-AT-infradead.org>,
Peter Zijlstra <peterz-AT-infradead.org> |
| Archive‑link: | |
Article |
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
