Re: [PATCH 2/4] Convert epoll to a bitlock

Andrew Morton
2009-02-03T21:40:46Z

On Mon, 2 Feb 2009 11:20:09 -0700
Jonathan Corbet <corbet@lwn.net> wrote:

> Matt Mackall suggested converting epoll's ep_lock to a bitlock as a way of
> saving space in struct file. This patch makes that change.

hrm. bit_spin_lock() makes people upset (large penguiny people). iirc
it doesn't have all the correct/well-understood memory/compiler
ordering semantics which spinlocks have. And lockdep doesn't know about
it.