Subject: Re: yet another SA assertion failure with 3.0
To: Chuck Silvers <chuq@chuq.com>
From: Nathan J. Williams <nathanw@wasabisystems.com>
List: tech-kern
Date: 11/11/2005 12:13:49
Chuck Silvers <chuq@chuq.com> writes:

> > are there any users of these syscalls at all? :-)
> 
> not in our tree.  I don't see why we ever would have any either.
> (other than regression tests to make sure they work.)

Regression testing was definitely the main idea in the first
place. There was some belief at the time that there were a few apps
that could use them (probably WINE, the source of many evil hacks),
but I don't think they materialized.

> > i guess that these syscalls and SA shouldn't share
> > the same "suspended" state.
> 
> I'd rather just allow the SA code to assume that no one else is
> messing with LWP scheduling state by disallowing these operations
> that don't make any sense in an SA context anyway.  that way we
> don't need to think about possible interactions when working on
> the SA code in the future either.

The pthread code uses the _lwp_wakeup() call to assist with
cancellation, but forbidding the rest - maybe not even compiling them
in - seems fine.

        - Nathan