[Ksummit-2008-discuss] topic proposal

[Daniel Walker]

On Tue, 2008-08-26 at 18:22 -0600, Matthew Wilcox wrote:
> On Tue, Aug 26, 2008 at 05:05:52PM -0700, Greg KH wrote:
> > On Tue, Aug 26, 2008 at 04:39:10PM -0700, Daniel Walker wrote:
> > > Semaphores do we keep them or do we remove them?
> > > 
> > > I've had enough semaphore removal patches accepted that I think it's
> > > already been decided .. However, it would seem at least Andi and Matthew
> > > don't completely agree .. Which makes me wonder if there's other pockets
> > > of people that either don't know about this, or have specific objections
> > > to it..
> > 
> > Aren't there still a few places in the kernel that want a "counting
> > mutex" that the semaphore code provides?  How is that going to be
> > converted using mutexes?
> 
> Daniel thinks they all have "completion semantics".  Which they don't.
> 

I've seen loads semaphores used as mutexes, and loads used as regular
signaling completions. What remains outside of those two is the wild
un-maintainable stuff that , I think, we really don't want..

I think it's better to define specific use cases for locking and try to
enforce those cases .. Allowing semaphores is like allowing whatever one
off use case someone wants to think up, then we have to try to maintain
it ..

Daniel