Re: 2.6.11-rc1-mm1

[Christoph Hellwig <hch@infradead.org>]

On Mon, Jan 17, 2005 at 10:48:52AM -0500, Robert Wisniewski wrote:
> Wow - disabling interrupts is handfuls to tens of cycles, so that means
> some architectures take thousands of cycles to do atomic operations.  Then
> I would definitely agree we should not be using atomic operations on those,
> fwiw, out of curiosity, what archs make atomic ops so expensive.
> 
> Andrew, on the broader note.  If the community feels disabling interrupts
> is the better way to go for the variables (I think it's index and count) we
> were protecting with atomic ops then as the code stands things should be
> fine with that approach and we can make that change.

The thing I'm unhappy with is what the code does currently.  I haven't
looked at the code enough nor through about the problem enough to tell
you what's the right thing to do.  Knowing that will involve review of
the architecture and serious benchmarking on a few plattforms.