On Wed, Oct 15, 2014 at 12:06 AM, Merlin Moncure <
mmoncure@gmail.com> wrote:
>
> A while back, I submitted a minor tweak to the clock sweep so that,
> instead of spinlocking every single buffer header as it swept it just
> did a single TAS as a kind of a trylock and punted to the next buffer
> if the test failed on the principle there's not good reason to hang
> around. You only spin if you passed the first test; that should
> reduce the likelihood of actual spinning to approximately zero. I
> still maintain there's no reason not to do that (I couldn't show a
> benefit but that was because mapping list locking was masking any
> clock sweep contention at that time).
If you feel that can now show the benefit, then I think you can rebase
it for the coming commit fest (which is going to start today).