On Fri, Jun 17, 2005 at 06:35:16PM +1000, Nick Piggin wrote: > William Lee Irwin III wrote: > > > > >I'd feel far more comfortable with this if the lockbit resided in the > >page. Also, compare it to akpm's solution. > > > > akpm's solution is alright. They perform similarly on the workload in > question. Of course, the bitlock will scale quite a lot better if you > pushed it and will automatically be localised per device and have NUMA > locality, etc.
The buffer head is not necessarily NUMA local though - there is some chance that a BH from a different node is reused. struct page is guaranteed to be node local of the memory. > > As far as page flags go - I agree but I didn't want to use one up. > This is very localised and I don't think it is particularly worse > than what was there before, so I think we can get away with it for > the moment. I'm starting to think that we need different strategies on 32bit and 64bit here. 64bit has plenty of bits left; it is just 32bit that is a problem here. -Andi
