On Thu, Oct 20, 2016 at 2:00 PM, Richard Henderson <r...@twiddle.net> wrote: > On 10/20/2016 10:51 AM, Pranith Kumar wrote: >>> >>> Added back >>> >>> /* Load/Store exclusive instructions are implemented by remembering >>> the value/address loaded, and seeing if these are the same >>> when the store is performed. This should be sufficient to implement >>> the architecturally mandated semantics, and avoids having to monitor >>> regular stores. The compare vs the remembered value is done during >>> the cmpxchg operation, but we must compare the addresses manually. */ >>> >> >> FYI, I do not see this in your v7 series. > > > I do. It's in patch 28: > > /* Load/Store exclusive instructions are implemented by remembering > the value/address loaded, and seeing if these are the same > - when the store is performed. This should be sufficient to implement > + when the store is performed. This should be sufficient to implement > the architecturally mandated semantics, and avoids having to monitor > - regular stores. > - > - In system emulation mode only one CPU will be running at once, so > - this sequence is effectively atomic. In user emulation mode we > - throw an exception and handle the atomic operation elsewhere. */ > + regular stores. The compare vs the remembered value is done during > + the cmpxchg operation, but we must compare the addresses manually. */ >
Indeed, I was looking at atomic-6 on github. atomic-7 is not there yet :) Thanks, -- Pranith
