Re: [RFC][PATCH 04/31] locking,arm: Implement atomic{,64}_fetch_{add,sub,and,andnot,or,xor}{,_relaxed,_acquire,_release}()

2016-04-22 Thread Will Deacon
On Fri, Apr 22, 2016 at 11:04:17AM +0200, Peter Zijlstra wrote: > Implement FETCH-OP atomic primitives, these are very similar to the > existing OP-RETURN primitives we already have, except they return the > value of the atomic variable _before_ modification. > > This is especially useful for

Re: [RFC][PATCH 04/31] locking,arm: Implement atomic{,64}_fetch_{add,sub,and,andnot,or,xor}{,_relaxed,_acquire,_release}()

2016-04-22 Thread Will Deacon
On Fri, Apr 22, 2016 at 11:04:17AM +0200, Peter Zijlstra wrote: > Implement FETCH-OP atomic primitives, these are very similar to the > existing OP-RETURN primitives we already have, except they return the > value of the atomic variable _before_ modification. > > This is especially useful for

[RFC][PATCH 04/31] locking,arm: Implement atomic{,64}_fetch_{add,sub,and,andnot,or,xor}{,_relaxed,_acquire,_release}()

2016-04-22 Thread Peter Zijlstra
Implement FETCH-OP atomic primitives, these are very similar to the existing OP-RETURN primitives we already have, except they return the value of the atomic variable _before_ modification. This is especially useful for irreversible operations -- such as bitops (because it becomes impossible to

[RFC][PATCH 04/31] locking,arm: Implement atomic{,64}_fetch_{add,sub,and,andnot,or,xor}{,_relaxed,_acquire,_release}()

2016-04-22 Thread Peter Zijlstra
Implement FETCH-OP atomic primitives, these are very similar to the existing OP-RETURN primitives we already have, except they return the value of the atomic variable _before_ modification. This is especially useful for irreversible operations -- such as bitops (because it becomes impossible to