11 Nov
2015
11 Nov
'15
5:44 p.m.
On Wed, Nov 11, 2015 at 12:35:48PM -0500, David Miller wrote:
From: Alexei Starovoitov alexei.starovoitov@gmail.com Date: Wed, 11 Nov 2015 09:27:00 -0800
BPF_XADD == atomic_add() in kernel. period. we are not going to deprecate it or introduce something else.
Agreed, it makes no sense to try and tie C99 or whatever atomic semantics to something that is already clearly defined to have exactly kernel atomic_add() semantics.
... and which is emitted by LLVM when asked to compile __sync_fetch_and_add, which has clearly defined (yet conflicting) semantics.
If the discrepancy is in LLVM (and it sounds like it is), then I'll raise a bug over there instead.
Will