On Tue, Mar 15, 2016 at 01:08:35PM +0100, Ingo Molnar wrote: > * Peter Zijlstra <[email protected]> wrote: > > > On Tue, Mar 15, 2016 at 10:32:45AM +0100, Ingo Molnar wrote: > > > 2) its naming sucks. "fetch_or()" does not really signal that it's a > > > fundamentally atomic operation, nor what API family it belongs to. > > > > I disagree there, the fetch-$op naming is widely used for atomic > > operations that return the previous value. See for example the C/C++11 > > atomic ops. > > The problem I see is that we don't really have the fetch_*() naming in the > kernel > right now, while we do have the xchg_*() naming. The latter is 'obviously' an > atomic operation - while 'fetch' could be anything.
We don't have xchg_*() naming, we have xchg() and that's about it. And yes, people know xchg() is an atomic op. But 'fetch (and) or' is also atomic, it has to be, it needs to do 2 operations in 1. Furthermore, the relevant wikipedia page is: https://en.wikipedia.org/wiki/Fetch-and-add So the naming is widely established.
