Messages in this thread | | | Date | Mon, 25 Apr 2016 10:26:39 +0200 | From | Peter Zijlstra <> | Subject | Re: [RFC][PATCH 19/31] locking,s390: Implement atomic{,64}_fetch_{add,sub,and,or,xor}() |
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On Mon, Apr 25, 2016 at 10:06:25AM +0200, Martin Schwidefsky wrote: > On Fri, 22 Apr 2016 11:04:32 +0200 > Peter Zijlstra <peterz@infradead.org> 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 irreversible operations -- such as > > bitops (because it becomes impossible to reconstruct the state prior > > to modification). > > > > Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> > > --- > > arch/s390/include/asm/atomic.h | 42 +++++++++++++++++++++++++++++++---------- > > 1 file changed, 32 insertions(+), 10 deletions(-) > > That looks good, the code compiles and the functions are generated correctly. > We will know for sure if it works after the first user of these new functions > hit the kernel.
So we already have an atomic_fetch_or() user in the kernel, and this series adds an atomic_fetch_add_acquire() user.
But yes, we'll undoubtedly grow more over time :-)
> Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Thanks!
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