Re: [PATCHv2 05/16] atomics: prepare for atomic64_fetch_add_unless()

[Michael Ellerman <mpe@ellerman.id.au>]

Mark Rutland <mark.rutland@arm.com> writes:

> On Tue, Jun 05, 2018 at 08:54:03PM +1000, Michael Ellerman wrote:
>> Mark Rutland <mark.rutland@arm.com> writes:
>> > On Tue, Jun 05, 2018 at 11:26:37AM +0200, Peter Zijlstra wrote:
>> >> On Tue, May 29, 2018 at 04:43:35PM +0100, Mark Rutland wrote:
>> >> >  /**
>> >> > + * atomic64_add_unless - add unless the number is already a given value
>> >> > + * @v: pointer of type atomic_t
>> >> > + * @a: the amount to add to v...
>> >> > + * @u: ...unless v is equal to u.
>> >> > + *
>> >> > + * Atomically adds @a to @v, so long as @v was not already @u.
>> >> > + * Returns non-zero if @v was not @u, and zero otherwise.
>> >> 
>> >> I always get confused by that wording; would something like: "Returns
>> >> true if the addition was done" not be more clear?
>> >
>> > Sounds clearer to me; I just stole the wording from the existing
>> > atomic_add_unless().
>> >
>> > I guess you'll want similar for the conditional inc/dec ops, e.g.
>> >
>> > /**
>> >  * atomic_inc_not_zero - increment unless the number is zero
>> >  * @v: pointer of type atomic_t
>> >  *
>> >  * Atomically increments @v by 1, so long as @v is non-zero.
>> >  * Returns non-zero if @v was non-zero, and zero otherwise.
>> >  */
>> 
>> If we're bike-shedding .. :)
>> 
>> I think "so long as" is overly wordy and not helpful. It'd be clearer
>> just as:
>> 
>>   * Atomically increments @v by 1, if @v is non-zero.
>
> I agree; done.

Thanks.

cheers