On 2019-02-12, Linus Torvalds <[email protected]> wrote:
> On Tue, Feb 12, 2019 at 6:30 AM John Ogness <[email protected]> wrote:
>>
>> + while (atomic_long_read(&rb->lost)) {
>> + atomic_long_dec(&rb->lost);
>> + rb->seq++;
>> + }
>
> This looks like crazy garbage. It's neither atomic nor sane.
It works because because only 1 context on a single CPU can hit that
loop. But yes, it is crazy.
> Why isn't it something like
>
> if (atomic_long_read(&rb->lost)) {
> long lost = atomic_xchg(&rb->lost, 0);
> rb->seq += lost;
> }
>
> instead?
Yes, it should be like you suggest. Thanks.
John Ogness
