On 11/1/24 10:59 AM, Pavel Begunkov wrote: > On 10/31/24 21:22, Jens Axboe wrote: >> In hindsight everything is clearer, but it probably should've been known >> that 8 bits of ->flags would run out sooner than later. Rather than >> gobble up the last bit for a random use case, add a bit that controls >> whether or not ->personality is used as a flags2 argument. If that is >> the case, then there's a new IOSQE2_PERSONALITY flag that tells io_uring >> which personality field to read. >> >> While this isn't the prettiest, it does allow extending with 15 extra >> flags, and retains being able to use personality with any kind of >> command. The exception is uring cmd, where personality2 will overlap >> with the space set aside for SQE128. If they really need that, then that >> would have to be done via a uring cmd flag. > > Interesting, I was just experimenting using the personality bits for > similar purposes I mentioned but in a different way, and I even thought > if anything it could be used to extend sqe flags though I'm not a huge > fan of that. We're going to need more SQE flags at some point. At least with the potential to extend it with a setup flag in the future, we can grab the last one and have that other option down the line. I don't mind grabbing personality. Obviously it'd be better to get free space somewhere, but there's no free real estate... -- Jens Axboe
