Re: [PATCH v7 01/15] sched/core: uclamp: Add CPU's clamp buckets refcounting

[Peter Zijlstra]

On Thu, Mar 14, 2019 at 11:03:30AM +0000, Patrick Bellasi wrote:

> void uclamp_rq_dec_id(struct rq *rq, int clamp_id, int bucket_id) {
>     if (__builtin_expect(!!(rq->uclamp[clamp_id].bucket[bucket_id].tasks), 1))
>         return;
>     rq->uclamp[clamp_id].bucket[bucket_id].tasks--;
> }
> ---8<---
> 
> generates something like:
> 
> ---8<---
> uclamp_rq_dec_id:
>         sxtw    x1, w1
>         add     x3, x1, x1, lsl 1
>         lsl     x3, x3, 2
>         sub     x3, x3, x1
>         lsl     x3, x3, 2
>         add     x2, x3, x2, sxtw 3
>         add     x0, x0, x2
>         ldr     w1, [x0, 8]
>         cbz     w1, .L4
>         ret
> .L4:
>         mov     w1, -1
>         str     w1, [x0, 8]
>         ret
> ---8<---
> 
> 
> which looks "sane" and quite expected, isn't it?

Yep, thanks! Sometimes I worry about silly things.