Re: [PATCH] block: switch to atomic_t for request references

Peter Zijlstra
2021-12-07T10:30:46Z

On Mon, Dec 06, 2021 at 04:13:00PM -0800, Linus Torvalds wrote:

> IOW, I think that "try_get_page()" function is basically the *much*
> superior version of what is currently a broken "refcount_inc()".
>
> And yes, it does warn about that overflow case that you claim only
> refcount_t does. And does so without the broken semantics that
> refcount h as.

That places the burden of the unlikely overflow case on the user. Now
every driver author needs to consider the overflow case and have a
corresponding error path. How many bugs will that introduce?

Why is saturation; iow. leaking the memory, a worse option than having
bad/broken/never-tested error paths all over the kernel?