Re: [PATCH] block: switch to atomic_t for request references
From: Peter Zijlstra <peterz@infradead.org>
Date: 2021-12-07 10:30:46
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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?