Re: [PATCH v2 0/5] fast poll multishot mode

From: Pavel Begunkov
Date: Fri May 06 2022 - 12:02:01 EST


On 5/6/22 15:18, Jens Axboe wrote:
On 5/6/22 1:36 AM, Hao Xu wrote:
Hi All,
I actually had a question about the current poll code, from the code it
seems when we cancel a poll-like request, it will ignore the existing
events and just raise a -ECANCELED cqe though I haven't tested it. Is
this by design or am I missing something?

That's by design, but honestly I don't think anyone considered the case
where it's being canceled but has events already. For that case, I think
we should follow the usual logic of only returning an error (canceled)
if we don't have events, if we have events just return them. For
multi-shot, obviously also terminate, but same logic there.

Why would we care? It's inherently racy in any case and any
user not handling this is already screwed.

--
Pavel Begunkov