在 2021/2/5 上午12:48, Pavel Begunkov 写道:
On 03/02/2021 01:48, Jens Axboe wrote:
On 2/2/21 5:04 PM, Pavel Begunkov wrote:
On 02/02/2021 19:52, Hao Xu wrote:
This might happen if we do epoll_wait on a uring fd while reading/writing
the former epoll fd in a sqe in the former uring instance.
So let's don't flush cqring overflow list when we fail to get the uring
lock. This leads to less accuracy, but is still ok.
if (io_cqring_events(ctx) || test_bit(0, &ctx->cq_check_overflow))
mask |= EPOLLIN | EPOLLRDNORM;
Instead of flushing. It'd make sense if we define poll as "there might
be something, go do your peek/wait with overflow checks". Jens, is that
documented anywhere?
Nope - I actually think that the approach chosen here is pretty good,
it'll force the app to actually check and hence do what it needs to do.
Ok, seems we agree on that.
Hao, can you send an updated patch?
Sure, will send v2 soon.
