On 10/10/24 10:20, Ruyi Zhang wrote:
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On 25 Sep 2024 12:58 Pavel Begunkov wrote
On 9/25/24 09:58, Ruyi Zhang wrote:
io_uring fdinfo contains most of the runtime information,which is
helpful for debugging io_uring applications; However, there is
currently a lack of timeout-related information, and this patch adds
timeout_list information.
Please refer to unaddressed comments from v1. We can't have irqs
disabled for that long. And it's too verbose (i.e. depends on
the number of timeouts).
Two questions:
1. I agree with you, we shouldn't walk a potentially very long list
under spinlock. but i can't find any other way to get all the timeout
If only it's just under the spin, but with disabled irqs...
information than to walk the timeout_list. Do you have any good ideas?
In the long run it'd be great to replace the spinlock
with a mutex, i.e. just ->uring_lock, but that would might be
a bit involving as need to move handling to the task context.
2. I also agree seq_printf heavier, if we use seq_put_decimal_ull and
seq_puts to concatenate strings, I haven't tested whether it's more
efficient or not, but the code is certainly not as readable as the
former. It's also possible that I don't fully understand what you mean
and want to hear your opinion.
I don't think there is any difference, it'd be a matter of
doubling the number of in flight timeouts to achieve same
timings. Tell me, do you really have a good case where you
need that (pretty verbose)? Why not drgn / bpftrace it out
of the kernel instead?
--
Pavel Begunkov
