From: Jens Axboe <axboe@kernel.dk>
To: Josef <josef.grieb@gmail.com>
Cc: Dmitry Kadashev <dkadashev@gmail.com>,
io-uring <io-uring@vger.kernel.org>,
Norman Maurer <norman.maurer@googlemail.com>
Subject: Re: "Cannot allocate memory" on ring creation (not RLIMIT_MEMLOCK)
Date: Sat, 19 Dec 2020 09:29:48 -0700 [thread overview]
Message-ID: <37d4d1fa-a512-c9d0-eaa6-af466adc2a4e@kernel.dk> (raw)
In-Reply-To: <159a8a38-4394-db3b-b7f2-cc26c39caa07@kernel.dk>
On 12/19/20 9:13 AM, Jens Axboe wrote:
> On 12/18/20 7:49 PM, Josef wrote:
>>> I'm happy to run _any_ reproducer, so please do let us know if you
>>> manage to find something that I can run with netty. As long as it
>>> includes instructions for exactly how to run it :-)
>>
>> cool :) I just created a repo for that:
>> https://github.com/1Jo1/netty-io_uring-kernel-debugging.git
>>
>> - install jdk 1.8
>> - to run netty: ./mvnw compile exec:java
>> -Dexec.mainClass="uring.netty.example.EchoUringServer"
>> - to run the echo test: cargo run --release -- --address
>> "127.0.0.1:2022" --number 200 --duration 20 --length 300
>> (https://github.com/haraldh/rust_echo_bench.git)
>> - process kill -9
>>
>> async flag is enabled and these operation are used: OP_READ,
>> OP_WRITE, OP_POLL_ADD, OP_CLOSE, OP_ACCEPT
>>
>> (btw you can change the port in EchoUringServer.java)
>
> This is great! Not sure this is the same issue, but what I see here is
> that we have leftover workers when the test is killed. This means the
> rings aren't gone, and the memory isn't freed (and unaccounted), which
> would ultimately lead to problems of course, similar to just an
> accounting bug or race.
>
> The above _seems_ to be related to IOSQE_ASYNC. Trying to narrow it
> down...
Further narrowed down, it seems to be related to IOSQE_ASYNC on the
read requests. I'm guessing there are cases where we end up not
canceling them on ring close, hence the ring stays active, etc.
If I just add a hack to clear IOSQE_ASYNC on IORING_OP_READ, then
the test terminates fine on the kill -9.
--
Jens Axboe
next prev parent reply other threads:[~2020-12-19 16:30 UTC|newest]
Thread overview: 52+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-17 8:19 "Cannot allocate memory" on ring creation (not RLIMIT_MEMLOCK) Dmitry Kadashev
2020-12-17 8:26 ` Norman Maurer
2020-12-17 8:36 ` Dmitry Kadashev
2020-12-17 8:40 ` Dmitry Kadashev
2020-12-17 10:38 ` Josef
2020-12-17 11:10 ` Dmitry Kadashev
2020-12-17 13:43 ` Victor Stewart
2020-12-18 9:20 ` Dmitry Kadashev
2020-12-18 17:22 ` Jens Axboe
2020-12-18 15:26 ` Jens Axboe
2020-12-18 17:21 ` Josef
2020-12-18 17:23 ` Jens Axboe
2020-12-19 2:49 ` Josef
2020-12-19 16:13 ` Jens Axboe
2020-12-19 16:29 ` Jens Axboe [this message]
2020-12-19 17:11 ` Jens Axboe
2020-12-19 17:34 ` Norman Maurer
2020-12-19 17:38 ` Jens Axboe
2020-12-19 20:51 ` Josef
2020-12-19 21:54 ` Jens Axboe
2020-12-19 23:13 ` Jens Axboe
2020-12-19 23:42 ` Josef
2020-12-19 23:42 ` Pavel Begunkov
2020-12-20 0:25 ` Jens Axboe
2020-12-20 0:55 ` Pavel Begunkov
2020-12-21 10:35 ` Dmitry Kadashev
2020-12-21 10:49 ` Dmitry Kadashev
2020-12-21 11:00 ` Dmitry Kadashev
2020-12-21 15:36 ` Pavel Begunkov
2020-12-22 3:35 ` Pavel Begunkov
2020-12-22 4:07 ` Pavel Begunkov
2020-12-22 11:04 ` Dmitry Kadashev
2020-12-22 11:06 ` Dmitry Kadashev
2020-12-22 13:13 ` Dmitry Kadashev
2020-12-22 16:33 ` Pavel Begunkov
2020-12-23 8:39 ` Dmitry Kadashev
2020-12-23 9:38 ` Dmitry Kadashev
2020-12-23 11:48 ` Dmitry Kadashev
2020-12-23 12:27 ` Pavel Begunkov
2020-12-20 1:57 ` Pavel Begunkov
2020-12-20 7:13 ` Josef
2020-12-20 13:00 ` Pavel Begunkov
2020-12-20 14:19 ` Pavel Begunkov
2020-12-20 15:56 ` Josef
2020-12-20 15:58 ` Pavel Begunkov
2020-12-20 16:14 ` Jens Axboe
2020-12-20 16:59 ` Josef
2020-12-20 18:23 ` Josef
2020-12-20 18:41 ` Pavel Begunkov
2020-12-21 8:22 ` Josef
2020-12-21 15:30 ` Pavel Begunkov
2020-12-21 10:31 ` Dmitry Kadashev
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