From: Pavel Begunkov <asml.silence@gmail.com>
To: Jens Axboe <axboe@kernel.dk>, io-uring <io-uring@vger.kernel.org>
Subject: Re: [PATCH v2] io-wq: handle hashed writes in chains
Date: Sun, 22 Mar 2020 19:24:49 +0300 [thread overview]
Message-ID: <cd8541df-8f97-af3c-ea49-422e546ab648@gmail.com> (raw)
In-Reply-To: <3454f8c1-3d5a-1f94-569a-41e553fc836a@gmail.com>
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On 22/03/2020 19:09, Pavel Begunkov wrote:
> On 19/03/2020 21:56, Jens Axboe wrote:
>> We always punt async buffered writes to an io-wq helper, as the core
>> kernel does not have IOCB_NOWAIT support for that. Most buffered async
>> writes complete very quickly, as it's just a copy operation. This means
>> that doing multiple locking roundtrips on the shared wqe lock for each
>> buffered write is wasteful. Additionally, buffered writes are hashed
>> work items, which means that any buffered write to a given file is
>> serialized.
>>
>> When looking for a new work item, build a chain of identicaly hashed
>> work items, and then hand back that batch. Until the batch is done, the
>> caller doesn't have to synchronize with the wqe or worker locks again.
I have an idea, how to do it a bit better. Let me try it.
--
Pavel Begunkov
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next prev parent reply other threads:[~2020-03-22 16:25 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-19 18:56 [PATCH v2] io-wq: handle hashed writes in chains Jens Axboe
2020-03-22 16:09 ` Pavel Begunkov
2020-03-22 16:24 ` Pavel Begunkov [this message]
2020-03-22 17:08 ` Jens Axboe
2020-03-22 18:54 ` Pavel Begunkov
2020-03-22 19:51 ` Jens Axboe
2020-03-22 20:05 ` Jens Axboe
2020-03-22 20:15 ` Jens Axboe
2020-03-22 20:20 ` Pavel Begunkov
2020-03-22 21:16 ` Pavel Begunkov
2020-03-22 21:31 ` Pavel Begunkov
2020-03-22 20:25 ` Pavel Begunkov
2020-03-23 1:37 ` Jens Axboe
2020-03-23 8:38 ` Pavel Begunkov
2020-03-23 14:26 ` Jens Axboe
2020-03-22 17:08 ` Jens Axboe
2020-03-22 17:37 ` Pavel Begunkov
2020-03-22 20:56 ` Pavel Begunkov
2020-03-23 19:57 Pavel Begunkov
2020-03-24 2:31 ` Jens Axboe
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