From: Jens Axboe <axboe@kernel.dk>
To: Pavel Begunkov <asml.silence@gmail.com>, io-uring@vger.kernel.org
Subject: Re: [PATCH 0/6] 5.9 small cleanups/fixes
Date: Fri, 31 Jul 2020 09:10:19 -0600 [thread overview]
Message-ID: <d894ebc4-2e54-3eb5-ba21-dff42b022e7f@kernel.dk> (raw)
In-Reply-To: <ccea0f83-8ef3-018f-a590-ef8fad255b94@gmail.com>
On 7/31/20 8:28 AM, Pavel Begunkov wrote:
> On 30/07/2020 21:08, Jens Axboe wrote:
>> On 7/30/20 9:43 AM, Pavel Begunkov wrote:
>>> [1/1] takes apart the union, too much trouble and there is no reason
>>> left for keeping it. Probably for 5.10 we can reshuffle the layout as
>>> discussed.
>>
>> Let's hope so, because I do think this is the safest option, but it does
>> incur a 5% drop for me.
>
> Hmm, any ideas why? If your test doesn't use neither apoll/poll/io-wq,
> then it looks like either something related to slab (e.g. partial zeroing),
> or magic with @task_work moved from 4th to 3rd cacheline.
Was looking into it just now, but I think it was just a bad test run. Checked
out and ran a new test, and then just with #1 applied which would be the only
one that should impact things. And it's pretty close, so I'm going to call
it a wash.
So nothing to worry about I think.
--
Jens Axboe
prev parent reply other threads:[~2020-07-31 15:10 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-30 15:43 [PATCH 0/6] 5.9 small cleanups/fixes Pavel Begunkov
2020-07-30 15:43 ` [PATCH 1/6] io_uring: de-unionise io_kiocb Pavel Begunkov
2020-07-30 15:43 ` [PATCH 2/6] io_uring: deduplicate __io_complete_rw() Pavel Begunkov
2020-07-30 15:43 ` [PATCH 3/6] io_uring: fix racy overflow count reporting Pavel Begunkov
2020-07-30 17:18 ` Jens Axboe
2020-07-30 17:33 ` Pavel Begunkov
2020-07-30 17:41 ` Jens Axboe
2020-07-30 15:43 ` [PATCH 4/6] io_uring: fix stalled deferred requests Pavel Begunkov
2020-07-30 15:43 ` [PATCH 5/6] io_uring: consolidate *_check_overflow accounting Pavel Begunkov
2020-07-30 15:43 ` [PATCH 6/6] io_uring: get rid of atomic FAA for cq_timeouts Pavel Begunkov
2020-07-30 18:08 ` [PATCH 0/6] 5.9 small cleanups/fixes Jens Axboe
2020-07-31 14:28 ` Pavel Begunkov
2020-07-31 15:10 ` Jens Axboe [this message]
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