From: Jens Axboe <axboe@kernel.dk>
To: Yin Fengwei <fengwei.yin@intel.com>, io-uring <io-uring@vger.kernel.org>
Subject: Re: [PATCH] io_uring: ensure REQ_F_ISREG is set async offload
Date: Thu, 21 Jul 2022 19:36:02 -0600 [thread overview]
Message-ID: <389c6d6e-f524-35cb-14dd-9eb1d0c8f644@kernel.dk> (raw)
In-Reply-To: <3088d30d-567c-c64f-fe68-3585967afef4@intel.com>
On 7/21/22 5:43 PM, Yin Fengwei wrote:
>
> On 7/21/2022 11:11 PM, Jens Axboe wrote:
>> If we're offloading requests directly to io-wq because IOSQE_ASYNC was
>> set in the sqe, we can miss hashing writes appropriately because we
>> haven't set REQ_F_ISREG yet. This can cause a performance regression
>> with buffered writes, as io-wq then no longer correctly serializes writes
>> to that file.
>>
>> Ensure that we set the flags in io_prep_async_work(), which will cause
>> the io-wq work item to be hashed appropriately.
>>
>> Fixes: 584b0180f0f4 ("io_uring: move read/write file prep state into actual opcode handler")
>> Link: https://lore.kernel.org/io-uring/20220608080054.GB22428@xsang-OptiPlex-9020/
>> Reported-and-tested-by: Yin Fengwei <fengwei.yin@intel.com>
> This issue is reported by (from the original report):
>
> If you fix the issue, kindly add following tag
> Reported-by: kernel test robot <oliver.sang@intel.com>
Sorry, I missed that in the original. I'll be rebasing this branch this
weekend anyway, I'll try and remember to make the edit.
--
Jens Axboe
prev parent reply other threads:[~2022-07-22 1:36 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-07-21 15:11 [PATCH] io_uring: ensure REQ_F_ISREG is set async offload Jens Axboe
2022-07-21 23:43 ` Yin Fengwei
2022-07-22 1:36 ` Jens Axboe [this message]
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