Re: [LKP] [btrfs] 302167c50b: fio.write_bw_MBps -12.4% regression

From: Huang\, Ying
Date: Wed May 08 2019 - 03:58:00 EST


"Huang, Ying" <ying.huang@xxxxxxxxx> writes:

> Hi, Josef,
>
> kernel test robot <rong.a.chen@xxxxxxxxx> writes:
>
>> Greeting,
>>
>> FYI, we noticed a -12.4% regression of fio.write_bw_MBps due to commit:
>>
>>
>> commit: 302167c50b32e7fccc98994a91d40ddbbab04e52 ("btrfs: don't end the transaction for delayed refs in throttle")
>> https://git.kernel.org/cgit/linux/kernel/git/next/linux-next.git pending-fixes
>>
>> in testcase: fio-basic
>> on test machine: 88 threads Intel(R) Xeon(R) CPU E5-2699 v4 @ 2.20GHz with 64G memory
>> with following parameters:
>>
>> runtime: 300s
>> nr_task: 8t
>> disk: 1SSD
>> fs: btrfs
>> rw: randwrite
>> bs: 4k
>> ioengine: sync
>> test_size: 400g
>> cpufreq_governor: performance
>> ucode: 0xb00002e
>>
>> test-description: Fio is a tool that will spawn a number of threads or processes doing a particular type of I/O action as specified by the user.
>> test-url: https://github.com/axboe/fio
>>
>>
>
> Do you have time to take a look at this regression?

Ping

Best Regards,
Huang, Ying