Re: New data=ordered code pushed out to btrfs-unstable

Ric Wheeler
2008-07-21T19:23:33Z

Chris Mason wrote:
> On Mon, 2008-07-21 at 14:29 -0400, Ric Wheeler wrote:
>
>> Chris Mason wrote:
>>
>>> On Sun, 2008-07-20 at 09:46 -0400, Ric Wheeler wrote:
>>>
>>>
>>>>
>>>>
>>>>
>>>>>>>>>> Just to kick the tires, I tried the same test that I ran last week on
>>>>>>>>>> ext4. Everything was going great, I decided to kill it after 6 million
>>>>>>>>>> files or so and restart.
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>> Well, it looks like I neglected to push all the changesets, especially
>>>>>>> the last one that made it less racey. So, I've just done another push,
>>>>>>> sorry. For the fs_mark workload, it shouldn't change anything.
>>>>>>>
>>>>>>> This code still hasn't really survived an overnight run, hopefully this
>>>>>>> commit will.
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>> The test is still running, but slowly, with a (slow) stream of messages
>>>>>> about:
>>>>>>
>>>>>>
>>> [ lock timeouts and stalls ]
>>>
>>>
>>> Ok, I've made a few changes that should lower overall contenion on the
>>> allocation mutex. I'm getting better performance on a 3 million file
>>> run, please give it a shot.
>>>
>>> -chris
>>>
>>>
>>>
>> Hi Chris,
>>
>> After an update, clean rebuild & reboot, the test is running along and
>> has hit about 10 million files. I still see some messages like:
>>
>> INFO: task pdflush:4051 blocked for more than 120 seconds.
>> "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
>> pdflush D ffffffff8129c5b0 0 4051 2
>> ffff81002ae77870 0000000000000046 0000000000000000 ffff81002ae77834
>> 0000000000000001 ffffffff814b2280 ffffffff814b2280 0000000100000001
>> 0000000000000000 ffff81003f188000 ffff81003fac5980 ffff81003f188350
>>
>> but not as many as before.
>>
>> I will attach the messages file,
>>
>
> I'll try running with soft-lockup detection here, see if I can hunt down
> the cause of these stalls. Good to know I've made progress though ;)
>
> -chris
>
>
This is an 8 core box, so it is might be more prone to hitting these
things ;-)

ric