Re: [PATCH] Btrfs: throttle delayed refs better

[Josef Bacik <jbacik@fb.com>]

On 02/05/2014 12:34 PM, Johannes Hirte wrote:
> On Wed, 5 Feb 2014 10:49:15 -0500
> Josef Bacik <jbacik@fb.com> wrote:
>
>> Ok none of those make sense which makes me think it may be the ktime
>> bits, instead of un-applying the whole patch could you just comment
>> out the parts
>>
>>           ktime_t start = ktime_get();
>>
>> and
>>
>>           if (actual_count > 0) {
>>                   u64 runtime = ktime_to_ns(ktime_sub(ktime_get(),
>> start)); u64 avg;
>>
>>                   /*
>>                    * We weigh the current average higher than our
>> current runtime
>>                    * to avoid large swings in the average.
>>                    */
>>                   spin_lock(&delayed_refs->lock);
>>                   avg = fs_info->avg_delayed_ref_runtime * 3 + runtime;
>>                   avg = div64_u64(avg, 4);
>>                   fs_info->avg_delayed_ref_runtime = avg;
>>                   spin_unlock(&delayed_refs->lock);
>>           }
>>
>> in __btrfs_run_delayed_refs and see if that makes the problem stop?
>> If it does will you try chris's for-linus branch to see if it still
>> reproduces there?  Maybe some patch changed ktime_get() in -rc1 that
>> is causing issues and we're just now exposing it.  Thanks,
> With the ktime bits disabled, I wasn't able to reproduce the
> problem anymore. With Chris' for-linus branch it took longer but still
> appeared.
>
Ok can you send your .config, maybe there's some weird time bug being 
exposed.  What kind of CPU do you have?  Thanks,

Josef