Re: [PATCH] Btrfs: throttle delayed refs better

[Johannes Hirte <johannes.hirte@datenkhaos.de>]

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.

regards,
  Johannes