Re: ENOSPC returned during writepages

Mingming Cao
2008-08-20T22:03:30Z

在 2008-08-20三的 17:55 -0400，Theodore Tso写道：
> On Wed, Aug 20, 2008 at 01:56:48PM -0700, Mingming Cao wrote:
> > > BTW, I was looking at the percpu_counter interface, and I'm confused
> > > why we have percpu_counter_sum_and_set() and percpu_counter_sum(). If
> > > we're taking the fbc->lock to calculate the precise value of the
> > > counter, why not simply set fbc->count?
> >
> > I added the percpu_count_sum_and _set() interface, when addingdelalloc
> > block reservation. I agree it make sense to clean up current all the
> > user of percpu_counter_sum() and replace with
> > percpu_counter_sum_and_set(), just hasn't get chance to clean up yet.
>
> Why not make percpu_counter_sum() always do sum_and_set, and change
> the ext4 calls to use percpu_counter_sum()? In fact, I'm wondering

I will clean this up.
> why you didn't do that in the first place? Was that your trying to be
> as conservative as possible with respect to not changing things?

Yeah, I think I am being over cautious, try not to impact to other user
of percpu_counter_sum()... no more excuse:)

Mingming
>
> - Ted