Re: [PATCH]vmscan: handle underflow for get_scan_ratio

Shaohua Li
2010-03-30T08:13:45Z

On Tue, Mar 30, 2010 at 03:31:40PM +0800, KOSAKI Motohiro wrote:
> > > > > Very unfortunately, this patch isn't acceptable. In past time, vmscan
> > > > > had similar logic, but 1% swap-out made lots bug reports.
> > > > can you elaborate this?
> > > > Completely restore previous behavior (do full scan with priority 0) is
> > > > ok too.
> > >
> > > This is a option. but we need to know the root cause anyway.
> > I thought I mentioned the root cause in first mail. My debug shows
> > recent_rotated[0] is big, but recent_rotated[1] is almost zero, which makes
> > percent[0] 0. But you can double check too.
>
> To revert can save percent[0]==0 && priority==0 case. but it shouldn't
> happen, I think. It mean to happen big latency issue.
>
> Can you please try following patch? Also, I'll prepare reproduce environment soon.
still oom with the patch.