Re: [PATCH]vmscan: handle underflow for get_scan_ratio

Shaohua Li
2010-04-02T09:24:49Z

On Fri, Apr 02, 2010 at 05:14:38PM +0800, KOSAKI Motohiro wrote:
> > > > This patch makes a lot of sense than previous. however I think <1% anon ratio
> > > > shouldn't happen anyway because file lru doesn't have reclaimable pages.
> > > > <1% seems no good reclaim rate.
> > >
> > > Oops, the above mention is wrong. sorry. only 1 page is still too big.
> > > because under streaming io workload, the number of scanning anon pages should
> > > be zero. this is very strong requirement. if not, backup operation will makes
> > > a lot of swapping out.
> > Sounds there is no big impact for the workload which you mentioned with the patch.
> > please see below descriptions.
> > I updated the description of the patch as fengguang suggested.
>
> Umm.. sorry, no.
>
> "one fix but introduce another one bug" is not good deal. instead,
> I'll revert the guilty commit at first as akpm mentioned.
Even we revert the commit, the patch still has its benefit, as it increases
calculation precision, right?

Thanks,
Shaohua