Re: [PATCH v3] mm: swap: properly update readahead statistics in unuse_pte_range()

[Andrew Morton]

On Fri, 17 Apr 2020 11:01:22 +0800 "Huang\, Ying" <ying.huang@xxxxxxxxx> wrote:

> Andrea Righi <andrea.righi@xxxxxxxxxxxxx> writes:
> 
> > In unuse_pte_range() we blindly swap-in pages without checking if the
> > swap entry is already present in the swap cache.
> >
> > By doing this, the hit/miss ratio used by the swap readahead heuristic
> > is not properly updated and this leads to non-optimal performance during
> > swapoff.
> 
> It's more important to describe why we need this patch in the patch
> description.  So, please add some information about your use case.  And
> please focus on the technical part instead of the business part.

Confused.  I thought the changelog was quite good.  If "business part"
means "end user effect of the patch" then that's a very important
thing.

> Thanks!  But you don't need to do this.  You can add my Reviewed-by after
> we have finished the work on patch description.

Can you be more specific about how you want this changed?