Re: [PATCH 2.6.14-rc2] fix incorrect mm->hiwater_vm and mm->hiwater_rss

[Hugh Dickins <hugh@veritas.com>]

On Thu, 6 Oct 2005, Jay Lan wrote:
> Jay Lan wrote:
> > Hugh Dickins wrote:
> > > 
> > > See comment in fs/proc/task_mmu.c for the principle.  Could maintain
> > > hiwater_vm straightforwardly, but I think it's easier to remember if
> > > we handle them both in the same way.
> > 
> > I am building a kernel with your patch and am going to run some test
> > to compare the statistics.
> 
> My testing showed the same number on hiwater_vm, but hiwater_rss from
> Hugh's version was consistently ~1.5% lower. Where was the loss?

Thanks for trying it out.  Please check if you adjusted the way in which
you collect hiwater_rss: as in the example in task_mmu.c, it's no longer
any good just reading hiwater_rss, you need the max of get_mm_rss and
hiwater_rss each time.  Similarly for hiwater_vm.

Hugh