[lkml]   [2009]   [Feb]   [24]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: [PATCH 20/20] Get rid of the concept of hot/cold page freeing
On Tue, 24 Feb 2009 11:51:26 +0000
Mel Gorman <> wrote:

> > > Almost the opposite with steady improvements almost all the way through.
> > >
> > > With the patch applied, we are still using hot/cold information on the
> > > allocation side so I'm somewhat surprised the patch even makes much of a
> > > difference. I'd have expected the pages being freed to be mostly hot.
> >
> > Oh yeah. Back in the ancient days, hot-cold-pages was using separate
> > magazines for hot and cold pages. Then Christoph went and mucked with
> > it, using a single queue. That might have affected things.
> >
> It might have. The impact is that requests for cold pages can get hot pages
> if there are not enough cold pages in the queue so readahead could prevent
> an active process getting cache hot pages. I don't think that would have
> showed up in the microbenchmark though.

We switched to doing non-temporal stores in copy_from_user(), didn't
we? That would rub out the benefit which that microbenchmark

 \ /
  Last update: 2009-02-25 01:05    [W:0.087 / U:9.912 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site