Re: [PATCH] mm/filemap.c: unconditionally call mark_page_accessed

Andrea Arcangeli
2007-03-15T21:49:34Z

On Thu, Mar 15, 2007 at 11:07:35AM -0800, Andrew Morton wrote:
> > On Thu, 15 Mar 2007 01:22:45 -0400 (EDT) Ashif Harji <asharji@cs.uwaterloo.ca> wrote:
> > I still think the simple fix of removing the
> > condition is the best approach, but I'm certainly open to alternatives.
>
> Yes, the problem of falsely activating pages when the file is read in small
> hunks is worse than the problem which your patch fixes.

Really? I would have expected all performance sensitive apps to read
in >=PAGE_SIZE chunks. And if they don't because they split their
dataset in blocks (like some database), it may not be so wrong to
activate those pages that have two "hot" blocks more aggressively than
those pages with a single hot block.

So I've an hard time to advocate to prefer the current behavior, but
certainly this can be "fixed" by caching the last_offset like others
pointed out ;)