Re: userspace pagecache management tool

Pádraig Brady
2007-03-07T11:41:59Z

Andrew Morton wrote:
> On Tue, 06 Mar 2007 12:10:49 +0000
> P__draig Brady <P@draigBrady.com> wrote:
>> Perhaps one could possibly just evict pages with _mapcount==0 ?
>
> That is the present fadvise(FADV_DONTNEED) behaviour.

Ah right. It doesn't invalidate page_mapped() pages.
If that means it doesn't invalidate pages previously cached
by other processes, then great.

However I think what I meant though was fadvise(FADV_DONTNEED)
should only invalidate pages where page_count()<=1

>From include/linux/mm.h

" For pages belonging to inodes, the page_count() is the number of
attaches, plus 1 if `private' contains something, plus one for
the page cache itself."

cheers,
Pádraig.