Re: [PATCH] lazy freeing of memory through MADV_FREE 2/2

Andrew Morton
2007-04-20T21:03:39Z

On Thu, 19 Apr 2007 17:15:28 -0400
Rik van Riel <riel@redhat.com> wrote:

> Restore MADV_DONTNEED to its original Linux behaviour. This is still
> not the same behaviour as POSIX, but applications may be depending on
> the Linux behaviour already. Besides, glibc catches POSIX_MADV_DONTNEED
> and makes sure nothing is done...

OK, we need to flesh this out a lot please. People often get confused
about what our MADV_DONTNEED behaviour is. I regularly forget, then look
at the code, then get it wrong. That's for mainline, let alone older
kernels whose behaviour is gawd-knows-what.

So... For the changelog (and the manpage) could we please have a full
description of the 2.6.21 behaviour and the 2.6.21-post-rik behaviour (and
the 2.4 behaviour, if it differs at all)? Also some code comments to
demystify all of this once and for all?

Thanks.