lkml.org 
[lkml]   [2004]   [Jan]   [14]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [RFC] /dev/anon
On Wed, 14 Jan 2004, Jeff Dike wrote:

> > I thought your goal was to release memory
> > to the host, that's why I proposed sys_madvise(MADV_DONTNEED).
>
> It is, I want memory released immediately as though it were clean, and
> MADV_DONTNEED doesn't help.

Strange, I didn't notice this before. If you look at the comment in
mm/madvise.c:madvise_dontneed, it advertises that dirty pages are actually
thrown away (that would be what you're actually looking for). But if you
go down to zap_page_range -> unmap_vmas -> unmap_page_range ->
zap_pmd_range -> zap_pte_range, if the page is dirty, set_page_dirty ->
__set_page_dirty_buffers pushes the page into the mapping dirty pages list
and __mark_inode_dirty push the inode inside the superblock dirty list. So
the comment seems to be wrong (I also verified this with a simple program,
and pages are actually flushed).



- Davide






-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-03-22 14:00    [W:0.081 / U:0.024 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site