Re: [RFC][PATCH 1/3] radix priority search tree - objrmap complexity fix

Andrea Arcangeli
2004-04-02T21:49:14Z

On Fri, Apr 02, 2004 at 11:45:48PM +0200, Pavel Machek wrote:
> Hi!
>
> > > > > An anonymous user page meets these requirements. A did say "anal", but
> > > > > rw_swap_page_sync() is a general-purpose library function and we shouldn't
> > > > > be making assumptions about the type of page which the caller happens to be
> > > > > feeding us.
> > > >
> > > > that is a specialized backdoor to do I/O on _private_ pages, it's not a
> > > > general-purpose library function for doing anonymous pages
> > > > swapin/swapout, infact the only user is swap susped and we'd better
> > > > forbid swap suspend to pass anonymous pages through that interface and
> > > > be sure that nobody will ever attempt anything like that.
> > > >
> > > > that interface is useful only to reach the swap device, for doing I/O on
> > > > private pages outside the VM, in the old days that was used to
> > > > read/write the swap header (again on a private page), swap suspend is
> > > > using it for similar reasons on _private_ pages.
> > >
> > > Ahha, so *here* is that discussion happening. I was only seeing it at
> > > bugzilla, and could not make sense of it.
> >
> > ;)
> >
> > btw, as far as I can tell I cannot see anymore VM issues with current CVS
> > kernel, what I get now is:
>
> What does "current CVS kernel" mean? Current one at bkcvs?

of course not, it means the kernel-source-26 that we used to reproduce
the suspend problem so far (mainline has no -mm writeback and no
anon-vma so it cannot have problems with rw_swap_page_sync).