svn commit: r258039 - in head/sys: kern vm

[John-Mark Gurney]

Bruce Evans wrote this message on Tue, Nov 12, 2013 at 22:13 +1100:
> On Tue, 12 Nov 2013, Konstantin Belousov wrote:
> 
> >Log:
> > Avoid overflow for the page counts.
> >
> > Reported and tested by:	pho
> > Sponsored by:	The FreeBSD Foundation
> > MFC after:	1 week
> 
> >Modified: head/sys/kern/vfs_vnops.c
> >==============================================================================
> >--- head/sys/kern/vfs_vnops.c	Tue Nov 12 08:32:10 2013	(r258038)
> >+++ head/sys/kern/vfs_vnops.c	Tue Nov 12 08:47:58 2013	(r258039)
> >@@ -933,8 +933,9 @@ vn_io_fault(struct file *fp, struct uio
> >	void *rl_cookie;
> >	struct mount *mp;
> >	vm_page_t *prev_td_ma;
> >-	int cnt, error, save, saveheld, prev_td_ma_cnt;
> >+	int error, save, saveheld, prev_td_ma_cnt;
> >	vm_offset_t addr, end;
> >+	vm_size_t cnt;
> 
> int was correct for a count.  You can't possibly have the 8TB
> of physical memory needed to overflow a 32-bit int page count.
                    ^ today
> It is reasonably to assume 32-bit ints.

Except that the modern AMD64 arch now allows 52 bits of address for
phyiscal memory, which does mean in a few years, we will be eclipsing
8TB in a single machine...

Isn't someone running FreeBSD on a 1TB machine?  I'm pretty possitive
I remeber someone running 512GB, so only 3/4 doublings away from hitting
the limit...

-- 
  John-Mark Gurney				Voice: +1 415 225 5579

     "All that I will do, has been done, All that I have, has not."