Re: sparsemem panic in 2.6.17-rc5-mm1 and -mm2

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Tue, 2006-06-06 at 21:58 -0700, Andrew Morton wrote:
> On Wed, 7 Jun 2006 09:43:55 +0900
> KAMEZAWA Hiroyuki <[email protected]> wrote:
> 
> > On Tue, 6 Jun 2006 00:27:58 -0700
> > Andrew Morton <[email protected]> wrote:
> > 
> > > 
> > > I tried sparsemem on my little x86 box here.  Boots OK, after fixing up the
> > > kswapd_init() patch (below).
> > > 
> > > I'm wondering why I have 4k of highmem:
> > > 
> > 
> > Could you show /proc/iomem of your 4k HIGHMEM box ?
> > Does 4k HIGHMEM exist only when SPARSEMEM is selected ?
> 
> Turns out that my 4 kbyte highmem zone (at least, as reported in
> /proc/meminfo) is due to
> 
> vdso-randomize-the-i386-vdso-by-moving-it-into-a-vma.patch

Thanks for this report, Andrew!

	Yes, MAXMEM is reduced by one page in the patch, taking into account
that kernel memory tops out at __FIXADDR_TOP, not 0xFFFFFFFF.  AFAICT
this is in fact a bugfix, which becomes more important when
__FIXADDR_TOP can be moved to create a larger memory hole (as for
hypervisors).

	You now have 1 page more memory available in your system.  Use it
wisely.

I'm sure Gerd will slap me if I'm wrong on this.  Here's the patch
fragment:

-#define MAXMEM                 (-__PAGE_OFFSET-__VMALLOC_RESERVE)
+#define MAXMEM                 (__FIXADDR_TOP-__PAGE_OFFSET-__VMALLOC_RESERVE)

Cheers,
Rusty.
-- 
 ccontrol: http://ccontrol.ozlabs.org

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

[Index of Archives]     [Kernel Newbies]     [Netfilter]     [Bugtraq]     [Photo]     [Stuff]     [Gimp]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Video 4 Linux]     [Linux for the blind]     [Linux Resources]
  Powered by Linux