Robin Holt wrote: [Wed Apr 12 2006, 03:18:55AM EDT]
> On Thu, Mar 30, 2006 at 09:48:18AM -0800, Chen, Kenneth W wrote:
> > Jack Steiner wrote on Thursday, March 30, 2006 9:29 AM
> > > > Time is wasted trying to fill the TLB entry for the vmem_map. When it
> > > > fails, we show_mem() advances to the next page which repeats the sequence.
> > > > Jack had thrown out a couple suggestions. One was essentially what
> > > > you proposed below. The other was advance i to point the next page
> > > > of pfns. He frowned when saying the second, but I don't recall exactly
> > > > why he frowned.
> > >
> > > Advancing to the next page will be considerably faster but I wonder if
> > > it is fast enough.
> > >
> ...
> > > My gut feeling is that is not good enough.
> >
> > What about the earlier proposal of advancing at pmd and pud granule by
> > walking the page table? There it can walk at 32MB/64GB step.
>
> Does the attached seem like the right direction? I have tested it on
> the simulator and it seems _much_ faster, but that is the simulator.
> I have time reserved on the machine where the problem was first observed
> later today to test it on actual hardware.
>
> Thanks,
> Robin
>
>
> Index: linux-2.6/arch/ia64/mm/discontig.c
> ===================================================================
> --- linux-2.6.orig/arch/ia64/mm/discontig.c 2006-04-11 16:06:54.243967238 -0500
> +++ linux-2.6/arch/ia64/mm/discontig.c 2006-04-12 02:16:46.111406150 -0500
> @@ -567,8 +567,68 @@ void show_mem(void)
> struct page *page;
> if (pfn_valid(pgdat->node_start_pfn + i))
> page = pfn_to_page(pgdat->node_start_pfn + i);
> - else
> + else {
Looks great and will work for VIRTUAL_MEM_MAP. It's too bad SPARSEMEM
can't be used because this probably wouldn't be an issue.
I think this will break SPARSEMEM. Perhaps it's time to create a new
module with VIRTUAL_MEM_MAP specific code in it. Say like vmemmap.c.
Lots of code in init.c and this new code could reside in this new
module. Just a thought. You'll need a compile time optimized out feature for
SPARSEMEM but for VIRTUAL_MEM_MAP a function call could be called.
bob
[snip]
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