Broadcomm BCM4401-B0 and memory upgrade issue.

Steve Kargl sgk at
Tue Jan 24 13:24:00 PST 2006

On Tue, Jan 24, 2006 at 03:12:17PM -0600, Mark Tinguely wrote:
> Have you tried to boot with the old contigmalloc using the sysctl
> option "vm.old_contigmalloc=1"?

Yes.  This makes an enormous difference in boot up times.
With vm.old_contigmalloc=1, fxp0 probes within a few seconds.
Without it, fxp0 takes more than 7 minutes to probe.

> Some people are seeing slow boot/configuration with new style
> vm_page_alloc_contig/contigmalloc.


> I am doing some profiling of vm_page_alloc_contig() and have found
> that larger physical memory configurations makes these problems much worse.

yep.  I have 12 GB.

> I identified 4-5 places that can be changed to decrease the number
> of page tables that is needed to be checked before an allocating a range.
> Some of the changes will only occasionally save a few page checks, but
> others changes could save several hundred or more page checks on every call.

If you come up with a patch, I'm more than willing to test it.


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