vm_page_startup()
Alan Cox
alc at rice.edu
Wed Dec 1 06:21:25 UTC 2010
Given this bit of code in the MIPS pmap:
vm_offset_t
pmap_map(vm_offset_t *virt, vm_offset_t start, vm_offset_t end, int prot)
{
vm_offset_t va, sva;
if (MIPS_DIRECT_MAPPABLE(end))
return (MIPS_PHYS_TO_DIRECT(start));
The following in vm_page_startup() can apply to MIPS (as well as amd64):
#ifdef __amd64__
/*
* pmap_map on amd64 comes out of the direct-map, not kvm like i386,
* so the pages must be tracked for a crashdump to include this data.
* This includes the vm_page_array and the early UMA bootstrap pages.
*/
for (pa = new_end; pa < phys_avail[biggestone + 1]; pa += PAGE_SIZE)
dump_add_page(pa);
#endif
Even if a particular MIPS-based machine didn't wind up using the direct
map for the pmap_map calls in vm_page_startup() there would be no harm
in having called dump_add_page(). On the other hand, if you don't call
dump_add_page() when the direct map is used, you're crash dump will be
missing some kernel data structures.
Regards,
Alan
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