Messages in this thread | | | Date | Thu, 22 Sep 2011 07:33:17 -0700 | Subject | Re: S4 resume broken since 2.6.39 (3.1, too) | From | Yinghai Lu <> |
| |
On Wed, Sep 21, 2011 at 11:48 AM, Rafael J. Wysocki <rjw@sisk.pl> wrote: > It looks like init_memory_mapping() is sometimes called with "end" > beyond the last mapped PFN and it explodes when we try to write stuff to > that address during image restoration. > > IOW, the Yinghai's assumption that init_memory_mapping() would always be > called with a "good end" on x86_64 was overomptimistic.
for 64bit x86, kernel_physical_mapping_init() will use map_low_page()/call early_memmap() to access ram for page_table that is above rather last mapped PFN.
the point is: on system with 64g, usable ram will be [0,2048m), [4g, 64g) init_memory_mapping will be called two times for them. before putting page_table high, page table will be two parts: one is just below 512M, and one below 2048m. after putting page_table high, page table will be two parts: one is just below 2048M, and one below 64G.
one of the purposes is finding biggest continuous big range under 1024m for kdump.
Thanks
Yinghai
| |