On Tuesday 30 June 2009, Wu Zhangjin wrote:
> From: Wu Zhangjin <wuzj@xxxxxxxxxx>
>
> when using hibernation(STD) with CONFIG_FLATMEM in linux-mips-64bit, it
> fails for the current mips-specific hibernation implementation save the
> pages in all of the memory space(except the nosave section) and make
> there will be not enough memory left to the STD task itself, and then
> fail. in reality, we only need to save the pages in system rams.
>
> here is the reason why it fail:
>
> kernel/power/snapshot.c:
>
> static void mark_nosave_pages(struct memory_bitmap *bm)
> {
> ...
> if (pfn_valid(pfn)) {
> ...
> }
> }
>
> arch/mips/include/asm/page.h:
>
> ...
> #ifdef CONFIG_FLATMEM
>
> #define pfn_valid(pfn) ((pfn) >= ARCH_PFN_OFFSET && (pfn) < max_mapnr)
>
> #elif defined(CONFIG_SPARSEMEM)
>
> /* pfn_valid is defined in linux/mmzone.h */
> ...
>
> we can rewrite pfn_valid(pfn) to fix this problem, but I really do not
> want to touch such a widely-used macro, so, I used another solution:
>
> static struct page *saveable_page(struct zone *zone, unsigned long pfn)
> {
> ...
> if ( .... pfn_is_nosave(pfn)
> return NULL;
> ...
> }
>
> and pfn_is_nosave is implemented in arch/mips/power/cpu.c, so, hacking
> this one is better.
Not really.
Could that be handled with the help of register_nosave_region() or
register_nosave_region_late() instead?
Best,
Rafael
> Signed-off-by: Wu Zhangjin <wuzj@xxxxxxxxxx>
> ---
> arch/mips/power/cpu.c | 19 ++++++++++++++++++-
> 1 files changed, 18 insertions(+), 1 deletions(-)
>
> diff --git a/arch/mips/power/cpu.c b/arch/mips/power/cpu.c
> index 7995df4..ef472e3 100644
> --- a/arch/mips/power/cpu.c
> +++ b/arch/mips/power/cpu.c
> @@ -10,6 +10,7 @@
> #include <asm/suspend.h>
> #include <asm/fpu.h>
> #include <asm/dsp.h>
> +#include <asm/bootinfo.h>
>
> static u32 saved_status;
> struct pt_regs saved_regs;
> @@ -34,10 +35,26 @@ void restore_processor_state(void)
> restore_dsp(current);
> }
>
> +int pfn_in_system_ram(unsigned long pfn)
> +{
> + int i;
> +
> + for (i = 0; i < boot_mem_map.nr_map; i++) {
> + if (boot_mem_map.map[i].type == BOOT_MEM_RAM) {
> + if ((pfn >= (boot_mem_map.map[i].addr >> PAGE_SHIFT)) &&
> + ((pfn) < ((boot_mem_map.map[i].addr +
> + boot_mem_map.map[i].size) >> PAGE_SHIFT)))
> + return 1;
> + }
> + }
> + return 0;
> +}
> +
> int pfn_is_nosave(unsigned long pfn)
> {
> unsigned long nosave_begin_pfn = PFN_DOWN(__pa(&__nosave_begin));
> unsigned long nosave_end_pfn = PFN_UP(__pa(&__nosave_end));
>
> - return (pfn >= nosave_begin_pfn) && (pfn < nosave_end_pfn);
> + return ((pfn >= nosave_begin_pfn) && (pfn < nosave_end_pfn))
> + || !pfn_in_system_ram(pfn);
> }
