Hi!
> > > > Ouch and IIRC top-level pagedir or something
> > > > like that lives in kernel "text" -- it is in assembly and
> > wrongly
> > > > placed.
> > > i386 does the right thing and put the pagedir in data segment.
> > x86_64
> > > not, I think we could clean it up.
> >
> > This probably should be done, first, and gotten past Andi.
> We asked the question to (intel's) BIOS guys, and below is the result.
> a. BIOS reserved region/hole - no save/restore
> b. ACPI NVS - save/restore
> c. 'ACPI Data' is a little tricky. After OS boots, os can reclaim this
> region, so regard it as normal ram. But we are afraid Linux runtime
> module loading might use this region somewhere, so we also mark this
> region as save/restore. Anyway, this hasn't any side effect.
> Hopefully all BIOSes follow this rule.
This comment needs to go somewhere in source.... aha, it is there,
mostly, but without the "tricky" remark.
> Pages (Reserved/ACPI NVS/ACPI Data) below
> end_pfn(x86_64)/max_low_pfn(i386) will be saved/restored by S4
> currently. We should mark 'Reserved' pages not saveable.
> Pages (Reserved/ACPI NVS/ACPI Data) above end_pfn/max_low_pfn
> will not be saved/restored by S4 currently. We should save the
> 'ACPI NVS/ACPI Data' pages in the highmem.
> Signed-off-by: Shaohua Li <shaohua.li@xxxxxxxxx>
> ---
>
> linux-2.6.17-rc1-root/arch/i386/kernel/setup.c | 101 +++++++++++++++++++++
> linux-2.6.17-rc1-root/arch/x86_64/kernel/setup.c | 93 +++++++++++++++++++
> linux-2.6.17-rc1-root/include/linux/suspend.h | 1
> linux-2.6.17-rc1-root/kernel/power/snapshot.c | 107 ++++++++++++++++++++++-
> linux-2.6.17-rc1-root/kernel/power/swsusp.c | 20 +---
> 5 files changed, 308 insertions(+), 14 deletions(-)
>
> diff -puN arch/i386/kernel/setup.c~nosave_pages arch/i386/kernel/setup.c
> --- linux-2.6.17-rc1/arch/i386/kernel/setup.c~nosave_pages 2006-04-04 15:10:42.000000000 +0800
> +++ linux-2.6.17-rc1-root/arch/i386/kernel/setup.c 2006-04-06 09:40:02.000000000 +0800
> @@ -1400,6 +1401,106 @@ static void set_mca_bus(int x)
> static void set_mca_bus(int x) { }
> #endif
>
> +#ifdef CONFIG_SOFTWARE_SUSPEND
> +static void __init mark_nosave_page_range(unsigned long start, unsigned long end)
> +{
> + struct page *page;
> + while (start <= end) {
> + page = pfn_to_page(start);
> + SetPageNosave(page);
> + start ++;
I think start++ is prefered style.
> diff -puN kernel/power/snapshot.c~nosave_pages kernel/power/snapshot.c
> --- linux-2.6.17-rc1/kernel/power/snapshot.c~nosave_pages 2006-04-04 15:10:42.000000000 +0800
> +++ linux-2.6.17-rc1-root/kernel/power/snapshot.c 2006-04-05 14:56:56.000000000 +0800
> @@ -39,6 +39,85 @@ static unsigned int nr_copy_pages;
> static unsigned int nr_meta_pages;
> static unsigned long *buffer;
>
> +struct arch_savable_page {
I believe we use "saveable" spelling. Either use it, too, or fix the
other occurences.
> + unsigned long start_pfn;
> + unsigned long end_pfn;
> + struct arch_savable_page *next;
> + void *data[0];
> +};
> +static struct arch_savable_page * arch_pages;
No space between * and arch_pages, please.
> +int swsusp_add_arch_pages(unsigned long start, unsigned long end)
> +{
> + struct arch_savable_page *tmp;
> + unsigned int size;
> +
> + end = end + 1;
> + size = sizeof(struct arch_savable_page) + sizeof(void *) * (end - start);
> + tmp = kzalloc(size, GFP_KERNEL);
That's potentialy quite a big allocation, no? Could we use highmem
(-like) per page saving?
Pavel
--
Thanks, Sharp!
