Hi,
On Monday, 23 October 2006 16:50, Pavel Machek wrote:
> Hi!
>
> > The purpose of the appended patch is to make swsusp work on i386 with PAE,
> > but it should also allow i386 systems without PSE to use swsusp.
> >
> > The patch creates temporary page tables located in resume-safe page frames
> > during the resume and uses them for restoring the suspend image (the same
> > approach is used on x86-64).
> >
> > It has been tested on an i386 system with PAE and survived several
> > suspend-resume cycles in a row, but I have no systems without PSE, so that
> > requires some testing.
>
> Thanks, looks okay to me. I guess Andi Kleen would be right person to
> review it in detail?
Yes, I think so.
> Lack of assembly modifications is good.
>
> I guess this should be now removed? (include/asm-i386/suspend.h)
>
> arch_prepare_suspend(void)
> {
> /* If you want to make non-PSE machine work, turn off paging
> in swsusp_arch_suspend. swsusp_pg_dir should have identity mapping, so
> it could work... */
> if (!cpu_has_pse) {
> printk(KERN_ERR "PSE is required for swsusp.\n");
> return -EPERM;
> }
Yes, it should. I though it went away when the Kconfig was changed ...
> > +/*
> > + * Create a middle page table on a resume-safe page and put a pointer to it in
> > + * the given global directory entry. This only returns the gd entry
> > + * in non-PAE compilation mode, since the middle layer is folded.
> > + */
> > +static pmd_t *resume_one_md_table_init(pgd_t *pgd)
> > +{
> > + pud_t *pud;
> > + pmd_t *pmd_table;
> > +
> > +#ifdef CONFIG_X86_PAE
> > + pmd_table = (pmd_t *)get_safe_page(GFP_ATOMIC);
> > + if (!pmd_table)
> > + return pmd_table;
>
> I'd do plain old return NULL; here.
OK
> > + /* Map with big pages if possible, otherwise create
> > + * normal page tables.
> > + * NOTE: We can mark everything as executable here
> > + */
> > + if (cpu_has_pse) {
> > + set_pmd(pmd, pfn_pmd(pfn, PAGE_KERNEL_LARGE_EXEC));
> > + pfn += PTRS_PER_PTE;
>
> Perhaps disabling PSE here can help getting some testing?
Well, I don't really want to make everyone test the !PSE scenario. ;-)
> Okay, I guess I should really test this one... Seems good enough for
> -mm to me, but it should preferably stay there for a _long_ time.
I think so too.
Greetings,
Rafael
--
You never change things by fighting the existing reality.
R. Buckminster Fuller
