Re: [PATCH 04/10] mini-os: respect memory map when ballooning up

[Juergen Gross <jgross@xxxxxxxx>]

On 12.12.21 01:26, Samuel Thibault wrote:
> Juergen Gross, le lun. 06 déc. 2021 08:23:31 +0100, a ecrit:
> > @@ -81,8 +93,11 @@ int balloon_up(unsigned long n_pages)
> >       if ( n_pages > N_BALLOON_FRAMES )
> >           n_pages = N_BALLOON_FRAMES;
> >   
> > +    start_pfn = e820_get_maxpfn(nr_mem_pages + 1) - 1;
> > +    n_pages = e820_get_max_pages(start_pfn, n_pages);
> I'd say call it e820_get_max_contig_pages?
Fine with me.

> > +unsigned long e820_get_max_pages(unsigned long pfn, unsigned long pages)
> > +{
> > +    int i;
> > +    unsigned long end;
> > +
> > +    for ( i = 0; i < e820_entries; i++ )
> > +    {
> > +        if ( e820_map[i].type != E820_RAM ||
> > +             (e820_map[i].addr >> PAGE_SHIFT) > pfn )
> > +            continue;
> "> pfn" looks odd to me? If the start of the e820 entry is already
> beyond pfn, we'll never find any other entry. We however do want to skip
> entries that have addr+size that is below pfn.
Oh, you are right.


Juergen

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