On Wed, 17 Apr 2013, Yasuaki Ishimatsu wrote: > > Why not simply do what generic sparsemem support does by testing > > PageSlab(virt_to_head_page(res)) and calling kfree() if true and freeing > > back to bootmem if false? This should be like a five line patch. > > Is your explanation about free_section_usemap()? > If so, I don't think we can release resource structure like > free_section_usemap().
Right, you can't release it like free_section_usemap(), but you're free to test for PageSlab(virt_to_head_page(res)) in kernel/resource.c. > In your explanation case, memmap can be released by put_page_bootmem() in > free_map_bootmem() since all pages of memmap is used only for memmap. > But if my understanding is correct, a page of released resource structure > contain other purpose objects allocated by bootmem. So we cannot > release resource structure like free_section_usemap(). > I'm thinking it would be much easier to just suppress the kfree() if !PageSlab. If you can free an entire page with free_bootmem_late(), that would be great, but I'm thinking that will take more work than it's worth. It seems fine to just do free_bootmem() and leave those pages as reserved. How much memory are we talking about? -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
