Messages in this thread |  | | Date | Mon, 16 Jun 2008 23:09:02 +0900 | From | Yasunori Goto <> | Subject | Re: [Patch 005/005](memory hotplug) free memmaps allocated by bootmem |
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> > Index: current/mm/sparse.c > > =================================================================== > > --- current.orig/mm/sparse.c 2008-04-07 20:13:25.000000000 +0900 > > +++ current/mm/sparse.c 2008-04-07 20:27:20.000000000 +0900 > > @@ -8,6 +8,7 @@ > > #include <linux/module.h> > > #include <linux/spinlock.h> > > #include <linux/vmalloc.h> > > +#include "internal.h" > > #include <asm/dma.h> > > #include <asm/pgalloc.h> > > #include <asm/pgtable.h> > > @@ -360,6 +361,9 @@ > > { > > return; /* XXX: Not implemented yet */ > > } > > +static void free_map_bootmem(struct page *page, unsigned long nr_pages) > > +{ > > +} > > #else > > static struct page *__kmalloc_section_memmap(unsigned long nr_pages) > > { > > @@ -397,17 +401,47 @@ > > free_pages((unsigned long)memmap, > > get_order(sizeof(struct page) * nr_pages)); > > } > > + > > +static void free_map_bootmem(struct page *page, unsigned long nr_pages) > > +{ > > + unsigned long maps_section_nr, removing_section_nr, i; > > + int magic; > > + > > + for (i = 0; i < nr_pages; i++, page++) { > > + magic = atomic_read(&page->_mapcount); > > + > > + BUG_ON(magic == NODE_INFO); > > Are we sure the node area was big enough to never allocate usemap's into > it and change the magic to MIX? I saw you make the section information > page sized but not the others.
I don't think this is finish for removing whole of node. Just preparing. I would like to make section removing at first rather than node.
> > + > > + maps_section_nr = pfn_to_section_nr(page_to_pfn(page)); > > + removing_section_nr = page->private; > > + > > + /* > > + * When this function is called, the removing section is > > + * logical offlined state. This means all pages are isolated > > + * from page allocator. If removing section's memmap is placed > > + * on the same section, it must not be freed. > > + * If it is freed, page allocator may allocate it which will > > + * be removed physically soon. > > + */ > > + if (maps_section_nr != removing_section_nr) > > + put_page_bootmem(page); > > Would the section memmap have its own get_page_bootmem reference here? > Would that not protect it from release?
It's not protected.
> > Index: current/mm/page_alloc.c > > =================================================================== > > --- current.orig/mm/page_alloc.c 2008-04-07 20:12:55.000000000 +0900 > > +++ current/mm/page_alloc.c 2008-04-07 20:13:29.000000000 +0900 > > @@ -568,7 +568,7 @@ > > /* > > * permit the bootmem allocator to evade page validation on high-order frees > > */ > > -void __init __free_pages_bootmem(struct page *page, unsigned int order) > > +void __free_pages_bootmem(struct page *page, unsigned int order) > > not __meminit or something?
Ah, yes. I'll fix it.
Thanks for comments.
Bye.
-- Yasunori Goto
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