Messages in this thread | | | Date | Tue, 10 Nov 2009 13:00:53 +0100 | From | Johannes Weiner <> | Subject | Re: [PATCH -v2 6/9] bootmem: add free_bootmem_late |
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On Tue, Nov 10, 2009 at 07:46:17PM +0900, FUJITA Tomonori wrote: > Add a new function for freeing bootmem after the bootmem allocator has > been released and the unreserved pages given to the page allocator. > This allows us to reserve bootmem and then release it if we later > discover it was not needed. > > Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> > Cc: hannes@cmpxchg.org > Cc: akpm@linux-foundation.org > Cc: tj@kernel.org > Acked-by: Pekka Enberg <penberg@cs.helsinki.fi> > --- > include/linux/bootmem.h | 1 + > mm/bootmem.c | 24 ++++++++++++++++++++++++ > 2 files changed, 25 insertions(+), 0 deletions(-) > > diff --git a/include/linux/bootmem.h b/include/linux/bootmem.h > index dd97fb8..b10ec49 100644 > --- a/include/linux/bootmem.h > +++ b/include/linux/bootmem.h > @@ -53,6 +53,7 @@ extern void free_bootmem_node(pg_data_t *pgdat, > unsigned long addr, > unsigned long size); > extern void free_bootmem(unsigned long addr, unsigned long size); > +extern void free_bootmem_late(unsigned long addr, unsigned long size); > > /* > * Flags for reserve_bootmem (also if CONFIG_HAVE_ARCH_BOOTMEM_NODE, > diff --git a/mm/bootmem.c b/mm/bootmem.c > index ca92991..30f1702 100644 > --- a/mm/bootmem.c > +++ b/mm/bootmem.c > @@ -143,6 +143,30 @@ unsigned long __init init_bootmem(unsigned long start, unsigned long pages) > return init_bootmem_core(NODE_DATA(0)->bdata, start, 0, pages); > } > > +/* > + * free_bootmem_late - free bootmem pages directly to page allocator > + * @addr: starting address of the range > + * @size: size of the range in bytes > + * > + * This is only useful when the bootmem allocator has already been torn > + * down, but we are still initializing the system. Pages are given directly > + * to the page allocator, no bootmem metadata is updated because it is gone. > + */ > +void __init free_bootmem_late(unsigned long addr, unsigned long size) > +{ > + unsigned long cursor, end; > + > + kmemleak_free_part(__va(addr), size); > + > + cursor = PFN_UP(addr); > + end = PFN_DOWN(addr + size); > + > + for (; cursor < end; cursor++) { > + __free_pages_bootmem(pfn_to_page(cursor), 0); > + totalram_pages++; > + } > +}
I find it a bit weird that free_all_bootmem() callers have to take care of totalram_pages while this function does the accounting on its own.
And I think the function is more logically placed right below free_bootmem(), like you did in the header.
These are no show-stoppers for me, though, and otherwise the patch looks simple and straight-forward. Feel free to add
Reviewed-by: Johannes Weiner <hannes@cmpxchg.org>
Thanks!
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