* Yinghai Lu <yinghai@xxxxxxxxxx> wrote:
> please check
>
> [PATCH 01/20] x86: add find_e820_area_node
>
>
> [RFC PATCH] x86: use lmb to replace early_res
>
> still keep kernel/early_res.c for the extension.
>
> should move those file to lib/lmb.c later?
>
> Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx>
>
> ---
> arch/x86/Kconfig | 1
> arch/x86/include/asm/e820.h | 38 +-
> arch/x86/include/asm/lmb.h | 8
> arch/x86/kernel/e820.c | 163 +----------
> arch/x86/kernel/head.c | 2
> arch/x86/kernel/head32.c | 4
> arch/x86/kernel/head64.c | 2
> arch/x86/kernel/setup.c | 2
> arch/x86/kernel/setup_percpu.c | 6
> include/linux/early_res.h | 9
> include/linux/lmb.h | 5
> kernel/early_res.c | 594 ++++++++++++++++-------------------------
> lib/lmb.c | 9
> mm/page_alloc.c | 2
> mm/sparse-vmemmap.c | 4
> 15 files changed, 321 insertions(+), 528 deletions(-)
That looks like a very promising direction!
There's several things to do to make the approach fully clean:
1)
I think we want to shape this as a series of simpler (and bisectable) patches.
2)
I think we also need to concentrate the changes back into LMB:
> Index: linux-2.6/include/linux/early_res.h
> ===================================================================
> --- linux-2.6.orig/include/linux/early_res.h
> +++ linux-2.6/include/linux/early_res.h
> @@ -5,15 +5,18 @@
> extern void reserve_early(u64 start, u64 end, char *name);
> extern void reserve_early_overlap_ok(u64 start, u64 end, char *name);
> extern void free_early(u64 start, u64 end);
> -void free_early_partial(u64 start, u64 end);
> extern void early_res_to_bootmem(u64 start, u64 end);
>
> -void reserve_early_without_check(u64 start, u64 end, char *name);
> u64 find_early_area(u64 ei_start, u64 ei_last, u64 start, u64 end,
> u64 size, u64 align);
> u64 find_early_area_size(u64 ei_start, u64 ei_last, u64 start,
> u64 *sizep, u64 align);
> -u64 find_fw_memmap_area(u64 start, u64 end, u64 size, u64 align);
> +u64 find_lmb_area(u64 start, u64 end, u64 size, u64 align);
> +u64 find_lmb_area_size(u64 start, u64 *sizep, u64 align);
> +u64 find_lmb_area_node(int nid, u64 start, u64 end, u64 size, u64 align);
> +void lmb_register_active_regions(int nid, unsigned long start_pfn,
> + unsigned long last_pfn);
> +u64 lmb_hole_size(u64 start, u64 end);
> u64 get_max_mapped(void);
> #include <linux/range.h>
> int get_free_all_memory_range(struct range **rangep, int nodeid);
those new lmb_*() APIs should go into lmb.h.
3)
Furthermore, i think all of early_res.c should move into lmb.c as well and we
should eliminate kernel/early_res.c.
early_res.h will go away as well and all the new APIs will be in lmb.h.
4)
Also, we should move lib/lmb.c to mm/lmb.c, as now it's not just some optional
library but _the_ main early-reserve memory subsystem used by the biggest
Linux architectures.
5)
Could we perhaps also try to eliminate e820_*() method uses in arch/x86/, and
replace them by lmb_*() API uses? (that too should be a step by step method,
for bisectability)
> +++ linux-2.6/include/linux/lmb.h
> @@ -26,7 +26,8 @@ struct lmb_property {
> struct lmb_region {
> unsigned long cnt;
> u64 size;
> - struct lmb_property region[MAX_LMB_REGIONS+1];
> + struct lmb_property *region;
> + unsigned long region_array_size;
> };
I suspect this should keep current LMB architectures still working, right?
Ingo
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