Why the above Bob's patch not included in 2.6.19 ?
It is still needed to boot ia64 platform.
Mel Gorman wrote:
>>>As you say, it's not clear why the normal discontig kernel boots because
>>>the regions should have been skipped by add_active_range().
>>>
>>
>> I think that depends on the init value of memmap, if they are all zero,
>> free_pages_check will be happy and not report any thing. So I guess we may
>> see this bug in normal kernel with a warm reboot, or with a machine which
>> PROM does not clear memory to all zero.
>
> It could have been just luck. See more below
>
>>
>>>Try your patch and see does it work for kdump. It should work fine in the
>>>normal case because at very worst, slightly more memmap is allocated than
>>>is strictly required.
>>>
>>
>> It works for kdump.
>>
>
> Can you try out the patch below please as a possibly simplier alternative? It's
> a patch from Bob Picco that addresses a similar problem with initmem on a
> kernel booting as normal. The only difference between Bob's original patch
> and this one is the addition of the CONFIG_KEXEC stuff from your patch. It
> survived a simply boot test.
>
> Thanks
>
>>>>Begin Bob's patch
>
> While pursuing and unrelated issue with 64Mb granules I noticed a problem
> related to inconsistent use of add_active_range. There doesn't appear any
> reason to me why FLATMEM versus DISCONTIG_MEM should register memory
> to add_active_range with different code. So I've changed the code into
> a common implementation.
>
> The other subtle issue fixed by this patch was calling add_active_range
> in count_node_pages before granule aligning is performed. We were lucky with
> 16MB granules but not so with 64MB granules. count_node_pages has reserved
> regions filtered out and as a consequence linked kernel text and data
> aren't covered by calls to count_node_pages. So linked kernel regions
> wasn't reported to add_active_regions. This resulted in free_initmem causing
> numerous bad_page reports. This won't occur with this patch because now
> all known memory regions are reported by register_active_ranges.
>
> Acked-by: Mel Gorman <mel@xxxxxxxxx>
> Signed-off-by: Bob Picco <bob.picco@xxxxxx>
>
> arch/ia64/mm/contig.c | 3 +--
> arch/ia64/mm/discontig.c | 4 +++-
> arch/ia64/mm/init.c | 24 +++++++++++++++++-------
> include/asm-ia64/meminit.h | 3 ++-
> 4 files changed, 23 insertions(+), 11 deletions(-)
>
> diff -rup -X /usr/src/patchset-0.6/bin//dontdiff linux-2.6.19-rc5-clean/arch/ia64/mm/contig.c linux-2.6.19-rc5-register_all_memory/arch/ia64/mm/contig.c
> --- linux-2.6.19-rc5-clean/arch/ia64/mm/contig.c 2006-11-08 02:24:20.000000000 +0000
> +++ linux-2.6.19-rc5-register_all_memory/arch/ia64/mm/contig.c 2006-11-16 15:29:31.000000000 +0000
> @@ -226,7 +226,6 @@ void __init
> paging_init (void)
> {
> unsigned long max_dma;
> - unsigned long nid = 0;
> unsigned long max_zone_pfns[MAX_NR_ZONES];
>
> num_physpages = 0;
> @@ -238,7 +237,7 @@ paging_init (void)
> max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
>
> #ifdef CONFIG_VIRTUAL_MEM_MAP
> - efi_memmap_walk(register_active_ranges, &nid);
> + efi_memmap_walk(register_active_ranges, NULL);
> efi_memmap_walk(find_largest_hole, (u64 *)&max_gap);
> if (max_gap < LARGE_GAP) {
> vmem_map = (struct page *) 0;
> diff -rup -X /usr/src/patchset-0.6/bin//dontdiff linux-2.6.19-rc5-clean/arch/ia64/mm/discontig.c linux-2.6.19-rc5-register_all_memory/arch/ia64/mm/discontig.c
> --- linux-2.6.19-rc5-clean/arch/ia64/mm/discontig.c 2006-11-08 02:24:20.000000000 +0000
> +++ linux-2.6.19-rc5-register_all_memory/arch/ia64/mm/discontig.c 2006-11-16 15:29:31.000000000 +0000
> @@ -473,6 +473,9 @@ void __init find_memory(void)
> node_clear(node, memory_less_mask);
> mem_data[node].min_pfn = ~0UL;
> }
> +
> + efi_memmap_walk(register_active_ranges, NULL);
> +
> /*
> * Initialize the boot memory maps in reverse order since that's
> * what the bootmem allocator expects
> @@ -654,7 +657,6 @@ static __init int count_node_pages(unsig
> {
> unsigned long end = start + len;
>
> - add_active_range(node, start >> PAGE_SHIFT, end >> PAGE_SHIFT);
> mem_data[node].num_physpages += len >> PAGE_SHIFT;
> if (start <= __pa(MAX_DMA_ADDRESS))
> mem_data[node].num_dma_physpages +=
> diff -rup -X /usr/src/patchset-0.6/bin//dontdiff linux-2.6.19-rc5-clean/arch/ia64/mm/init.c linux-2.6.19-rc5-register_all_memory/arch/ia64/mm/init.c
> --- linux-2.6.19-rc5-clean/arch/ia64/mm/init.c 2006-11-08 02:24:20.000000000 +0000
> +++ linux-2.6.19-rc5-register_all_memory/arch/ia64/mm/init.c 2006-11-16 15:33:25.000000000 +0000
> @@ -594,18 +594,28 @@ find_largest_hole (u64 start, u64 end, v
> return 0;
> }
>
> +#endif /* CONFIG_VIRTUAL_MEM_MAP */
> +
> int __init
> -register_active_ranges(u64 start, u64 end, void *nid)
> +register_active_ranges(u64 start, u64 end, void *arg)
> {
> - BUG_ON(nid == NULL);
> - BUG_ON(*(unsigned long *)nid >= MAX_NUMNODES);
> + int nid = paddr_to_nid(__pa(start));
> +
> + if (nid < 0)
> + nid = 0;
>
> - add_active_range(*(unsigned long *)nid,
> - __pa(start) >> PAGE_SHIFT,
> - __pa(end) >> PAGE_SHIFT);
> +#ifdef CONFIG_KEXEC
> + if (start > crashk_res.start && start < crashk_res.end)
> + start = max(start, crashk_res.end);
> + if (end > crashk_res.start && end < crashk_res.end)
> + end = min(end, crashk_res.start);
> +#endif
> +
> + if (start < end)
> + add_active_range(nid, __pa(start) >> PAGE_SHIFT,
> + __pa(end) >> PAGE_SHIFT);
> return 0;
> }
> -#endif /* CONFIG_VIRTUAL_MEM_MAP */
>
> static int __init
> count_reserved_pages (u64 start, u64 end, void *arg)
> diff -rup -X /usr/src/patchset-0.6/bin//dontdiff linux-2.6.19-rc5-clean/include/asm-ia64/meminit.h linux-2.6.19-rc5-register_all_memory/include/asm-ia64/meminit.h
> --- linux-2.6.19-rc5-clean/include/asm-ia64/meminit.h 2006-11-08 02:24:20.000000000 +0000
> +++ linux-2.6.19-rc5-register_all_memory/include/asm-ia64/meminit.h 2006-11-16 15:29:31.000000000 +0000
> @@ -50,12 +50,13 @@ extern void efi_memmap_init(unsigned lon
>
> #define IGNORE_PFN0 1 /* XXX fix me: ignore pfn 0 until TLB miss handler is updated... */
>
> +extern int register_active_ranges (u64 start, u64 end, void *arg);
> +
> #ifdef CONFIG_VIRTUAL_MEM_MAP
> # define LARGE_GAP 0x40000000 /* Use virtual mem map if hole is > than this */
> extern unsigned long vmalloc_end;
> extern struct page *vmem_map;
> extern int find_largest_hole (u64 start, u64 end, void *arg);
> - extern int register_active_ranges (u64 start, u64 end, void *arg);
> extern int create_mem_map_page_table (u64 start, u64 end, void *arg);
> extern int vmemmap_find_next_valid_pfn(int, int);
> #else
>
--
+===========+=======================+==================================+
| |\/\/\/| | | |
| | | |Christian Cotte-Barrot |org. :BULL/ |
| | (~)(o) |Bull S.A. |office:FREC/B1-401 |
| C _) |1, rue de Provence |mailto: |
| | ,___| |B.P. 208 | Christian.Cotte-Barrot@xxxxxxxx|
| | / |38432 ECHIROLLES CEDEX |phone :+33 (0)476297725 (229 7725)|
| /----\ |FRANCE |fax :+33 (0)476297518 (229 7518)|
+===========+=======================+==================================+
-
To unsubscribe from this list: send the line "unsubscribe linux-ia64" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
|