Messages in this thread Patch in this message | | | From | Wei Yang <> | Subject | [PATCH 4/6] x86, mm: make split_mem_range() more easy to read | Date | Tue, 12 Feb 2019 10:12:13 +0800 |
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As the comment explains, there are at most 5 possible ranges:
kkkmmmGGGmmmkkk (A)(B)(C)(D)(E)
While there are two ways to perceive:
* C & D are extra ranges on X86_64 * B & C are extra ranges on X86_64
Current implementation takes the first way, which leads to handling end_pfn of B differently:
* align to PMD on X86_32 * align to PUD on X86_64
If we take the second way, we don't need to handle it differently.
* the end_pfn of B only need to align to PUD * the end_pfn of D only need to align to PMD
This patch changes the implementation from the first perception to the second to reduce one different handling on end_pfn. After doing so, the code is easier to read.
Signed-off-by: Wei Yang <richardw.yang@linux.intel.com> --- arch/x86/mm/init.c | 8 ++------ 1 file changed, 2 insertions(+), 6 deletions(-)
diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c index 2b782dcd6d71..87275238dbb0 100644 --- a/arch/x86/mm/init.c +++ b/arch/x86/mm/init.c @@ -389,25 +389,21 @@ static int __meminit split_mem_range(struct map_range *mr, pfn = end_pfn; } +#ifdef CONFIG_X86_64 /* * Range (B): * big page (2M) range */ start_pfn = round_up(pfn, PFN_DOWN(PMD_SIZE)); -#ifdef CONFIG_X86_32 - end_pfn = round_down(limit_pfn, PFN_DOWN(PMD_SIZE)); -#else /* CONFIG_X86_64 */ end_pfn = round_up(pfn, PFN_DOWN(PUD_SIZE)); if (end_pfn > round_down(limit_pfn, PFN_DOWN(PMD_SIZE))) end_pfn = round_down(limit_pfn, PFN_DOWN(PMD_SIZE)); -#endif if (start_pfn < end_pfn) { nr_range = save_mr(mr, nr_range, start_pfn, end_pfn, page_size_mask & (1<<PG_LEVEL_2M)); pfn = end_pfn; } -#ifdef CONFIG_X86_64 /* * Range (C): * big page (1G) range @@ -420,6 +416,7 @@ static int __meminit split_mem_range(struct map_range *mr, ((1<<PG_LEVEL_2M)|(1<<PG_LEVEL_1G))); pfn = end_pfn; } +#endif /* * Range (D): @@ -432,7 +429,6 @@ static int __meminit split_mem_range(struct map_range *mr, page_size_mask & (1<<PG_LEVEL_2M)); pfn = end_pfn; } -#endif /* * Range (E): -- 2.19.1
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