diff options
| -rw-r--r-- | arch/x86/mm/init_64.c | 67 |
1 files changed, 61 insertions, 6 deletions
diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c index fa7948042bff..58ae2f746b3e 100644 --- a/arch/x86/mm/init_64.c +++ b/arch/x86/mm/init_64.c @@ -829,17 +829,42 @@ void __init paging_init(void) #ifdef CONFIG_SPARSEMEM_VMEMMAP #define PAGE_UNUSED 0xFD +/* + * The unused vmemmap range, which was not yet memset(PAGE_UNUSED), ranges + * from unused_pmd_start to next PMD_SIZE boundary. + */ +static unsigned long unused_pmd_start __meminitdata; + +static void __meminit vmemmap_flush_unused_pmd(void) +{ + if (!unused_pmd_start) + return; + /* + * Clears (unused_pmd_start, PMD_END] + */ + memset((void *)unused_pmd_start, PAGE_UNUSED, + ALIGN(unused_pmd_start, PMD_SIZE) - unused_pmd_start); + unused_pmd_start = 0; +} + +#ifdef CONFIG_MEMORY_HOTPLUG /* Returns true if the PMD is completely unused and thus it can be freed */ static bool __meminit vmemmap_pmd_is_unused(unsigned long addr, unsigned long end) { unsigned long start = ALIGN_DOWN(addr, PMD_SIZE); + /* + * Flush the unused range cache to ensure that memchr_inv() will work + * for the whole range. + */ + vmemmap_flush_unused_pmd(); memset((void *)addr, PAGE_UNUSED, end - addr); return !memchr_inv((void *)start, PAGE_UNUSED, PMD_SIZE); } +#endif -static void __meminit vmemmap_use_sub_pmd(unsigned long start) +static void __meminit __vmemmap_use_sub_pmd(unsigned long start) { /* * As we expect to add in the same granularity as we remove, it's @@ -851,23 +876,53 @@ static void __meminit vmemmap_use_sub_pmd(unsigned long start) memset((void *)start, 0, sizeof(struct page)); } +static void __meminit vmemmap_use_sub_pmd(unsigned long start, unsigned long end) +{ + /* + * We only optimize if the new used range directly follows the + * previously unused range (esp., when populating consecutive sections). + */ + if (unused_pmd_start == start) { + if (likely(IS_ALIGNED(end, PMD_SIZE))) + unused_pmd_start = 0; + else + unused_pmd_start = end; + return; + } + + /* + * If the range does not contiguously follows previous one, make sure + * to mark the unused range of the previous one so it can be removed. + */ + vmemmap_flush_unused_pmd(); + __vmemmap_use_sub_pmd(start); +} + + static void __meminit vmemmap_use_new_sub_pmd(unsigned long start, unsigned long end) { + vmemmap_flush_unused_pmd(); + /* * Could be our memmap page is filled with PAGE_UNUSED already from a * previous remove. Make sure to reset it. */ - vmemmap_use_sub_pmd(start); + __vmemmap_use_sub_pmd(start); /* * Mark with PAGE_UNUSED the unused parts of the new memmap range */ if (!IS_ALIGNED(start, PMD_SIZE)) memset((void *)start, PAGE_UNUSED, - start - ALIGN_DOWN(start, PMD_SIZE)); + start - ALIGN_DOWN(start, PMD_SIZE)); + + /* + * We want to avoid memset(PAGE_UNUSED) when populating the vmemmap of + * consecutive sections. Remember for the last added PMD where the + * unused range begins. + */ if (!IS_ALIGNED(end, PMD_SIZE)) - memset((void *)end, PAGE_UNUSED, - ALIGN(end, PMD_SIZE) - end); + unused_pmd_start = end; } #endif @@ -1538,7 +1593,7 @@ static int __meminit vmemmap_populate_hugepages(unsigned long start, return -ENOMEM; /* no fallback */ } else if (pmd_large(*pmd)) { vmemmap_verify((pte_t *)pmd, node, addr, next); - vmemmap_use_sub_pmd(addr); + vmemmap_use_sub_pmd(addr, next); continue; } if (vmemmap_populate_basepages(addr, next, node, NULL)) |