diff options
| author | Jianyu Zhan <nasa4836@gmail.com> | 2014-01-21 15:49:12 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-01-21 16:19:44 -0800 |
| commit | ece86e222db48d04bda218a2be70e384518bb08c (patch) | |
| tree | 7cc9c61ca2f0f7112c2ed3698133aa559b6604ef /mm/vmalloc.c | |
| parent | d80be7c75136fb58ed7264ac8a49dd917ace77a1 (diff) | |
mm/vmalloc: interchage the implementation of vmalloc_to_{pfn,page}
Currently we are implementing vmalloc_to_pfn() as a wrapper around
vmalloc_to_page(), which is implemented as follow:
1. walks the page talbes to generates the corresponding pfn,
2. then converts the pfn to struct page,
3. returns it.
And vmalloc_to_pfn() re-wraps vmalloc_to_page() to get the pfn.
This seems too circuitous, so this patch reverses the way: implement
vmalloc_to_page() as a wrapper around vmalloc_to_pfn(). This makes
vmalloc_to_pfn() and vmalloc_to_page() slightly more efficient.
No functional change.
Signed-off-by: Jianyu Zhan <nasa4836@gmail.com>
Cc: Vladimir Murzin <murzin.v@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/vmalloc.c')
| -rw-r--r-- | mm/vmalloc.c | 20 |
1 files changed, 10 insertions, 10 deletions
diff --git a/mm/vmalloc.c b/mm/vmalloc.c index 0fdf96803c5b..e4f0db2a3eae 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -220,12 +220,12 @@ int is_vmalloc_or_module_addr(const void *x) } /* - * Walk a vmap address to the struct page it maps. + * Walk a vmap address to the physical pfn it maps to. */ -struct page *vmalloc_to_page(const void *vmalloc_addr) +unsigned long vmalloc_to_pfn(const void *vmalloc_addr) { unsigned long addr = (unsigned long) vmalloc_addr; - struct page *page = NULL; + unsigned long pfn = 0; pgd_t *pgd = pgd_offset_k(addr); /* @@ -244,23 +244,23 @@ struct page *vmalloc_to_page(const void *vmalloc_addr) ptep = pte_offset_map(pmd, addr); pte = *ptep; if (pte_present(pte)) - page = pte_page(pte); + pfn = pte_pfn(pte); pte_unmap(ptep); } } } - return page; + return pfn; } -EXPORT_SYMBOL(vmalloc_to_page); +EXPORT_SYMBOL(vmalloc_to_pfn); /* - * Map a vmalloc()-space virtual address to the physical page frame number. + * Map a vmalloc()-space virtual address to the struct page. */ -unsigned long vmalloc_to_pfn(const void *vmalloc_addr) +struct page *vmalloc_to_page(const void *vmalloc_addr) { - return page_to_pfn(vmalloc_to_page(vmalloc_addr)); + return pfn_to_page(vmalloc_to_pfn(vmalloc_addr)); } -EXPORT_SYMBOL(vmalloc_to_pfn); +EXPORT_SYMBOL(vmalloc_to_page); /*** Global kva allocator ***/ |