aboutsummaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
authorJianyu Zhan <nasa4836@gmail.com>2014-01-21 15:49:12 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2014-01-21 16:19:44 -0800
commitece86e222db48d04bda218a2be70e384518bb08c (patch)
tree7cc9c61ca2f0f7112c2ed3698133aa559b6604ef
parentd80be7c75136fb58ed7264ac8a49dd917ace77a1 (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>
-rw-r--r--mm/vmalloc.c20
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 ***/

Privacy Policy