[PATCH v2] memory-hotplug: remove redundant call of page_to_pfn

[PATCH v2] memory-hotplug: remove redundant call of page_to_pfn

[Zhang Zhen]

This is just a small optimization. The start_pfn can be
obtained directly by phys_index << PFN_SECTION_SHIFT.
So the call of page_to_pfn() is redundant and remove it.

v2:
	added the purpose of the patch to the description.

Signed-off-by: Zhang Zhen <zhenzhang.zhang@huawei.com>
Acked-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
---
 drivers/base/memory.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/base/memory.c b/drivers/base/memory.c
index 7c5d871..85be040 100644
--- a/drivers/base/memory.c
+++ b/drivers/base/memory.c
@@ -228,8 +228,8 @@ memory_block_action(unsigned long phys_index, unsigned long action, int online_t
 	struct page *first_page;
 	int ret;

-	first_page = pfn_to_page(phys_index << PFN_SECTION_SHIFT);
-	start_pfn = page_to_pfn(first_page);
+	start_pfn = phys_index << PFN_SECTION_SHIFT;
+	first_page = pfn_to_page(start_pfn);

 	switch (action) {
 		case MEM_ONLINE:
-- 
1.8.1.4


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