linux-kernel - [PATCH 1/2] hv_balloon: simplify math in alloc_balloon

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Date:   Wed,  2 Dec 2020 17:12:44 +0100
From:   Vitaly Kuznetsov <vkuznets@...hat.com>
To:     linux-hyperv@...r.kernel.org
Cc:     Wei Liu <wei.liu@...nel.org>,
        Stephen Hemminger <sthemmin@...rosoft.com>,
        Haiyang Zhang <haiyangz@...rosoft.com>,
        Michael Kelley <mikelley@...rosoft.com>,
        Dexuan Cui <decui@...rosoft.com>,
        David Hildenbrand <david@...hat.com>,
        linux-kernel@...r.kernel.org, linux-mm@...ck.org
Subject: [PATCH 1/2] hv_balloon: simplify math in alloc_balloon_pages()

'alloc_unit' in alloc_balloon_pages() is either '512' for 2M allocations or
'1' for 4k allocations. So

1 << get_order(alloc_unit << PAGE_SHIFT)

equals to 'alloc_unit' and the for loop basically sets all them offline.
Simplify the math to improve the readability.

Signed-off-by: Vitaly Kuznetsov <vkuznets@...hat.com>
---
 drivers/hv/hv_balloon.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/hv/hv_balloon.c b/drivers/hv/hv_balloon.c
index eb56e09ae15f..da3b6bd2367c 100644
--- a/drivers/hv/hv_balloon.c
+++ b/drivers/hv/hv_balloon.c
@@ -1238,7 +1238,7 @@ static unsigned int alloc_balloon_pages(struct hv_dynmem_device *dm,
 			split_page(pg, get_order(alloc_unit << PAGE_SHIFT));
 
 		/* mark all pages offline */
-		for (j = 0; j < (1 << get_order(alloc_unit << PAGE_SHIFT)); j++)
+		for (j = 0; j < alloc_unit; j++)
 			__SetPageOffline(pg + j);
 
 		bl_resp->range_count++;
-- 
2.26.2