linux-kernel - [PATCH] mm/vmalloc: terminate searching since one node found

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Date:   Sun, 16 Jul 2017 15:23:47 +0800
From:   Zhaoyang Huang <huangzhaoyang@...il.com>
To:     zhaoyang.huang@...eadtrum.com,
        Andrew Morton <akpm@...ux-foundation.org>,
        Michal Hocko <mhocko@...e.com>, Ingo Molnar <mingo@...nel.org>,
        zijun_hu <zijun_hu@....com>, Vlastimil Babka <vbabka@...e.cz>,
        Thomas Garnier <thgarnie@...gle.com>,
        "Kirill A. Shutemov" <kirill.shutemov@...ux.intel.com>,
        Andrey Ryabinin <aryabinin@...tuozzo.com>, linux-mm@...ck.org,
        linux-kernel@...r.kernel.org
Subject: [PATCH] mm/vmalloc: terminate searching since one node found

From: Zhaoyang Huang <zhaoyang.huang@...eadtrum.com:wq>

It is no need to find the very beginning of the area within
alloc_vmap_area, which can be done by judging each node during the process

Signed-off-by: Zhaoyang Huang <zhaoyang.huang@...eadtrum.com>
---
 mm/vmalloc.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 34a1c3e..f833e07 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -459,9 +459,16 @@ static struct vmap_area *alloc_vmap_area(unsigned long size,
 
 		while (n) {
 			struct vmap_area *tmp;
+			struct vmap_area *tmp_next;
 			tmp = rb_entry(n, struct vmap_area, rb_node);
+			tmp_next = list_next_entry(tmp, list);
 			if (tmp->va_end >= addr) {
 				first = tmp;
+				if (ALIGN(tmp->va_end, align) + size
+						< tmp_next->va_start) {
+					addr = ALIGN(tmp->va_end, align);
+					goto found;
+				}
 				if (tmp->va_start <= addr)
 					break;
 				n = n->rb_left;
-- 
1.9.1