lkml.org 
[lkml]   [2014]   [Nov]   [21]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v2] mm/zsmalloc: avoid duplicate assignment of prev_class
Date
In zs_create_pool(), prev_class is assigned (ZS_SIZE_CLASSES - 1)
times. And the prev_class only references to the previous size_class.
So we do not need unnecessary assignement.

This patch assigns *prev_class* when a new size_class structure
is allocated and uses prev_class to check whether the first class
has been allocated.

Signed-off-by: Mahendran Ganesh <opensource.ganesh@gmail.com>

---
v1 -> v2:
- follow Dan Streetman's advise to use prev_class to
check whether the first class has been allocated
- follow Minchan Kim's advise to remove uninitialized_var()
---
mm/zsmalloc.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c
index b3b57ef..810eda1 100644
--- a/mm/zsmalloc.c
+++ b/mm/zsmalloc.c
@@ -970,7 +970,7 @@ struct zs_pool *zs_create_pool(gfp_t flags)
int size;
int pages_per_zspage;
struct size_class *class;
- struct size_class *prev_class;
+ struct size_class *prev_class = NULL;

size = ZS_MIN_ALLOC_SIZE + i * ZS_SIZE_CLASS_DELTA;
if (size > ZS_MAX_ALLOC_SIZE)
@@ -986,8 +986,7 @@ struct zs_pool *zs_create_pool(gfp_t flags)
* characteristics. So, we makes size_class point to
* previous size_class if possible.
*/
- if (i < ZS_SIZE_CLASSES - 1) {
- prev_class = pool->size_class[i + 1];
+ if (prev_class) {
if (can_merge(prev_class, size, pages_per_zspage)) {
pool->size_class[i] = prev_class;
continue;
@@ -1003,6 +1002,8 @@ struct zs_pool *zs_create_pool(gfp_t flags)
class->pages_per_zspage = pages_per_zspage;
spin_lock_init(&class->lock);
pool->size_class[i] = class;
+
+ prev_class = class;
}

pool->flags = flags;
--
1.7.9.5


\
 
 \ /
  Last update: 2014-11-21 15:21    [W:0.036 / U:2.240 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site