On 5/3/12 2:40 AM, Minchan Kim wrote:
It's a overkill to align pool size with PAGE_SIZE to avoid
false-sharing. This patch aligns it with just cache line size.
Signed-off-by: Minchan Kim<minchan@xxxxxxxxxx>
---
drivers/staging/zsmalloc/zsmalloc-main.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/staging/zsmalloc/zsmalloc-main.c b/drivers/staging/zsmalloc/zsmalloc-main.c
index 51074fa..3991b03 100644
--- a/drivers/staging/zsmalloc/zsmalloc-main.c
+++ b/drivers/staging/zsmalloc/zsmalloc-main.c
@@ -489,14 +489,14 @@ fail:
struct zs_pool *zs_create_pool(const char *name, gfp_t flags)
{
- int i, error, ovhd_size;
+ int i, error;
struct zs_pool *pool;
if (!name)
return NULL;
- ovhd_size = roundup(sizeof(*pool), PAGE_SIZE);
- pool = kzalloc(ovhd_size, GFP_KERNEL);
+ pool = kzalloc(ALIGN(sizeof(*pool), cache_line_size()),
+ GFP_KERNEL);
a basic question:
Is rounding off allocation size to cache_line_size enough to ensure
that the object is cache-line-aligned? Isn't it possible that even
though the object size is multiple of cache-line, it may still not be
properly aligned and end up sharing cache line with some other
read-mostly object?
Thanks,
Nitin
if (!pool)
return NULL;
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