We had used page->lru to link the component pages (except the first
page) of a zspage, and used INIT_LIST_HEAD(&page->lru) to init it.
Therefore, to get the last page's next page, which is NULL, we had to
use page flag PG_Private_2 to identify it.
But now, we use page->freelist to link all of the pages in zspage and
init the page->freelist as NULL for last page, so no need to use
PG_Private_2 anymore.
This patch is to remove redundant SetPagePrivate2 in create_page_chain
and ClearPagePrivate2 in reset_page(). Maybe can save few cycles for
migration of zsmalloc page :)
Signed-off-by: Yisheng Xie <xieyisheng1@xxxxxxxxxx>
---
mm/zsmalloc.c | 6 +-----
1 file changed, 1 insertion(+), 5 deletions(-)
diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c
index 9cc3c0b..aa90f14 100644
--- a/mm/zsmalloc.c
+++ b/mm/zsmalloc.c
@@ -24,7 +24,6 @@
*
* Usage of struct page flags:
* PG_private: identifies the first component page
- * PG_private2: identifies the last component page
* PG_owner_priv_1: indentifies the huge component page
*
*/
@@ -938,7 +937,6 @@ static void reset_page(struct page *page)
{
__ClearPageMovable(page);
ClearPagePrivate(page);
- ClearPagePrivate2(page);
set_page_private(page, 0);
page_mapcount_reset(page);
ClearPageHugeObject(page);
@@ -1085,7 +1083,7 @@ static void create_page_chain(struct size_class *class, struct zspage *zspage,
* 2. each sub-page point to zspage using page->private
*
* we set PG_private to identify the first page (i.e. no other sub-page
- * has this flag set) and PG_private_2 to identify the last page.
+ * has this flag set).
*/
for (i = 0; i < nr_pages; i++) {
page = pages[i];
@@ -1100,8 +1098,6 @@ static void create_page_chain(struct size_class *class, struct zspage *zspage,
} else {
prev_page->freelist = page;
}
- if (i == nr_pages - 1)
- SetPagePrivate2(page);
prev_page = page;
}
}
--
1.7.12.4
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