path: root/mm
diff options
authorDan Streetman <ddstreet@ieee.org>2014-10-09 15:30:01 -0700
committerAlex Shi <alex.shi@linaro.org>2015-05-11 21:31:00 +0800
commitb900447eb093095e133ffacb6a7de29660e09eae (patch)
tree1858c0987e75154799ce482e46880030cd8d92bd /mm
parentb4f773eb2609e4b4fdf1e4ba11fd5dbc4eb2e655 (diff)
zsmalloc: simplify init_zspage free obj linking
Change zsmalloc init_zspage() logic to iterate through each object on each of its pages, checking the offset to verify the object is on the current page before linking it into the zspage. The current zsmalloc init_zspage free object linking code has logic that relies on there only being one page per zspage when PAGE_SIZE is a multiple of class->size. It calculates the number of objects for the current page, and iterates through all of them plus one, to account for the assumed partial object at the end of the page. While this currently works, the logic can be simplified to just link the object at each successive offset until the offset is larger than PAGE_SIZE, which does not rely on PAGE_SIZE being a multiple of class->size. Signed-off-by: Dan Streetman <ddstreet@ieee.org> Acked-by: Minchan Kim <minchan@kernel.org> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Nitin Gupta <ngupta@vflare.org> Cc: Seth Jennings <sjennings@variantweb.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> (cherry picked from commit 5538c562377580947916b3366898f1eb5f53768e) Signed-off-by: Alex Shi <alex.shi@linaro.org>
Diffstat (limited to 'mm')
1 files changed, 5 insertions, 9 deletions
diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c
index a4556ec316e4..00c28039b06a 100644
--- a/mm/zsmalloc.c
+++ b/mm/zsmalloc.c
@@ -594,7 +594,7 @@ static void init_zspage(struct page *first_page, struct size_class *class)
while (page) {
struct page *next_page;
struct link_free *link;
- unsigned int i, objs_on_page;
+ unsigned int i = 1;
* page->index stores offset of first object starting
@@ -607,14 +607,10 @@ static void init_zspage(struct page *first_page, struct size_class *class)
link = (struct link_free *)kmap_atomic(page) +
off / sizeof(*link);
- objs_on_page = (PAGE_SIZE - off) / class->size;
- for (i = 1; i <= objs_on_page; i++) {
- off += class->size;
- if (off < PAGE_SIZE) {
- link->next = obj_location_to_handle(page, i);
- link += class->size / sizeof(*link);
- }
+ while ((off += class->size) < PAGE_SIZE) {
+ link->next = obj_location_to_handle(page, i++);
+ link += class->size / sizeof(*link);
@@ -626,7 +622,7 @@ static void init_zspage(struct page *first_page, struct size_class *class)
link->next = obj_location_to_handle(next_page, 0);
page = next_page;
- off = (off + class->size) % PAGE_SIZE;
+ off %= PAGE_SIZE;