lkml.org 
[lkml]   [2013]   [Aug]   [22]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 09/16] slab: use __GFP_COMP flag for allocating slab pages
Date
If we use 'struct page' of first page as 'struct slab', there is no
advantage not to use __GFP_COMP. So use __GFP_COMP flag for all the cases.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>

diff --git a/mm/slab.c b/mm/slab.c
index ee03eba..855f481 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -1712,15 +1712,6 @@ static struct page *kmem_getpages(struct kmem_cache *cachep, gfp_t flags,
{
struct page *page;
int nr_pages;
- int i;
-
-#ifndef CONFIG_MMU
- /*
- * Nommu uses slab's for process anonymous memory allocations, and thus
- * requires __GFP_COMP to properly refcount higher order allocations
- */
- flags |= __GFP_COMP;
-#endif

flags |= cachep->allocflags;
if (cachep->flags & SLAB_RECLAIM_ACCOUNT)
@@ -1744,12 +1735,9 @@ static struct page *kmem_getpages(struct kmem_cache *cachep, gfp_t flags,
else
add_zone_page_state(page_zone(page),
NR_SLAB_UNRECLAIMABLE, nr_pages);
- for (i = 0; i < nr_pages; i++) {
- __SetPageSlab(page + i);
-
- if (page->pfmemalloc)
- SetPageSlabPfmemalloc(page);
- }
+ __SetPageSlab(page);
+ if (page->pfmemalloc)
+ SetPageSlabPfmemalloc(page);
memcg_bind_pages(cachep, cachep->gfporder);

if (kmemcheck_enabled && !(cachep->flags & SLAB_NOTRACK)) {
@@ -1769,8 +1757,7 @@ static struct page *kmem_getpages(struct kmem_cache *cachep, gfp_t flags,
*/
static void kmem_freepages(struct kmem_cache *cachep, struct page *page)
{
- unsigned long i = (1 << cachep->gfporder);
- const unsigned long nr_freed = i;
+ const unsigned long nr_freed = (1 << cachep->gfporder);

kmemcheck_free_shadow(page, cachep->gfporder);

@@ -1781,12 +1768,9 @@ static void kmem_freepages(struct kmem_cache *cachep, struct page *page)
sub_zone_page_state(page_zone(page),
NR_SLAB_UNRECLAIMABLE, nr_freed);

+ BUG_ON(!PageSlab(page));
__ClearPageSlabPfmemalloc(page);
- while (i--) {
- BUG_ON(!PageSlab(page));
- __ClearPageSlab(page);
- page++;
- }
+ __ClearPageSlab(page);

memcg_release_pages(cachep, cachep->gfporder);
if (current->reclaim_state)
@@ -2350,7 +2334,7 @@ __kmem_cache_create (struct kmem_cache *cachep, unsigned long flags)
cachep->colour = left_over / cachep->colour_off;
cachep->slab_size = slab_size;
cachep->flags = flags;
- cachep->allocflags = 0;
+ cachep->allocflags = __GFP_COMP;
if (CONFIG_ZONE_DMA_FLAG && (flags & SLAB_CACHE_DMA))
cachep->allocflags |= GFP_DMA;
cachep->size = size;
@@ -2717,17 +2701,8 @@ static void slab_put_obj(struct kmem_cache *cachep, struct slab *slabp,
static void slab_map_pages(struct kmem_cache *cache, struct slab *slab,
struct page *page)
{
- int nr_pages;
-
- nr_pages = 1;
- if (likely(!PageCompound(page)))
- nr_pages <<= cache->gfporder;
-
- do {
- page->slab_cache = cache;
- page->slab_page = slab;
- page++;
- } while (--nr_pages);
+ page->slab_cache = cache;
+ page->slab_page = slab;
}

/*
--
1.7.9.5


\
 
 \ /
  Last update: 2013-08-22 11:21    [W:0.207 / U:13.148 seconds]
©2003-2017 Jasper Spaans. hosted at Digital OceanAdvertise on this site