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Commit 34bf6ef9 authored by Dave Hansen's avatar Dave Hansen Committed by Pekka Enberg
Browse files

mm: slab/slub: use page->list consistently instead of page->lru 



'struct page' has two list_head fields: 'lru' and 'list'.  Conveniently,
they are unioned together.  This means that code can use them
interchangably, which gets horribly confusing like with this nugget from
slab.c:

>	list_del(&page->lru);
>	if (page->active == cachep->num)
>		list_add(&page->list, &n->slabs_full);

This patch makes the slab and slub code use page->lru universally instead
of mixing ->list and ->lru.

So, the new rule is: page->lru is what the you use if you want to keep
your page on a list.  Don't like the fact that it's not called ->list?
Too bad.

Signed-off-by: default avatarDave Hansen <dave.hansen@linux.intel.com>
Acked-by: default avatarChristoph Lameter <cl@linux.com>
Acked-by: default avatarDavid Rientjes <rientjes@google.com>
Cc: Pekka Enberg <penberg@kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarPekka Enberg <penberg@kernel.org>
parent 5f0985bb

include/linux/mm_types.h

+2 −1
Original line number Diff line number Diff line
@@ -124,6 +124,8 @@ struct page { 
	union {

		struct list_head lru;	/* Pageout list, eg. active_list

					 * protected by zone->lru_lock !

					 * Can be used as a generic list

					 * by the page owner.

					 */

		struct {		/* slub per cpu partial pages */

			struct page *next;	/* Next partial slab */
@@ -136,7 +138,6 @@ struct page { 
#endif

		};



		struct list_head list;	/* slobs list of pages */

		struct slab *slab_page; /* slab fields */

		struct rcu_head rcu_head;	/* Used by SLAB

						 * when destroying via RCU

mm/slab.c

+2 −2
Original line number Diff line number Diff line
@@ -2922,9 +2922,9 @@ retry: 
		/* move slabp to correct slabp list: */

		list_del(&page->lru);

		if (page->active == cachep->num)

			list_add(&page->list, &n->slabs_full);

			list_add(&page->lru, &n->slabs_full);

		else

			list_add(&page->list, &n->slabs_partial);

			list_add(&page->lru, &n->slabs_partial);

	}



must_grow:

mm/slob.c

+5 −5
Original line number Diff line number Diff line
@@ -111,13 +111,13 @@ static inline int slob_page_free(struct page *sp) 


static void set_slob_page_free(struct page *sp, struct list_head *list)

{

	list_add(&sp->list, list);

	list_add(&sp->lru, list);

	__SetPageSlobFree(sp);

}



static inline void clear_slob_page_free(struct page *sp)

{

	list_del(&sp->list);

	list_del(&sp->lru);

	__ClearPageSlobFree(sp);

}
@@ -282,7 +282,7 @@ static void *slob_alloc(size_t size, gfp_t gfp, int align, int node) 


	spin_lock_irqsave(&slob_lock, flags);

	/* Iterate through each partially free page, try to find room */

	list_for_each_entry(sp, slob_list, list) {

	list_for_each_entry(sp, slob_list, lru) {

#ifdef CONFIG_NUMA

		/*

		 * If there's a node specification, search for a partial
@@ -296,7 +296,7 @@ static void *slob_alloc(size_t size, gfp_t gfp, int align, int node) 
			continue;



		/* Attempt to alloc */

		prev = sp->list.prev;

		prev = sp->lru.prev;

		b = slob_page_alloc(sp, size, align);

		if (!b)

			continue;
@@ -322,7 +322,7 @@ static void *slob_alloc(size_t size, gfp_t gfp, int align, int node) 
		spin_lock_irqsave(&slob_lock, flags);

		sp->units = SLOB_UNITS(PAGE_SIZE);

		sp->freelist = b;

		INIT_LIST_HEAD(&sp->list);

		INIT_LIST_HEAD(&sp->lru);

		set_slob(b, SLOB_UNITS(PAGE_SIZE), b + SLOB_UNITS(PAGE_SIZE));

		set_slob_page_free(sp, slob_list);

		b = slob_page_alloc(sp, size, align);