slab: use slab_list instead of lru

Currently we use the page->lru list for maintaining lists of slabs.  We
have a list in the page structure (slab_list) that can be used for this
purpose.  Doing so makes the code cleaner since we are not overloading the
lru list.

Use the slab_list instead of the lru list for maintaining lists of slabs.

Link: http://lkml.kernel.org/r/20190402230545.2929-7-tobin@kernel.org
Signed-off-by: Tobin C. Harding <tobin@kernel.org>
Acked-by: Christoph Lameter <cl@linux.com>
Reviewed-by: Roman Gushchin <guro@fb.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Pekka Enberg <penberg@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/slab.c b/mm/slab.c
index 284ab737faee01f1aa3d3178fa123ff08f8f27bf..e9eaa8fce231194ced1f69aeda1c4cd57a5c814a 100644 (file)
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -1674,8 +1674,8 @@ static void slabs_destroy(struct kmem_cache *cachep, struct list_head *list)
 {
        struct page *page, *n;
 
-       list_for_each_entry_safe(page, n, list, lru) {
-               list_del(&page->lru);
+       list_for_each_entry_safe(page, n, list, slab_list) {
+               list_del(&page->slab_list);
                slab_destroy(cachep, page);
        }
 }
@@ -2231,8 +2231,8 @@ static int drain_freelist(struct kmem_cache *cache,
                        goto out;
                }
 
-               page = list_entry(p, struct page, lru);
-               list_del(&page->lru);
+               page = list_entry(p, struct page, slab_list);
+               list_del(&page->slab_list);
                n->free_slabs--;
                n->total_slabs--;
                /*
@@ -2691,13 +2691,13 @@ static void cache_grow_end(struct kmem_cache *cachep, struct page *page)
        if (!page)
                return;
 
-       INIT_LIST_HEAD(&page->lru);
+       INIT_LIST_HEAD(&page->slab_list);
        n = get_node(cachep, page_to_nid(page));
 
        spin_lock(&n->list_lock);
        n->total_slabs++;
        if (!page->active) {
-               list_add_tail(&page->lru, &(n->slabs_free));
+               list_add_tail(&page->slab_list, &n->slabs_free);
                n->free_slabs++;
        } else
                fixup_slab_list(cachep, n, page, &list);
@@ -2806,9 +2806,9 @@ static inline void fixup_slab_list(struct kmem_cache *cachep,
                                void **list)
 {
        /* move slabp to correct slabp list: */
-       list_del(&page->lru);
+       list_del(&page->slab_list);
        if (page->active == cachep->num) {
-               list_add(&page->lru, &n->slabs_full);
+               list_add(&page->slab_list, &n->slabs_full);
                if (OBJFREELIST_SLAB(cachep)) {
 #if DEBUG
                        /* Poisoning will be done without holding the lock */
@@ -2822,7 +2822,7 @@ static inline void fixup_slab_list(struct kmem_cache *cachep,
                        page->freelist = NULL;
                }
        } else
-               list_add(&page->lru, &n->slabs_partial);
+               list_add(&page->slab_list, &n->slabs_partial);
 }
 
 /* Try to find non-pfmemalloc slab if needed */
@@ -2845,20 +2845,20 @@ static noinline struct page *get_valid_first_slab(struct kmem_cache_node *n,
        }
 
        /* Move pfmemalloc slab to the end of list to speed up next search */
-       list_del(&page->lru);
+       list_del(&page->slab_list);
        if (!page->active) {
-               list_add_tail(&page->lru, &n->slabs_free);
+               list_add_tail(&page->slab_list, &n->slabs_free);
                n->free_slabs++;
        } else
-               list_add_tail(&page->lru, &n->slabs_partial);
+               list_add_tail(&page->slab_list, &n->slabs_partial);
 
-       list_for_each_entry(page, &n->slabs_partial, lru) {
+       list_for_each_entry(page, &n->slabs_partial, slab_list) {
                if (!PageSlabPfmemalloc(page))
                        return page;
        }
 
        n->free_touched = 1;
-       list_for_each_entry(page, &n->slabs_free, lru) {
+       list_for_each_entry(page, &n->slabs_free, slab_list) {
                if (!PageSlabPfmemalloc(page)) {
                        n->free_slabs--;
                        return page;
@@ -2873,11 +2873,12 @@ static struct page *get_first_slab(struct kmem_cache_node *n, bool pfmemalloc)
        struct page *page;
 
        assert_spin_locked(&n->list_lock);
-       page = list_first_entry_or_null(&n->slabs_partial, struct page, lru);
+       page = list_first_entry_or_null(&n->slabs_partial, struct page,
+                                       slab_list);
        if (!page) {
                n->free_touched = 1;
                page = list_first_entry_or_null(&n->slabs_free, struct page,
-                                               lru);
+                                               slab_list);
                if (page)
                        n->free_slabs--;
        }
@@ -3378,29 +3379,29 @@ static void free_block(struct kmem_cache *cachep, void **objpp,
                objp = objpp[i];
 
                page = virt_to_head_page(objp);
-               list_del(&page->lru);
+               list_del(&page->slab_list);
                check_spinlock_acquired_node(cachep, node);
                slab_put_obj(cachep, page, objp);
                STATS_DEC_ACTIVE(cachep);
 
                /* fixup slab chains */
                if (page->active == 0) {
-                       list_add(&page->lru, &n->slabs_free);
+                       list_add(&page->slab_list, &n->slabs_free);
                        n->free_slabs++;
                } else {
                        /* Unconditionally move a slab to the end of the
                         * partial list on free - maximum time for the
                         * other objects to be freed, too.
                         */
-                       list_add_tail(&page->lru, &n->slabs_partial);
+                       list_add_tail(&page->slab_list, &n->slabs_partial);
                }
        }
 
        while (n->free_objects > n->free_limit && !list_empty(&n->slabs_free)) {
                n->free_objects -= cachep->num;
 
-               page = list_last_entry(&n->slabs_free, struct page, lru);
-               list_move(&page->lru, list);
+               page = list_last_entry(&n->slabs_free, struct page, slab_list);
+               list_move(&page->slab_list, list);
                n->free_slabs--;
                n->total_slabs--;
        }
@@ -3438,7 +3439,7 @@ static void cache_flusharray(struct kmem_cache *cachep, struct array_cache *ac)
                int i = 0;
                struct page *page;
 
-               list_for_each_entry(page, &n->slabs_free, lru) {
+               list_for_each_entry(page, &n->slabs_free, slab_list) {
                        BUG_ON(page->active);
 
                        i++;
@@ -4302,9 +4303,9 @@ static int leaks_show(struct seq_file *m, void *p)
                        check_irq_on();
                        spin_lock_irq(&n->list_lock);
 
-                       list_for_each_entry(page, &n->slabs_full, lru)
+                       list_for_each_entry(page, &n->slabs_full, slab_list)
                                handle_slab(x, cachep, page);
-                       list_for_each_entry(page, &n->slabs_partial, lru)
+                       list_for_each_entry(page, &n->slabs_partial, slab_list)
                                handle_slab(x, cachep, page);
                        spin_unlock_irq(&n->list_lock);
                }