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>

1 files changed, 25 insertions, 24 deletions

diff --git a/mm/slab.c b/mm/slab.c
index 284ab737faee..e9eaa8fce231 100644
--- 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 @@ free_done:
                 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);
                 }