mm: Enable SLUB for RT
Make SLUB RT aware and remove the restriction in Kconfig.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/mm/slub.c b/mm/slub.c
index 57707f0..f63bb78 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -1071,7 +1071,7 @@
{
struct kmem_cache_node *n = get_node(s, page_to_nid(page));
- spin_lock_irqsave(&n->list_lock, *flags);
+ raw_spin_lock_irqsave(&n->list_lock, *flags);
slab_lock(page);
if (!check_slab(s, page))
@@ -1119,7 +1119,7 @@
fail:
slab_unlock(page);
- spin_unlock_irqrestore(&n->list_lock, *flags);
+ raw_spin_unlock_irqrestore(&n->list_lock, *flags);
slab_fix(s, "Object at 0x%p not freed", object);
return NULL;
}
@@ -1254,6 +1254,12 @@
#endif /* CONFIG_SLUB_DEBUG */
+struct slub_free_list {
+ raw_spinlock_t lock;
+ struct list_head list;
+};
+static DEFINE_PER_CPU(struct slub_free_list, slub_free_list);
+
/*
* Slab allocation and freeing
*/
@@ -1278,7 +1284,11 @@
flags &= gfp_allowed_mask;
+#ifdef CONFIG_PREEMPT_RT_FULL
+ if (system_state == SYSTEM_RUNNING)
+#else
if (flags & __GFP_WAIT)
+#endif
local_irq_enable();
flags |= s->allocflags;
@@ -1318,7 +1328,11 @@
kmemcheck_mark_unallocated_pages(page, pages);
}
+#ifdef CONFIG_PREEMPT_RT_FULL
+ if (system_state == SYSTEM_RUNNING)
+#else
if (flags & __GFP_WAIT)
+#endif
local_irq_disable();
if (!page)
return NULL;
@@ -1415,6 +1429,16 @@
__free_memcg_kmem_pages(page, order);
}
+static void free_delayed(struct kmem_cache *s, struct list_head *h)
+{
+ while(!list_empty(h)) {
+ struct page *page = list_first_entry(h, struct page, lru);
+
+ list_del(&page->lru);
+ __free_slab(s, page);
+ }
+}
+
#define need_reserve_slab_rcu \
(sizeof(((struct page *)NULL)->lru) < sizeof(struct rcu_head))
@@ -1449,6 +1473,12 @@
}
call_rcu(head, rcu_free_slab);
+ } else if (irqs_disabled()) {
+ struct slub_free_list *f = &__get_cpu_var(slub_free_list);
+
+ raw_spin_lock(&f->lock);
+ list_add(&page->lru, &f->list);
+ raw_spin_unlock(&f->lock);
} else
__free_slab(s, page);
}
@@ -1553,7 +1583,7 @@
if (!n || !n->nr_partial)
return NULL;
- spin_lock(&n->list_lock);
+ raw_spin_lock(&n->list_lock);
list_for_each_entry_safe(page, page2, &n->partial, lru) {
void *t;
@@ -1577,7 +1607,7 @@
break;
}
- spin_unlock(&n->list_lock);
+ raw_spin_unlock(&n->list_lock);
return object;
}
@@ -1819,7 +1849,7 @@
* that acquire_slab() will see a slab page that
* is frozen
*/
- spin_lock(&n->list_lock);
+ raw_spin_lock(&n->list_lock);
}
} else {
m = M_FULL;
@@ -1830,7 +1860,7 @@
* slabs from diagnostic functions will not see
* any frozen slabs.
*/
- spin_lock(&n->list_lock);
+ raw_spin_lock(&n->list_lock);
}
}
@@ -1865,7 +1895,7 @@
goto redo;
if (lock)
- spin_unlock(&n->list_lock);
+ raw_spin_unlock(&n->list_lock);
if (m == M_FREE) {
stat(s, DEACTIVATE_EMPTY);
@@ -1896,10 +1926,10 @@
n2 = get_node(s, page_to_nid(page));
if (n != n2) {
if (n)
- spin_unlock(&n->list_lock);
+ raw_spin_unlock(&n->list_lock);
n = n2;
- spin_lock(&n->list_lock);
+ raw_spin_lock(&n->list_lock);
}
do {
@@ -1928,7 +1958,7 @@
}
if (n)
- spin_unlock(&n->list_lock);
+ raw_spin_unlock(&n->list_lock);
while (discard_page) {
page = discard_page;
@@ -1964,14 +1994,21 @@
pobjects = oldpage->pobjects;
pages = oldpage->pages;
if (drain && pobjects > s->cpu_partial) {
+ struct slub_free_list *f;
unsigned long flags;
+ LIST_HEAD(tofree);
/*
* partial array is full. Move the existing
* set to the per node partial list.
*/
local_irq_save(flags);
unfreeze_partials(s, this_cpu_ptr(s->cpu_slab));
+ f = &__get_cpu_var(slub_free_list);
+ raw_spin_lock(&f->lock);
+ list_splice_init(&f->list, &tofree);
+ raw_spin_unlock(&f->lock);
local_irq_restore(flags);
+ free_delayed(s, &tofree);
oldpage = NULL;
pobjects = 0;
pages = 0;
@@ -2033,7 +2070,22 @@
static void flush_all(struct kmem_cache *s)
{
+ LIST_HEAD(tofree);
+ int cpu;
+
on_each_cpu_cond(has_cpu_slab, flush_cpu_slab, s, 1, GFP_ATOMIC);
+ for_each_online_cpu(cpu) {
+ struct slub_free_list *f;
+
+ if (!has_cpu_slab(cpu, s))
+ continue;
+
+ f = &per_cpu(slub_free_list, cpu);
+ raw_spin_lock_irq(&f->lock);
+ list_splice_init(&f->list, &tofree);
+ raw_spin_unlock_irq(&f->lock);
+ free_delayed(s, &tofree);
+ }
}
/*
@@ -2061,10 +2113,10 @@
unsigned long x = 0;
struct page *page;
- spin_lock_irqsave(&n->list_lock, flags);
+ raw_spin_lock_irqsave(&n->list_lock, flags);
list_for_each_entry(page, &n->partial, lru)
x += get_count(page);
- spin_unlock_irqrestore(&n->list_lock, flags);
+ raw_spin_unlock_irqrestore(&n->list_lock, flags);
return x;
}
@@ -2207,9 +2259,11 @@
static void *__slab_alloc(struct kmem_cache *s, gfp_t gfpflags, int node,
unsigned long addr, struct kmem_cache_cpu *c)
{
+ struct slub_free_list *f;
void *freelist;
struct page *page;
unsigned long flags;
+ LIST_HEAD(tofree);
local_irq_save(flags);
#ifdef CONFIG_PREEMPT
@@ -2272,7 +2326,13 @@
VM_BUG_ON(!c->page->frozen);
c->freelist = get_freepointer(s, freelist);
c->tid = next_tid(c->tid);
+out:
+ f = &__get_cpu_var(slub_free_list);
+ raw_spin_lock(&f->lock);
+ list_splice_init(&f->list, &tofree);
+ raw_spin_unlock(&f->lock);
local_irq_restore(flags);
+ free_delayed(s, &tofree);
return freelist;
new_slab:
@@ -2290,9 +2350,7 @@
if (unlikely(!freelist)) {
if (!(gfpflags & __GFP_NOWARN) && printk_ratelimit())
slab_out_of_memory(s, gfpflags, node);
-
- local_irq_restore(flags);
- return NULL;
+ goto out;
}
page = c->page;
@@ -2306,8 +2364,7 @@
deactivate_slab(s, page, get_freepointer(s, freelist));
c->page = NULL;
c->freelist = NULL;
- local_irq_restore(flags);
- return freelist;
+ goto out;
}
/*
@@ -2484,7 +2541,7 @@
do {
if (unlikely(n)) {
- spin_unlock_irqrestore(&n->list_lock, flags);
+ raw_spin_unlock_irqrestore(&n->list_lock, flags);
n = NULL;
}
prior = page->freelist;
@@ -2514,7 +2571,7 @@
* Otherwise the list_lock will synchronize with
* other processors updating the list of slabs.
*/
- spin_lock_irqsave(&n->list_lock, flags);
+ raw_spin_lock_irqsave(&n->list_lock, flags);
}
}
@@ -2555,7 +2612,7 @@
add_partial(n, page, DEACTIVATE_TO_TAIL);
stat(s, FREE_ADD_PARTIAL);
}
- spin_unlock_irqrestore(&n->list_lock, flags);
+ raw_spin_unlock_irqrestore(&n->list_lock, flags);
return;
slab_empty:
@@ -2569,7 +2626,7 @@
/* Slab must be on the full list */
remove_full(s, page);
- spin_unlock_irqrestore(&n->list_lock, flags);
+ raw_spin_unlock_irqrestore(&n->list_lock, flags);
stat(s, FREE_SLAB);
discard_slab(s, page);
}
@@ -2771,7 +2828,7 @@
init_kmem_cache_node(struct kmem_cache_node *n)
{
n->nr_partial = 0;
- spin_lock_init(&n->list_lock);
+ raw_spin_lock_init(&n->list_lock);
INIT_LIST_HEAD(&n->partial);
#ifdef CONFIG_SLUB_DEBUG
atomic_long_set(&n->nr_slabs, 0);
@@ -3393,7 +3450,7 @@
for (i = 0; i < objects; i++)
INIT_LIST_HEAD(slabs_by_inuse + i);
- spin_lock_irqsave(&n->list_lock, flags);
+ raw_spin_lock_irqsave(&n->list_lock, flags);
/*
* Build lists indexed by the items in use in each slab.
@@ -3414,7 +3471,7 @@
for (i = objects - 1; i > 0; i--)
list_splice(slabs_by_inuse + i, n->partial.prev);
- spin_unlock_irqrestore(&n->list_lock, flags);
+ raw_spin_unlock_irqrestore(&n->list_lock, flags);
/* Release empty slabs */
list_for_each_entry_safe(page, t, slabs_by_inuse, lru)
@@ -3590,6 +3647,12 @@
{
static __initdata struct kmem_cache boot_kmem_cache,
boot_kmem_cache_node;
+ int cpu;
+
+ for_each_possible_cpu(cpu) {
+ raw_spin_lock_init(&per_cpu(slub_free_list, cpu).lock);
+ INIT_LIST_HEAD(&per_cpu(slub_free_list, cpu).list);
+ }
if (debug_guardpage_minorder())
slub_max_order = 0;
@@ -3894,7 +3957,7 @@
struct page *page;
unsigned long flags;
- spin_lock_irqsave(&n->list_lock, flags);
+ raw_spin_lock_irqsave(&n->list_lock, flags);
list_for_each_entry(page, &n->partial, lru) {
validate_slab_slab(s, page, map);
@@ -3917,7 +3980,7 @@
atomic_long_read(&n->nr_slabs));
out:
- spin_unlock_irqrestore(&n->list_lock, flags);
+ raw_spin_unlock_irqrestore(&n->list_lock, flags);
return count;
}
@@ -4107,12 +4170,12 @@
if (!atomic_long_read(&n->nr_slabs))
continue;
- spin_lock_irqsave(&n->list_lock, flags);
+ raw_spin_lock_irqsave(&n->list_lock, flags);
list_for_each_entry(page, &n->partial, lru)
process_slab(&t, s, page, alloc, map);
list_for_each_entry(page, &n->full, lru)
process_slab(&t, s, page, alloc, map);
- spin_unlock_irqrestore(&n->list_lock, flags);
+ raw_spin_unlock_irqrestore(&n->list_lock, flags);
}
for (i = 0; i < t.count; i++) {