mm, slub: restore irqs around calling new_slab()

allocate_slab() currently re-enables irqs before calling to the page allocator.
It depends on gfpflags_allow_blocking() to determine if it's safe to do so.
Now we can instead simply restore irq before calling it through new_slab().
The other caller early_kmem_cache_node_alloc() is unaffected by this.

Signed-off-by: Vlastimil Babka <vbabka@suse.cz>

diff --git a/mm/slub.c b/mm/slub.c
index 4d1f3e4a59516e060693e2b0c406d12b98fa8cbb..7798ba1c614f1ef7a3199e8e39763a1a3ea471da 100644 (file)
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -1809,9 +1809,6 @@ static struct page *allocate_slab(struct kmem_cache *s, gfp_t flags, int node)
 
        flags &= gfp_allowed_mask;
 
-       if (gfpflags_allow_blocking(flags))
-               local_irq_enable();
-
        flags |= s->allocflags;
 
        /*
@@ -1870,8 +1867,6 @@ static struct page *allocate_slab(struct kmem_cache *s, gfp_t flags, int node)
        page->frozen = 1;
 
 out:
-       if (gfpflags_allow_blocking(flags))
-               local_irq_disable();
        if (!page)
                return NULL;
 
@@ -2812,16 +2807,17 @@ new_objects:
                goto check_new_page;
        }
 
+       local_irq_restore(flags);
        put_cpu_ptr(s->cpu_slab);
        page = new_slab(s, gfpflags, node);
        c = get_cpu_ptr(s->cpu_slab);
 
        if (unlikely(!page)) {
-               local_irq_restore(flags);
                slab_out_of_memory(s, gfpflags, node);
                return NULL;
        }
 
+       local_irq_save(flags);
        if (c->page)
                flush_slab(s, c);