From: Pekka Enberg <penberg@cs.helsinki.fi>
The current implementation of cache_grow() has to either (1) use pre-allocated
memory for the slab or (2) allocate the memory itself which makes the error
paths messy. Move __GFP_NO_GROW and __GFP_WAIT processing to kmem_getpages()
and introduce a new __cache_grow() variant that expects the memory for a new
slab to always be handed over in the 'objp' parameter.
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
---
diff --git a/mm/slab.c b/mm/slab.c
index c610062..856856c 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -1597,6 +1597,14 @@ static int __init cpucache_init(void)
}
__initcall(cpucache_init);
+static void kmem_flagcheck(struct kmem_cache *cachep, gfp_t flags)
+{
+ if (flags & GFP_DMA)
+ BUG_ON(!(cachep->gfpflags & GFP_DMA));
+ else
+ BUG_ON(cachep->gfpflags & GFP_DMA);
+}
+
/*
* Interface to system's page allocator. No need to hold the cache-lock.
*
@@ -1608,8 +1616,22 @@ static void *kmem_getpages(struct kmem_c
{
struct page *page;
int nr_pages;
+ void *ret;
int i;
+ if (flags & __GFP_NO_GROW)
+ return NULL;
+
+ /*
+ * The test for missing atomic flag is performed here, rather than
+ * the more obvious place, simply to reduce the critical path length
+ * in kmem_cache_alloc(). If a caller is seriously mis-behaving they
+ * will eventually be caught here (where it matters).
+ */
+ kmem_flagcheck(cachep, flags);
+ if (flags & __GFP_WAIT)
+ local_irq_enable();
+
#ifndef CONFIG_MMU
/*
* Nommu uses slab's for process anonymous memory allocations, and thus
@@ -1621,8 +1643,10 @@ #endif
flags |= cachep->gfpflags;
page = alloc_pages_node(nodeid, flags, cachep->gfporder);
- if (!page)
- return NULL;
+ if (!page) {
+ ret = NULL;
+ goto out;
+ }
nr_pages = (1 << cachep->gfporder);
if (cachep->flags & SLAB_RECL...
