page allocator: do not check NUMA node ID when the caller knows the node is valid
Callers of alloc_pages_node() can optionally specify -1 as a node to mean
"allocate from the current node". However, a number of the callers in
fast paths know for a fact their node is valid. To avoid a comparison and
branch, this patch adds alloc_pages_exact_node() that only checks the nid
with VM_BUG_ON(). Callers that know their node is valid are then
converted.
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: Christoph Lameter <cl@linux-foundation.org>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reviewed-by: Pekka Enberg <penberg@cs.helsinki.fi>
Acked-by: Paul Mundt <lethal@linux-sh.org> [for the SLOB NUMA bits]
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Dave Hansen <dave@linux.vnet.ibm.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/filemap.c b/mm/filemap.c
index 6846a90..2239671 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -521,7 +521,7 @@
{
if (cpuset_do_page_mem_spread()) {
int n = cpuset_mem_spread_node();
- return alloc_pages_node(n, gfp, 0);
+ return alloc_pages_exact_node(n, gfp, 0);
}
return alloc_pages(gfp, 0);
}
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index e83ad2c..2f8241f 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -630,7 +630,7 @@
if (h->order >= MAX_ORDER)
return NULL;
- page = alloc_pages_node(nid,
+ page = alloc_pages_exact_node(nid,
htlb_alloc_mask|__GFP_COMP|__GFP_THISNODE|
__GFP_REPEAT|__GFP_NOWARN,
huge_page_order(h));
@@ -649,7 +649,7 @@
* Use a helper variable to find the next node and then
* copy it back to hugetlb_next_nid afterwards:
* otherwise there's a window in which a racer might
- * pass invalid nid MAX_NUMNODES to alloc_pages_node.
+ * pass invalid nid MAX_NUMNODES to alloc_pages_exact_node.
* But we don't need to use a spin_lock here: it really
* doesn't matter if occasionally a racer chooses the
* same nid as we do. Move nid forward in the mask even
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 46bdf9d..e08e2c4 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -803,7 +803,7 @@
static struct page *new_node_page(struct page *page, unsigned long node, int **x)
{
- return alloc_pages_node(node, GFP_HIGHUSER_MOVABLE, 0);
+ return alloc_pages_exact_node(node, GFP_HIGHUSER_MOVABLE, 0);
}
/*
diff --git a/mm/migrate.c b/mm/migrate.c
index 068655d..5a24923 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -802,7 +802,7 @@
*result = &pm->status;
- return alloc_pages_node(pm->node,
+ return alloc_pages_exact_node(pm->node,
GFP_HIGHUSER_MOVABLE | GFP_THISNODE, 0);
}
diff --git a/mm/slab.c b/mm/slab.c
index 18e3164..bb3254c 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -1707,7 +1707,7 @@
if (cachep->flags & SLAB_RECLAIM_ACCOUNT)
flags |= __GFP_RECLAIMABLE;
- page = alloc_pages_node(nodeid, flags, cachep->gfporder);
+ page = alloc_pages_exact_node(nodeid, flags, cachep->gfporder);
if (!page)
return NULL;
@@ -3261,7 +3261,7 @@
if (local_flags & __GFP_WAIT)
local_irq_enable();
kmem_flagcheck(cache, flags);
- obj = kmem_getpages(cache, local_flags, -1);
+ obj = kmem_getpages(cache, local_flags, numa_node_id());
if (local_flags & __GFP_WAIT)
local_irq_disable();
if (obj) {
diff --git a/mm/slob.c b/mm/slob.c
index 12f2614..64f6db1 100644
--- a/mm/slob.c
+++ b/mm/slob.c
@@ -46,7 +46,7 @@
* NUMA support in SLOB is fairly simplistic, pushing most of the real
* logic down to the page allocator, and simply doing the node accounting
* on the upper levels. In the event that a node id is explicitly
- * provided, alloc_pages_node() with the specified node id is used
+ * provided, alloc_pages_exact_node() with the specified node id is used
* instead. The common case (or when the node id isn't explicitly provided)
* will default to the current node, as per numa_node_id().
*
@@ -244,7 +244,7 @@
#ifdef CONFIG_NUMA
if (node != -1)
- page = alloc_pages_node(node, gfp, order);
+ page = alloc_pages_exact_node(node, gfp, order);
else
#endif
page = alloc_pages(gfp, order);