From: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
My recent patch "mm, hugetlb: use memory policy when available" added some
bloat to hugetlb.o. This patch aims to get some of the bloat back,
especially when NUMA is not in play.
It does this with an implicit #ifdef and marking some things static that
should have been static in my first patch. It also makes the warnings
only VM_WARN_ON()s. They were responsible for a pretty big chunk of the
bloat.
Doing this gets our NUMA=n text size back to a wee bit _below_ where we
started before the original patch.
It also shaves a bit of space off the NUMA=y case, but not much. Enforcing
the mempolicy definitely takes some text and it's hard to avoid.
size(1) output:
text data bss dec hex filename
30745 3433 2492 36670 8f3e hugetlb.o.nonuma.baseline
31305 3755 2492 37552 92b0 hugetlb.o.nonuma.patch1
30713 3433 2492 36638 8f1e hugetlb.o.nonuma.patch2 (this patch)
25235 473 41276 66984 105a8 hugetlb.o.numa.baseline
25715 475 41276 67466 1078a hugetlb.o.numa.patch1
25491 473 41276 67240 106a8 hugetlb.o.numa.patch2 (this patch)
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx>
Cc: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
Cc: Hillf Danton <hillf.zj@xxxxxxxxxxxxxxx>
Cc: David Rientjes <rientjes@xxxxxxxxxx>
Cc: linux-mm@xxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Signed-off-by: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
---
b/mm/hugetlb.c | 18 +++++++++++++-----
1 file changed, 13 insertions(+), 5 deletions(-)
diff -puN mm/hugetlb.c~hugetlbfs-decrapify-with-no-numa mm/hugetlb.c
--- a/mm/hugetlb.c~hugetlbfs-decrapify-with-no-numa 2015-10-20 16:47:24.501877643 -0700
+++ b/mm/hugetlb.c 2015-10-20 16:52:33.060946354 -0700
@@ -1455,9 +1455,14 @@ static struct page *__hugetlb_alloc_budd
/*
* We need a VMA to get a memory policy. If we do not
- * have one, we use the 'nid' argument
+ * have one, we use the 'nid' argument.
+ *
+ * The mempolicy stuff below has some non-inlined bits
+ * and calls ->vm_ops. That makes it hard to optimize at
+ * compile-time, even when NUMA is off and it does
+ * nothing. This helps the compiler optimize it out.
*/
- if (!vma) {
+ if (!IS_ENABLED(CONFIG_NUMA) || !vma) {
/*
* If a specific node is requested, make sure to
* get memory from there, but only when a node
@@ -1474,7 +1479,8 @@ static struct page *__hugetlb_alloc_budd
/*
* OK, so we have a VMA. Fetch the mempolicy and try to
- * allocate a huge page with it.
+ * allocate a huge page with it. We will only reach this
+ * when CONFIG_NUMA=y.
*/
do {
struct page *page;
@@ -1515,8 +1521,8 @@ static struct page *__alloc_buddy_huge_p
return NULL;
if (vma || addr) {
- WARN_ON_ONCE(!addr || addr == -1);
- WARN_ON_ONCE(nid != NUMA_NO_NODE);
+ VM_WARN_ON_ONCE(!addr || addr == -1);
+ VM_WARN_ON_ONCE(nid != NUMA_NO_NODE);
}
/*
* Assume we will successfully allocate the surplus page to
@@ -1580,6 +1586,7 @@ static struct page *__alloc_buddy_huge_p
* NUMA_NO_NODE, which means that it may be allocated
* anywhere.
*/
+static
struct page *__alloc_buddy_huge_page_no_mpol(struct hstate *h, int nid)
{
unsigned long addr = -1;
@@ -1590,6 +1597,7 @@ struct page *__alloc_buddy_huge_page_no_
/*
* Use the VMA's mpolicy to allocate a huge page from the buddy.
*/
+static
struct page *__alloc_buddy_huge_page_with_mpol(struct hstate *h,
struct vm_area_struct *vma, unsigned long addr)
{
_
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@xxxxxxxxx. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>