From: Chen Wandun <chenwandun@xxxxxxxxxx>
Subject: mm/vmalloc: fix numa spreading for large hash tables
Eric Dumazet reported a strange numa spreading info in [1], and found
commit 121e6f3258fe ("mm/vmalloc: hugepage vmalloc mappings") introduced
this issue [2].
Dig into the difference before and after this patch, page allocation has
some difference:
before:
alloc_large_system_hash
__vmalloc
__vmalloc_node(..., NUMA_NO_NODE, ...)
__vmalloc_node_range
__vmalloc_area_node
alloc_page /* because NUMA_NO_NODE, so choose alloc_page branch */
alloc_pages_current
alloc_page_interleave /* can be proved by print policy mode */
after:
alloc_large_system_hash
__vmalloc
__vmalloc_node(..., NUMA_NO_NODE, ...)
__vmalloc_node_range
__vmalloc_area_node
alloc_pages_node /* choose nid by nuam_mem_id() */
__alloc_pages_node(nid, ....)
So after commit 121e6f3258fe ("mm/vmalloc: hugepage vmalloc mappings"), it
will allocate memory in current node instead of interleaving allocate
memory.
[1]
https://lore.kernel.org/linux-mm/CANn89iL6AAyWhfxdHO+jaT075iOa3XcYn9k6JJc7JR2XYn6k_Q@xxxxxxxxxxxxxx/
[2]
https://lore.kernel.org/linux-mm/CANn89iLofTR=AK-QOZY87RdUZENCZUT4O6a0hvhu3_EwRMerOg@xxxxxxxxxxxxxx/
Link: https://lkml.kernel.org/r/20211021080744.874701-2-chenwandun@xxxxxxxxxx
Fixes: 121e6f3258fe ("mm/vmalloc: hugepage vmalloc mappings")
Signed-off-by: Chen Wandun <chenwandun@xxxxxxxxxx>
Reported-by: Eric Dumazet <edumazet@xxxxxxxxxx>
Cc: Shakeel Butt <shakeelb@xxxxxxxxxx>
Cc: Nicholas Piggin <npiggin@xxxxxxxxx>
Cc: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
Cc: Hanjun Guo <guohanjun@xxxxxxxxxx>
Cc: Uladzislau Rezki <urezki@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/vmalloc.c | 15 +++++++++------
1 file changed, 9 insertions(+), 6 deletions(-)
--- a/mm/vmalloc.c~mm-vmalloc-fix-numa-spreading-for-large-hash-tables
+++ a/mm/vmalloc.c
@@ -2816,6 +2816,8 @@ vm_area_alloc_pages(gfp_t gfp, int nid,
unsigned int order, unsigned int nr_pages, struct page **pages)
{
unsigned int nr_allocated = 0;
+ struct page *page;
+ int i;
/*
* For order-0 pages we make use of bulk allocator, if
@@ -2823,7 +2825,7 @@ vm_area_alloc_pages(gfp_t gfp, int nid,
* to fails, fallback to a single page allocator that is
* more permissive.
*/
- if (!order) {
+ if (!order && nid != NUMA_NO_NODE) {
while (nr_allocated < nr_pages) {
unsigned int nr, nr_pages_request;
@@ -2848,7 +2850,7 @@ vm_area_alloc_pages(gfp_t gfp, int nid,
if (nr != nr_pages_request)
break;
}
- } else
+ } else if (order)
/*
* Compound pages required for remap_vmalloc_page if
* high-order pages.
@@ -2856,11 +2858,12 @@ vm_area_alloc_pages(gfp_t gfp, int nid,
gfp |= __GFP_COMP;
/* High-order pages or fallback path if "bulk" fails. */
- while (nr_allocated < nr_pages) {
- struct page *page;
- int i;
- page = alloc_pages_node(nid, gfp, order);
+ while (nr_allocated < nr_pages) {
+ if (nid == NUMA_NO_NODE)
+ page = alloc_pages(gfp, order);
+ else
+ page = alloc_pages_node(nid, gfp, order);
if (unlikely(!page))
break;
_
