On Thu, 21 Oct 2021 16:07:44 +0800 Chen Wandun [off-list ref] wrote:

It

What is "it"?

will cause significant performance regressions in some situations
as Andrew mentioned in [1]. The main situation is vmalloc, vmalloc
will allocate pages with NUMA_NO_NODE by default, that will result
in alloc page one by one;

In order to solve this, __alloc_pages_bulk and mempolicy should be
considered at the same time.

1) If node is specified in memory allocation request, it will alloc
all pages by __alloc_pages_bulk.

2) If interleaving allocate memory, it will cauculate how many pages
should be allocated in each node, and use __alloc_pages_bulk to alloc
pages in each node.

This v3 patch didn't incorporate my two fixes, below.  It is usual to
incorporate such fixes prior to resending.  I have retained those two
fixes, now against v3.


From: Andrew Morton <akpm@linux-foundation.org>
Subject: mm-vmalloc-introduce-alloc_pages_bulk_array_mempolicy-to-accelerate-memory-allocation-fix

make two functions static

Cc: Chen Wandun <redacted>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Hanjun Guo <guohanjun@huawei.com>
Cc: Kefeng Wang <redacted>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Shakeel Butt <redacted>
Cc: Uladzislau Rezki (Sony) <urezki@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/mempolicy.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/mm/mempolicy.c~mm-vmalloc-introduce-alloc_pages_bulk_array_mempolicy-to-accelerate-memory-allocation-fix
+++ a/mm/mempolicy.c

@@ -2196,7 +2196,7 @@ struct page *alloc_pages(gfp_t gfp, unsi
 }
 EXPORT_SYMBOL(alloc_pages);
 
-unsigned long alloc_pages_bulk_array_interleave(gfp_t gfp,
+static unsigned long alloc_pages_bulk_array_interleave(gfp_t gfp,
 		struct mempolicy *pol, unsigned long nr_pages,
 		struct page **page_array)
 {

@@ -2231,7 +2231,7 @@ unsigned long alloc_pages_bulk_array_int
 	return total_allocated;
 }
 
-unsigned long alloc_pages_bulk_array_preferred_many(gfp_t gfp, int nid,
+static unsigned long alloc_pages_bulk_array_preferred_many(gfp_t gfp, int nid,
 		struct mempolicy *pol, unsigned long nr_pages,
 		struct page **page_array)
 {

_




From: Andrew Morton <akpm@linux-foundation.org>
Subject: mm-vmalloc-introduce-alloc_pages_bulk_array_mempolicy-to-accelerate-memory-allocation-fix-2

fix CONFIG_NUMA=n build.  alloc_pages_bulk_array_mempolicy() was undefined

Cc: Chen Wandun <redacted>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Hanjun Guo <guohanjun@huawei.com>
Cc: Kefeng Wang <redacted>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Uladzislau Rezki (Sony) <urezki@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/vmalloc.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/mm/vmalloc.c~mm-vmalloc-introduce-alloc_pages_bulk_array_mempolicy-to-accelerate-memory-allocation-fix-2
+++ a/mm/vmalloc.c

@@ -2860,7 +2860,7 @@ vm_area_alloc_pages(gfp_t gfp, int nid,
 			 * otherwise memory may be allocated in only one node,
 			 * but mempolcy want to alloc memory by interleaving.
 			 */
-			if (nid == NUMA_NO_NODE)
+			if (IS_ENABLED(CONFIG_NUMA) && nid == NUMA_NO_NODE)
 				nr = alloc_pages_bulk_array_mempolicy(gfp,
 							nr_pages_request,
 							pages + nr_allocated);

_