[PATCH] mm: Add vmalloc_user_node()

From: Matthew Wilcox (Oracle)
Date: Sun Aug 20 2023 - 15:43:36 EST


Allow memory to be allocated on a specified node. Use it in the
perf ring-buffer code.

Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
---
I was looking at the perf ringbuffer code for other reasons, and I noticed
that everything else gets allocated on the specified node ... except
there's no way to do this for vmalloc. I assume it'd be helpful here too.

include/linux/vmalloc.h | 17 ++++++++++++++++-
kernel/events/ring_buffer.c | 2 +-
mm/vmalloc.c | 9 +++++----
3 files changed, 22 insertions(+), 6 deletions(-)

diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h
index c720be70c8dd..030bfe1a60ab 100644
--- a/include/linux/vmalloc.h
+++ b/include/linux/vmalloc.h
@@ -6,6 +6,7 @@
#include <linux/init.h>
#include <linux/list.h>
#include <linux/llist.h>
+#include <linux/numa.h>
#include <asm/page.h> /* pgprot_t */
#include <linux/rbtree.h>
#include <linux/overflow.h>
@@ -139,7 +140,7 @@ static inline unsigned long vmalloc_nr_pages(void) { return 0; }

extern void *vmalloc(unsigned long size) __alloc_size(1);
extern void *vzalloc(unsigned long size) __alloc_size(1);
-extern void *vmalloc_user(unsigned long size) __alloc_size(1);
+extern void *vmalloc_user_node(unsigned long size, int node) __alloc_size(1);
extern void *vmalloc_node(unsigned long size, int node) __alloc_size(1);
extern void *vzalloc_node(unsigned long size, int node) __alloc_size(1);
extern void *vmalloc_32(unsigned long size) __alloc_size(1);
@@ -158,6 +159,20 @@ extern void *vmalloc_array(size_t n, size_t size) __alloc_size(1, 2);
extern void *__vcalloc(size_t n, size_t size, gfp_t flags) __alloc_size(1, 2);
extern void *vcalloc(size_t n, size_t size) __alloc_size(1, 2);

+/**
+ * vmalloc_user - allocate zeroed virtually contiguous memory for userspace
+ * @size: allocation size
+ *
+ * The resulting memory area is zeroed so it can be mapped to userspace
+ * without leaking data.
+ *
+ * Return: pointer to the allocated memory or %NULL on error
+ */
+static inline void *vmalloc_user(size_t size)
+{
+ return vmalloc_user_node(size, NUMA_NO_NODE);
+}
+
extern void vfree(const void *addr);
extern void vfree_atomic(const void *addr);

diff --git a/kernel/events/ring_buffer.c b/kernel/events/ring_buffer.c
index cc90d5299005..c73add132618 100644
--- a/kernel/events/ring_buffer.c
+++ b/kernel/events/ring_buffer.c
@@ -918,7 +918,7 @@ struct perf_buffer *rb_alloc(int nr_pages, long watermark, int cpu, int flags)

INIT_WORK(&rb->work, rb_free_work);

- all_buf = vmalloc_user((nr_pages + 1) * PAGE_SIZE);
+ all_buf = vmalloc_user_node((nr_pages + 1) * PAGE_SIZE, node);
if (!all_buf)
goto fail_all_buf;

diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 228a4a5312f2..3616bfe4348f 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -3461,22 +3461,23 @@ void *vzalloc(unsigned long size)
EXPORT_SYMBOL(vzalloc);

/**
- * vmalloc_user - allocate zeroed virtually contiguous memory for userspace
+ * vmalloc_user_node - allocate zeroed virtually contiguous memory for userspace
* @size: allocation size
+ * @node: NUMA node
*
* The resulting memory area is zeroed so it can be mapped to userspace
* without leaking data.
*
* Return: pointer to the allocated memory or %NULL on error
*/
-void *vmalloc_user(unsigned long size)
+void *vmalloc_user_node(unsigned long size, int node)
{
return __vmalloc_node_range(size, SHMLBA, VMALLOC_START, VMALLOC_END,
GFP_KERNEL | __GFP_ZERO, PAGE_KERNEL,
- VM_USERMAP, NUMA_NO_NODE,
+ VM_USERMAP, node,
__builtin_return_address(0));
}
-EXPORT_SYMBOL(vmalloc_user);
+EXPORT_SYMBOL(vmalloc_user_node);

/**
* vmalloc_node - allocate memory on a specific node
--
2.40.1