[PATCH 1/3] mm/util: Add kvmalloc_node_caller

* [PATCH 1/3] mm/util: Add kvmalloc_node_caller
@ 2021-05-10 15:02 Matthew Wilcox (Oracle)
  2021-05-10 15:02 ` [PATCH 2/3] mm/vmalloc: Use kvmalloc to allocate the table of pages Matthew Wilcox (Oracle)
  2021-05-10 15:02 ` [PATCH 3/3] MAINTAINERS: Add Vlad Rezki as vmalloc maintainer Matthew Wilcox (Oracle)
  0 siblings, 2 replies; 3+ messages in thread
From: Matthew Wilcox (Oracle) @ 2021-05-10 15:02 UTC (permalink / raw)
  To: linux-mm; +Cc: Matthew Wilcox (Oracle), David Rientjes

Allow the caller of kvmalloc to specify who counts as the allocator
of the memory instead of assuming it's the immediate caller.  Also
reword the kernel-doc for kvmalloc_node() to document the semantics
of the function rather than its implementation.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: David Rientjes <rientjes@google.com>
---
 include/linux/mm.h   |  4 +++-
 include/linux/slab.h |  2 ++
 mm/util.c            | 51 ++++++++++++++++++++++++--------------------
 3 files changed, 33 insertions(+), 24 deletions(-)

diff --git a/include/linux/mm.h b/include/linux/mm.h
index 48268d2d0282..4f9b2007efad 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -798,7 +798,9 @@ static inline int is_vmalloc_or_module_addr(const void *x)
 }
 #endif
 
-extern void *kvmalloc_node(size_t size, gfp_t flags, int node);
+void *kvmalloc_node_caller(size_t size, gfp_t flags, int node,
+		unsigned long caller);
+void *kvmalloc_node(size_t size, gfp_t flags, int node);
 static inline void *kvmalloc(size_t size, gfp_t flags)
 {
 	return kvmalloc_node(size, flags, NUMA_NO_NODE);
diff --git a/include/linux/slab.h b/include/linux/slab.h
index 0c97d788762c..6611b8ee55ee 100644
--- a/include/linux/slab.h
+++ b/include/linux/slab.h
@@ -663,6 +663,8 @@ extern void *__kmalloc_node_track_caller(size_t, gfp_t, int, unsigned long);
 
 #else /* CONFIG_NUMA */
 
+#define __kmalloc_node_track_caller(size, flags, node, caller) \
+	__kmalloc_track_caller(size, flags, caller)
 #define kmalloc_node_track_caller(size, flags, node) \
 	kmalloc_track_caller(size, flags)
 
diff --git a/mm/util.c b/mm/util.c
index a8bf17f18a81..ee4422be86a2 100644
--- a/mm/util.c
+++ b/mm/util.c
@@ -539,26 +539,8 @@ unsigned long vm_mmap(struct file *file, unsigned long addr,
 }
 EXPORT_SYMBOL(vm_mmap);
 
-/**
- * kvmalloc_node - attempt to allocate physically contiguous memory, but upon
- * failure, fall back to non-contiguous (vmalloc) allocation.
- * @size: size of the request.
- * @flags: gfp mask for the allocation - must be compatible (superset) with GFP_KERNEL.
- * @node: numa node to allocate from
- *
- * Uses kmalloc to get the memory but if the allocation fails then falls back
- * to the vmalloc allocator. Use kvfree for freeing the memory.
- *
- * Reclaim modifiers - __GFP_NORETRY and __GFP_NOFAIL are not supported.
- * __GFP_RETRY_MAYFAIL is supported, and it should be used only if kmalloc is
- * preferable to the vmalloc fallback, due to visible performance drawbacks.
- *
- * Please note that any use of gfp flags outside of GFP_KERNEL is careful to not
- * fall back to vmalloc.
- *
- * Return: pointer to the allocated memory of %NULL in case of failure
- */
-void *kvmalloc_node(size_t size, gfp_t flags, int node)
+void *kvmalloc_node_caller(size_t size, gfp_t flags, int node,
+		unsigned long caller)
 {
 	gfp_t kmalloc_flags = flags;
 	void *ret;
@@ -584,7 +566,7 @@ void *kvmalloc_node(size_t size, gfp_t flags, int node)
 			kmalloc_flags |= __GFP_NORETRY;
 	}
 
-	ret = kmalloc_node(size, kmalloc_flags, node);
+	ret = __kmalloc_node_track_caller(size, kmalloc_flags, node, caller);
 
 	/*
 	 * It doesn't really make sense to fallback to vmalloc for sub page
@@ -593,8 +575,31 @@ void *kvmalloc_node(size_t size, gfp_t flags, int node)
 	if (ret || size <= PAGE_SIZE)
 		return ret;
 
-	return __vmalloc_node(size, 1, flags, node,
-			__builtin_return_address(0));
+	return __vmalloc_node(size, 1, flags, node, (void *)caller);
+}
+
+/**
+ * kvmalloc_node - Allocate memory from a particular NUMA node.
+ * @size: Number of bytes to allocate.
+ * @flags: Memory allocation (GFP) flags.
+ * @node: NUMA node to allocate from.
+ *
+ * The allocated memory may or may not be physically contiguous, and so
+ * is not suitable for DMA.  Use kvfree() to free the memory.
+ *
+ * Reclaim modifiers - __GFP_NORETRY and __GFP_NOFAIL are not supported.
+ * __GFP_RETRY_MAYFAIL is supported, and it should be used only if kmalloc is
+ * preferable to the vmalloc fallback, due to visible performance drawbacks.
+ *
+ * Any use of gfp flags outside of GFP_KERNEL is careful to not
+ * fall back to vmalloc.
+ *
+ * Return: pointer to the allocated memory or %NULL in case of failure.
+ * %ZERO_SIZE_PTR if @size is zero.
+ */
+void *kvmalloc_node(size_t size, gfp_t flags, int node)
+{
+	return kvmalloc_node_caller(size, flags, node, _RET_IP_);
 }
 EXPORT_SYMBOL(kvmalloc_node);
 
-- 
2.30.2



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