---

yaml
---
r: 137075
b: refs/heads/master
c: 9a4f8a8
h: refs/heads/master
i:
  137073: 52ac06b
  137071: 9921244
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: cafe8816b217b98dc3f268d3b77445da498beb4f
+refs/heads/master: 9a4f8a878b68d5a5d9ee60908a52cf6a55e1b823

trunk/arch/x86/kernel/setup_percpu.c

@@ -241,24 +241,31 @@ static ssize_t __init setup_pcpu_remap(size_t static_size)
  * Embedding allocator
  *
  * The first chunk is sized to just contain the static area plus
- * PERCPU_DYNAMIC_RESERVE and allocated as a contiguous area using
- * bootmem allocator and used as-is without being mapped into vmalloc
- * area.  This enables the first chunk to piggy back on the linear
- * physical PMD mapping and doesn't add any additional pressure to
- * TLB.
+ * module and dynamic reserves, and allocated as a contiguous area
+ * using bootmem allocator and used as-is without being mapped into
+ * vmalloc area.  This enables the first chunk to piggy back on the
+ * linear physical PMD mapping and doesn't add any additional pressure
+ * to TLB.  Note that if the needed size is smaller than the minimum
+ * unit size, the leftover is returned to the bootmem allocator.
  */
 static void *pcpue_ptr __initdata;
+static size_t pcpue_size __initdata;
 static size_t pcpue_unit_size __initdata;
 
 static struct page * __init pcpue_get_page(unsigned int cpu, int pageno)
 {
-	return virt_to_page(pcpue_ptr + cpu * pcpue_unit_size
-			    + ((size_t)pageno << PAGE_SHIFT));
+	size_t off = (size_t)pageno << PAGE_SHIFT;
+
+	if (off >= pcpue_size)
+		return NULL;
+
+	return virt_to_page(pcpue_ptr + cpu * pcpue_unit_size + off);
 }
 
 static ssize_t __init setup_pcpu_embed(size_t static_size)
 {
 	unsigned int cpu;
+	size_t dyn_size;
 
 	/*
 	 * If large page isn't supported, there's no benefit in doing
@@ -269,25 +276,30 @@ static ssize_t __init setup_pcpu_embed(size_t static_size)
 		return -EINVAL;
 
 	/* allocate and copy */
-	pcpue_unit_size = PFN_ALIGN(static_size + PERCPU_DYNAMIC_RESERVE);
-	pcpue_unit_size = max_t(size_t, pcpue_unit_size, PCPU_MIN_UNIT_SIZE);
+	pcpue_size = PFN_ALIGN(static_size + PERCPU_DYNAMIC_RESERVE);
+	pcpue_unit_size = max_t(size_t, pcpue_size, PCPU_MIN_UNIT_SIZE);
+	dyn_size = pcpue_size - static_size;
+
 	pcpue_ptr = pcpu_alloc_bootmem(0, num_possible_cpus() * pcpue_unit_size,
 				       PAGE_SIZE);
 	if (!pcpue_ptr)
 		return -ENOMEM;
 
-	for_each_possible_cpu(cpu)
-		memcpy(pcpue_ptr + cpu * pcpue_unit_size, __per_cpu_load,
-		       static_size);
+	for_each_possible_cpu(cpu) {
+		void *ptr = pcpue_ptr + cpu * pcpue_unit_size;
+
+		free_bootmem(__pa(ptr + pcpue_size),
+			     pcpue_unit_size - pcpue_size);
+		memcpy(ptr, __per_cpu_load, static_size);
+	}
 
 	/* we're ready, commit */
 	pr_info("PERCPU: Embedded %zu pages at %p, static data %zu bytes\n",
-		pcpue_unit_size >> PAGE_SHIFT, pcpue_ptr, static_size);
+		pcpue_size >> PAGE_SHIFT, pcpue_ptr, static_size);
 
 	return pcpu_setup_first_chunk(pcpue_get_page, static_size,
-				      pcpue_unit_size,
-				      pcpue_unit_size - static_size, pcpue_ptr,
-				      NULL);
+				      pcpue_unit_size, dyn_size,
+				      pcpue_ptr, NULL);
 }
 
 /*