[PATCH] Allow an arch to expand node boundaries
Arch-independent zone-sizing determines the size of a node
(pgdat->node_spanned_pages) based on the physical memory that was
registered by the architecture. However, when
CONFIG_MEMORY_HOTPLUG_RESERVE is set, the architecture expects that the
spanned_pages will be much larger and that mem_map will be allocated that
is used lated on memory hot-add.
This patch allows an architecture that sets CONFIG_MEMORY_HOTPLUG_RESERVE
to call push_node_boundaries() which will set the node beginning and end to
at *least* the requested boundary.
Cc: Dave Hansen <haveblue@us.ibm.com>
Cc: Andy Whitcroft <apw@shadowen.org>
Cc: Andi Kleen <ak@muc.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: "Keith Mannthey" <kmannth@gmail.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Yasunori Goto <y-goto@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 75133e1..acbf58f 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -131,6 +131,10 @@
int __initdata nr_nodemap_entries;
unsigned long __initdata arch_zone_lowest_possible_pfn[MAX_NR_ZONES];
unsigned long __initdata arch_zone_highest_possible_pfn[MAX_NR_ZONES];
+#ifdef CONFIG_MEMORY_HOTPLUG_RESERVE
+ unsigned long __initdata node_boundary_start_pfn[MAX_NUMNODES];
+ unsigned long __initdata node_boundary_end_pfn[MAX_NUMNODES];
+#endif /* CONFIG_MEMORY_HOTPLUG_RESERVE */
#endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
#ifdef CONFIG_DEBUG_VM
@@ -2095,6 +2099,62 @@
}
/**
+ * push_node_boundaries - Push node boundaries to at least the requested boundary
+ * @nid: The nid of the node to push the boundary for
+ * @start_pfn: The start pfn of the node
+ * @end_pfn: The end pfn of the node
+ *
+ * In reserve-based hot-add, mem_map is allocated that is unused until hotadd
+ * time. Specifically, on x86_64, SRAT will report ranges that can potentially
+ * be hotplugged even though no physical memory exists. This function allows
+ * an arch to push out the node boundaries so mem_map is allocated that can
+ * be used later.
+ */
+#ifdef CONFIG_MEMORY_HOTPLUG_RESERVE
+void __init push_node_boundaries(unsigned int nid,
+ unsigned long start_pfn, unsigned long end_pfn)
+{
+ printk(KERN_DEBUG "Entering push_node_boundaries(%u, %lu, %lu)\n",
+ nid, start_pfn, end_pfn);
+
+ /* Initialise the boundary for this node if necessary */
+ if (node_boundary_end_pfn[nid] == 0)
+ node_boundary_start_pfn[nid] = -1UL;
+
+ /* Update the boundaries */
+ if (node_boundary_start_pfn[nid] > start_pfn)
+ node_boundary_start_pfn[nid] = start_pfn;
+ if (node_boundary_end_pfn[nid] < end_pfn)
+ node_boundary_end_pfn[nid] = end_pfn;
+}
+
+/* If necessary, push the node boundary out for reserve hotadd */
+static void __init account_node_boundary(unsigned int nid,
+ unsigned long *start_pfn, unsigned long *end_pfn)
+{
+ printk(KERN_DEBUG "Entering account_node_boundary(%u, %lu, %lu)\n",
+ nid, *start_pfn, *end_pfn);
+
+ /* Return if boundary information has not been provided */
+ if (node_boundary_end_pfn[nid] == 0)
+ return;
+
+ /* Check the boundaries and update if necessary */
+ if (node_boundary_start_pfn[nid] < *start_pfn)
+ *start_pfn = node_boundary_start_pfn[nid];
+ if (node_boundary_end_pfn[nid] > *end_pfn)
+ *end_pfn = node_boundary_end_pfn[nid];
+}
+#else
+void __init push_node_boundaries(unsigned int nid,
+ unsigned long start_pfn, unsigned long end_pfn) {}
+
+static void __init account_node_boundary(unsigned int nid,
+ unsigned long *start_pfn, unsigned long *end_pfn) {}
+#endif
+
+
+/**
* get_pfn_range_for_nid - Return the start and end page frames for a node
* @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned
* @start_pfn: Passed by reference. On return, it will have the node start_pfn
@@ -2121,6 +2181,9 @@
printk(KERN_WARNING "Node %u active with no memory\n", nid);
*start_pfn = 0;
}
+
+ /* Push the node boundaries out if requested */
+ account_node_boundary(nid, start_pfn, end_pfn);
}
/*
@@ -2527,6 +2590,10 @@
{
memset(early_node_map, 0, sizeof(early_node_map));
nr_nodemap_entries = 0;
+#ifdef CONFIG_MEMORY_HOTPLUG_RESERVE
+ memset(node_boundary_start_pfn, 0, sizeof(node_boundary_start_pfn));
+ memset(node_boundary_end_pfn, 0, sizeof(node_boundary_end_pfn));
+#endif /* CONFIG_MEMORY_HOTPLUG_RESERVE */
}
/* Compare two active node_active_regions */