Thread (10 messages) flat view 10 messages, 4 authors, 2009-09-02

Re: [PATCH] Fix fake numa on ppc

From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Date: 2009-09-02 05:53:07
Also in: lkml

On Tue, 2009-09-01 at 19:57 +0530, Balbir Singh wrote:
quoted
Heres the updated patch:

Signed-off-by: Ankita Garg <redacted> 
The thread is too messy. Please Ankita can you re-submit in proper
form (ie. subject, cset, signed-off & patch) please ?

In general, don't mix reply to comments and new patch submission,
or patchwork gets really confuse. Post a new name, with something
like [PATCH v2] <name of the patch> in the subject.

Thanks.

Cheers,
Ben.
quoted
Index: linux-2.6.31-rc5/arch/powerpc/mm/numa.c
===================================================================
--- linux-2.6.31-rc5.orig/arch/powerpc/mm/numa.c
+++ linux-2.6.31-rc5/arch/powerpc/mm/numa.c
@@ -26,6 +26,13 @@
 #include <asm/smp.h>

 static int numa_enabled = 1;
+static int fake_enabled = 1;
+
+/*
+ * The array maps a real numa node to the first fake node that gets
+ * created on it
+ */
+int fake_numa_node_mapping[MAX_NUMNODES];

 static char *cmdline __initdata;
@@ -49,14 +56,29 @@ static int __cpuinit fake_numa_create_ne
 	unsigned long long mem;
 	char *p = cmdline;
 	static unsigned int fake_nid;
+	static unsigned int prev_nid = 0;
 	static unsigned long long curr_boundary;

 	/*
 	 * Modify node id, iff we started creating NUMA nodes
 	 * We want to continue from where we left of the last time
 	 */
-	if (fake_nid)
+	if (fake_nid) {
+		/*
+		 * Moved over to the next real numa node, increment fake
+		 * node number and store the mapping of the real node to
+		 * the fake node
+		 */
+		if (prev_nid != *nid) {
+			fake_nid++;
+			fake_numa_node_mapping[*nid] = fake_nid;
+			prev_nid = *nid;
+			*nid = fake_nid;
+			return 0;
+		}
 		*nid = fake_nid;
+	}
+
 	/*
 	 * In case there are no more arguments to parse, the
 	 * node_id should be the same as the last fake node id
@@ -440,7 +462,7 @@ static int of_drconf_to_nid_single(struc
  */
 static int __cpuinit numa_setup_cpu(unsigned long lcpu)
 {
-	int nid = 0;
+	int nid = 0, new_nid;
 	struct device_node *cpu = of_get_cpu_node(lcpu, NULL);

 	if (!cpu) {
@@ -450,8 +472,15 @@ static int __cpuinit numa_setup_cpu(unsi

 	nid = of_node_to_nid_single(cpu);

+	if (fake_enabled && nid) {
+		new_nid = fake_numa_node_mapping[nid];
+		if (new_nid > 0)
+			nid = new_nid;
+	}
+
 	if (nid < 0 || !node_online(nid))
 		nid = any_online_node(NODE_MASK_ALL);
+
 out:
 	map_cpu_to_node(lcpu, nid);
@@ -1005,8 +1034,12 @@ static int __init early_numa(char *p)
 		numa_debug = 1;

 	p = strstr(p, "fake=");
-	if (p)
+	if (p) {
 		cmdline = p + strlen("fake=");
+		if (numa_enabled) {
+			fake_enabled = 1;
+		}
+	}

 	return 0;
 }

Looks good to me


Reviewed-by: Balbir Singh <redacted>
 
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