Re: [patch 2/2] x86, numa: Fix cpu nodemasks for NUMA emulation and CONFIG_DEBUG_PER_CPU_MAPS

From: KOSAKI Motohiro
Date: Thu Apr 21 2011 - 01:46:05 EST


> cpu nodemasks under CONFIG_DEBUG_PER_CPU_MAPS when NUMA emulation is
> enabled is currently broken because it does not iterate through every
> emulated node and bind cpus that have affinity to it. NUMA emulation
> should bind each cpu to every local node to accurately represent the true
> NUMA topology of the underlying machine.
>
> debug_cpumask_set_cpu() needs to be fixed at the same time so that the
> debugging information that it emits shows the new cpumask of the node
> being assigned when the cpu is being added or removed. It can now take
> responsibility of setting or clearing the cpu itself to remove the need
> for duplicate code.
>
> Also changes its last formal, "enable", to have the correct bool type
> since it can only be true or false.
>
> Signed-off-by: David Rientjes <rientjes@xxxxxxxxxx>

Ok, this is better. I haven't realized node_to_cpumask_map[] don't
need exclusive cpu map.

Thank you!


Tested-by: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>



However

> -struct cpumask __cpuinit *debug_cpumask_set_cpu(int cpu, int enable)
> +void debug_cpumask_set_cpu(int cpu, int node, bool enable)
> {
> - int node = early_cpu_to_node(cpu);
> struct cpumask *mask;
> char buf[64];
>
> @@ -227,9 +226,14 @@ struct cpumask __cpuinit *debug_cpumask_set_cpu(int cpu, int enable)
> if (!mask) {
> pr_err("node_to_cpumask_map[%i] NULL\n", node);
> dump_stack();
> - return NULL;
> + return;
> }
>
> + if (enable)
> + cpumask_set_cpu(cpu, mask);
> + else
> + cpumask_clear_cpu(cpu, mask);
> +

Following patch also shold be apply?


From aaca24826696f7911bd66380baa18cfbe4f4b18e Mon Sep 17 00:00:00 2001
From: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>
Date: Thu, 21 Apr 2011 14:01:42 +0900
Subject: [PATCH] Fix

debug_cpumask_set_cpu() has tree return statement. we have change
rest two return statement.

Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>
---
arch/x86/mm/numa.c | 4 ++--
1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/mm/numa.c b/arch/x86/mm/numa.c
index 0471b1d6..745258d 100644
--- a/arch/x86/mm/numa.c
+++ b/arch/x86/mm/numa.c
@@ -220,7 +220,7 @@ void debug_cpumask_set_cpu(int cpu, int node, bool enable)

if (node == NUMA_NO_NODE) {
/* early_cpu_to_node() already emits a warning and trace */
- return NULL;
+ return;
}
mask = node_to_cpumask_map[node];
if (!mask) {
@@ -238,7 +238,7 @@ void debug_cpumask_set_cpu(int cpu, int node, bool enable)
printk(KERN_DEBUG "%s cpu %d node %d: mask now %s\n",
enable ? "numa_add_cpu" : "numa_remove_cpu",
cpu, node, buf);
- return mask;
+ return;
}

# ifndef CONFIG_NUMA_EMU
--
1.7.3.1




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