Re: [Perfctr-devel] 2.6.19-rc6-git10 new perfmon code base + libpfm + pfmon

[Ralf Baechle <ralf@linux-mips.org>]

On Tue, Nov 28, 2006 at 08:05:02PM +0100, Philip J. Mucci wrote:

> Forgive me, I thought Stefane had posted the announcement of the new
> perfmon kernel substrate on Linux/MIPS list. I see now that he did not,
> so it's likely that the below patch has little meaning to you folks. I
> do know however, that there are some broadcom folks tracking this work.
> 
> This is not meant to be a patch for the Linux/MIPS tree, but rather the
> perfmon2 patch when applied to Linus' latest GIT tree. This hack (marked
> as such) gets around a NULL pointer dereference upon boot. I make no
> claims other than that it lets the MIPS folks play with the perfmon2
> implementation.

So following our private mail exchange I've checked in below fix.

  Ralf

commit 83eee867cf914c968933e8bc3acf7a3fe58ceaed
Author: Ralf Baechle <ralf@linux-mips.org>
Date:   Wed Nov 29 15:04:08 2006 +0000

[MIPS] Do topology_init even on uniprocessor kernels.

Otherwise CPU 0 doesn't show up in sysfs which breaks some software.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

diff --git a/arch/mips/kernel/Makefile b/arch/mips/kernel/Makefile
index cd9cec9..6bfbbed 100644
--- a/arch/mips/kernel/Makefile
+++ b/arch/mips/kernel/Makefile
@@ -6,7 +6,7 @@ extra-y         := head.o init_task.o vmlinux.l
 
 obj-y          += cpu-probe.o branch.o entry.o genex.o irq.o process.o \
                   ptrace.o reset.o semaphore.o setup.o signal.o syscall.o \
-                  time.o traps.o unaligned.o
+                  time.o topology.o traps.o unaligned.o
 
 binfmt_irix-objs       := irixelf.o irixinv.o irixioctl.o irixsig.o    \
                           irix5sys.o sysirix.o
diff --git a/arch/mips/kernel/smp.c b/arch/mips/kernel/smp.c
index db80957..49db516 100644
--- a/arch/mips/kernel/smp.c
+++ b/arch/mips/kernel/smp.c
@@ -463,28 +463,5 @@ void flush_tlb_one(unsigned long vaddr)
        smp_on_each_tlb(flush_tlb_one_ipi, (void *) vaddr);
 }
 
-static DEFINE_PER_CPU(struct cpu, cpu_devices);
-
-static int __init topology_init(void)
-{
-       int i, ret;
-
-#ifdef CONFIG_NUMA
-       for_each_online_node(i)
-               register_one_node(i);
-#endif /* CONFIG_NUMA */
-
-       for_each_present_cpu(i) {
-               ret = register_cpu(&per_cpu(cpu_devices, i), i);
-               if (ret)
-                       printk(KERN_WARNING "topology_init: register_cpu %d "
-                              "failed (%d)\n", i, ret);
-       }
-
-       return 0;
-}
-
-subsys_initcall(topology_init);
-
 EXPORT_SYMBOL(flush_tlb_page);
 EXPORT_SYMBOL(flush_tlb_one);
diff --git a/arch/mips/kernel/topology.c b/arch/mips/kernel/topology.c
new file mode 100644
index 0000000..660e44e
--- /dev/null
+++ b/arch/mips/kernel/topology.c
@@ -0,0 +1,29 @@
+#include <linux/cpu.h>
+#include <linux/cpumask.h>
+#include <linux/init.h>
+#include <linux/node.h>
+#include <linux/nodemask.h>
+#include <linux/percpu.h>
+
+static DEFINE_PER_CPU(struct cpu, cpu_devices);
+
+static int __init topology_init(void)
+{
+       int i, ret;
+
+#ifdef CONFIG_NUMA
+       for_each_online_node(i)
+               register_one_node(i);
+#endif /* CONFIG_NUMA */
+
+       for_each_present_cpu(i) {
+               ret = register_cpu(&per_cpu(cpu_devices, i), i);
+               if (ret)
+                       printk(KERN_WARNING "topology_init: register_cpu %d "
+                              "failed (%d)\n", i, ret);
+       }
+
+       return 0;
+}
+
+subsys_initcall(topology_init);