[PATCH 01/16] x86/oprofile: add module parameter option to force a core 2 cpu

Jeremy Fitzhardinge
2009-06-16T20:16:44Z

From: Robert Richter <robert.richter@amd.com>

The current userland does not yet fully support all cpu types
implemented in the kernel. With the module parameter:

oprofile.cpu_type=core_2

the kernel reports a core_2 cpu to the userland on an Intel system and
thus makes oprofile usable with current distros.

Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Robert Richter <robert.richter@amd.com>
---
Documentation/kernel-parameters.txt | 3 ++-
arch/x86/oprofile/nmi_int.c | 17 ++++++++++++++---
2 files changed, 16 insertions(+), 4 deletions(-)

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 6ce5f48..ea7ead3 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -1653,10 +1653,11 @@ and is between 256 and 4096 characters. It is defined in the file
oprofile.cpu_type= Force an oprofile cpu type
This might be useful if you have an older oprofile
userland or if you want common events.
- Format: { archperfmon }
+ Format: { archperfmon | core_2 }
archperfmon: [X86] Force use of architectural
perfmon on Intel CPUs instead of the
CPU specific event set.
+ core_2: [X86] On Intel systems: report core_2 CPU.

osst= [HW,SCSI] SCSI Tape Driver
Format: <buffer_size>,<write_threshold>
diff --git a/arch/x86/oprofile/nmi_int.c b/arch/x86/oprofile/nmi_int.c
index 3b285e6..d7348a2 100644
--- a/arch/x86/oprofile/nmi_int.c
+++ b/arch/x86/oprofile/nmi_int.c
@@ -386,12 +386,20 @@ static int __init p4_init(char **cpu_type)
return 0;
}

-static int force_arch_perfmon;
+static enum {
+ NONE = 0,
+ ARCH_PERFMON,
+ CORE_2,
+} forced_cpu;
+
static int force_cpu_type(const char *str, struct kernel_param *kp)
{
if (!strcmp(str, "archperfmon")) {
- force_arch_perfmon = 1;
+ forced_cpu = ARCH_PERFMON;
printk(KERN_INFO "oprofile: forcing architectural perfmon\n");
+ } else if (!strcmp(str, "core_2")) {
+ forced_cpu = CORE_2;
+ printk(KERN_INFO "oprofile: forcing core_2\n");
}

return 0;
@@ -402,9 +410,12 @@ static int __init ppro_init(char **cpu_type)
{
__u8 cpu_model = boot_cpu_data.x86_model;

- if (force_arch_perfmon && cpu_has_arch_perfmon)
+ if (forced_cpu == ARCH_PERFMON && cpu_has_arch_perfmon)
return 0;

+ if (forced_cpu == CORE_2)
+ cpu_model = 15;
+
switch (cpu_model) {
case 0 ... 2:
*cpu_type = "i386/ppro";
--
1.6.2.2