From 1dcdb5a9e7c235e6e80f1f4d5b8247b3e5347e48 Mon Sep 17 00:00:00 2001 From: Andi Kleen Date: Mon, 27 Apr 2009 17:44:11 +0200 Subject: [PATCH] oprofile: re-add force_arch_perfmon option This re-adds the force_arch_perfmon option that was in the original arch perfmon patchkit. Originally this was rejected in favour of a generalized perfmon=name option, but it turned out implementing the later in a reliable way is hard (and it would have been easy to crash the kernel if a user gets it wrong) But now Atom and Core i7 support being readded a user would need to update their oprofile userland to beyond 0.9.4 to use oprofile again on Atom or Core i7. To avoid this problem readd the force_arch_perfmon option. Signed-off-by: Andi Kleen Signed-off-by: Robert Richter --- Documentation/kernel-parameters.txt | 6 ++++++ arch/x86/oprofile/nmi_int.c | 6 ++++++ 2 files changed, 12 insertions(+) diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 90b3924071b..9b9566bf330 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -1650,6 +1650,12 @@ and is between 256 and 4096 characters. It is defined in the file oprofile.timer= [HW] Use timer interrupt instead of performance counters + oprofile.force_arch_perfmon=1 [X86] + Force use of architectural perfmon instead of + the CPU specific event set. + This might be useful if you have older oprofile + userland or if you want common events over Intel CPUs. + osst= [HW,SCSI] SCSI Tape Driver Format: , See also Documentation/scsi/st.txt. diff --git a/arch/x86/oprofile/nmi_int.c b/arch/x86/oprofile/nmi_int.c index 202864ad49a..e5171c99e15 100644 --- a/arch/x86/oprofile/nmi_int.c +++ b/arch/x86/oprofile/nmi_int.c @@ -389,10 +389,16 @@ static int __init p4_init(char **cpu_type) return 0; } +int force_arch_perfmon; +module_param(force_arch_perfmon, int, 0); + static int __init ppro_init(char **cpu_type) { __u8 cpu_model = boot_cpu_data.x86_model; + if (force_arch_perfmon && cpu_has_arch_perfmon) + return 0; + switch (cpu_model) { case 0 ... 2: *cpu_type = "i386/ppro";