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| author | Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> | 2012-03-13 20:06:57 -0400 |
|---|---|---|
| committer | Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> | 2012-03-20 15:31:38 -0400 |
| commit | 48cdd8287f47a3cdad5b9273a5ef81bf605f7826 (patch) | |
| tree | 54fe14de42d138d232af36d4374d49fa4ef8dd10 /arch/x86 | |
| parent | 448c8b1d07d5342922567e138a4b0108a42c24fb (diff) | |
| download | linux-rt-48cdd8287f47a3cdad5b9273a5ef81bf605f7826.tar.gz | |
xen/cpufreq: Disable the cpu frequency scaling drivers from loading.
By using the functionality provided by "[CPUFREQ]: provide
disable_cpuidle() function to disable the API."
Under the Xen hypervisor we do not want the initial domain to exercise
the cpufreq scaling drivers. This is b/c the Xen hypervisor is
in charge of doing this as well and we can end up with both the
Linux kernel and the hypervisor trying to change the P-states
leading to weird performance issues.
Acked-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
[v2: Fix compile error spotted by Benjamin Schweikert <b.schweikert@googlemail.com>]
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/xen/setup.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c index 12366238d07d..1ba8dff26753 100644 --- a/arch/x86/xen/setup.c +++ b/arch/x86/xen/setup.c @@ -10,6 +10,7 @@ #include <linux/pm.h> #include <linux/memblock.h> #include <linux/cpuidle.h> +#include <linux/cpufreq.h> #include <asm/elf.h> #include <asm/vdso.h> @@ -420,6 +421,7 @@ void __init xen_arch_setup(void) boot_cpu_data.hlt_works_ok = 1; #endif disable_cpuidle(); + disable_cpufreq(); WARN_ON(set_pm_idle_to_default()); fiddle_vdso(); } |