diff options
| author | Len Brown <len.brown@intel.com> | 2011-01-18 20:48:27 -0500 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2011-03-27 12:00:13 -0700 |
| commit | cca24e5f3fa80fc5043bae978aa26d8ffd1d7402 (patch) | |
| tree | 9b0f283bbadd2a9f86f64004ddb853ed5fab7c85 /arch | |
| parent | 698c1ea2cde52b8d59c4427eb768abf721e7a5b9 (diff) | |
intel_idle: disable NHM/WSM HW C-state auto-demotion
commit 14796fca2bd22acc73dd0887248d003b0f441d08 upstream.
Hardware C-state auto-demotion is a mechanism where the HW overrides
the OS C-state request, instead demoting to a shallower state,
which is less expensive, but saves less power.
Modern Linux should generally get exactly the states it requests.
In particular, when a CPU is taken off-line, it must not be demoted, else
it can prevent the entire package from reaching deep C-states.
https://bugzilla.kernel.org/show_bug.cgi?id=25252
Signed-off-by: Len Brown <len.brown@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/include/asm/msr-index.h | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h index 6b89f5e86021..05c302c697c3 100644 --- a/arch/x86/include/asm/msr-index.h +++ b/arch/x86/include/asm/msr-index.h @@ -36,6 +36,10 @@ #define MSR_IA32_PERFCTR1 0x000000c2 #define MSR_FSB_FREQ 0x000000cd +#define MSR_NHM_SNB_PKG_CST_CFG_CTL 0x000000e2 +#define NHM_C3_AUTO_DEMOTE (1UL << 25) +#define NHM_C1_AUTO_DEMOTE (1UL << 26) + #define MSR_MTRRcap 0x000000fe #define MSR_IA32_BBL_CR_CTL 0x00000119 |