diff options
author | Len Brown <len.brown@intel.com> | 2013-02-02 01:31:56 -0500 |
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committer | Len Brown <len.brown@intel.com> | 2013-02-13 18:22:08 -0500 |
commit | 32e9518005c8dd9ed668f40f98632c8186df4909 (patch) | |
tree | 277dde14dec62b8734d404f74f55335ce354d43f /drivers/idle | |
parent | e022e7eb90f3edb83f9ff77825eda3d1b3a2f2e0 (diff) | |
download | linux-32e9518005c8dd9ed668f40f98632c8186df4909.tar.bz2 |
intel_idle: export both C1 and C1E
Here we disable HW promotion of C1 to C1E
and export both C1 and C1E and distinct C-states.
This allows a cpuidle governor to choose a lower latency
C-state than C1E when necessary to satisfy performance
and QOS constraints -- and still save power versus polling.
This also corrects the erroneous latency previously reported
for C1E -- it is 10usec, not 1usec.
Note that if you use "intel_idle.max_cstate=N",
then you must increment N by 1 to get the same behavior
after this change.
Signed-off-by: Len Brown <len.brown@intel.com>
Diffstat (limited to 'drivers/idle')
-rw-r--r-- | drivers/idle/intel_idle.c | 54 |
1 files changed, 49 insertions, 5 deletions
diff --git a/drivers/idle/intel_idle.c b/drivers/idle/intel_idle.c index 927cfb4d66f4..5d6675013864 100644 --- a/drivers/idle/intel_idle.c +++ b/drivers/idle/intel_idle.c @@ -90,6 +90,7 @@ struct idle_cpu { * Indicate which enable bits to clear here. */ unsigned long auto_demotion_disable_flags; + bool disable_promotion_to_c1e; }; static const struct idle_cpu *icpu; @@ -132,6 +133,13 @@ static struct cpuidle_state nehalem_cstates[CPUIDLE_STATE_MAX] = { .target_residency = 6, .enter = &intel_idle }, { + .name = "C1E-NHM", + .desc = "MWAIT 0x01", + .flags = MWAIT2flg(0x01) | CPUIDLE_FLAG_TIME_VALID, + .exit_latency = 10, + .target_residency = 20, + .enter = &intel_idle }, + { .name = "C3-NHM", .desc = "MWAIT 0x10", .flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_TLB_FLUSHED, @@ -154,8 +162,15 @@ static struct cpuidle_state snb_cstates[CPUIDLE_STATE_MAX] = { .name = "C1-SNB", .desc = "MWAIT 0x00", .flags = MWAIT2flg(0x00) | CPUIDLE_FLAG_TIME_VALID, - .exit_latency = 1, - .target_residency = 1, + .exit_latency = 2, + .target_residency = 2, + .enter = &intel_idle }, + { + .name = "C1E-SNB", + .desc = "MWAIT 0x01", + .flags = MWAIT2flg(0x01) | CPUIDLE_FLAG_TIME_VALID, + .exit_latency = 10, + .target_residency = 20, .enter = &intel_idle }, { .name = "C3-SNB", @@ -191,6 +206,13 @@ static struct cpuidle_state ivb_cstates[CPUIDLE_STATE_MAX] = { .target_residency = 1, .enter = &intel_idle }, { + .name = "C1E-IVB", + .desc = "MWAIT 0x01", + .flags = MWAIT2flg(0x01) | CPUIDLE_FLAG_TIME_VALID, + .exit_latency = 10, + .target_residency = 20, + .enter = &intel_idle }, + { .name = "C3-IVB", .desc = "MWAIT 0x10", .flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_TLB_FLUSHED, @@ -224,6 +246,13 @@ static struct cpuidle_state hsw_cstates[CPUIDLE_STATE_MAX] = { .target_residency = 2, .enter = &intel_idle }, { + .name = "C1E-HSW", + .desc = "MWAIT 0x01", + .flags = MWAIT2flg(0x01) | CPUIDLE_FLAG_TIME_VALID, + .exit_latency = 10, + .target_residency = 20, + .enter = &intel_idle }, + { .name = "C3-HSW", .desc = "MWAIT 0x10", .flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_TLB_FLUSHED, @@ -250,11 +279,11 @@ static struct cpuidle_state hsw_cstates[CPUIDLE_STATE_MAX] = { static struct cpuidle_state atom_cstates[CPUIDLE_STATE_MAX] = { { - .name = "C1-ATM", + .name = "C1E-ATM", .desc = "MWAIT 0x00", .flags = MWAIT2flg(0x00) | CPUIDLE_FLAG_TIME_VALID, - .exit_latency = 1, - .target_residency = 4, + .exit_latency = 10, + .target_residency = 20, .enter = &intel_idle }, { .name = "C2-ATM", @@ -377,10 +406,19 @@ static void auto_demotion_disable(void *dummy) msr_bits &= ~(icpu->auto_demotion_disable_flags); wrmsrl(MSR_NHM_SNB_PKG_CST_CFG_CTL, msr_bits); } +static void c1e_promotion_disable(void *dummy) +{ + unsigned long long msr_bits; + + rdmsrl(MSR_IA32_POWER_CTL, msr_bits); + msr_bits &= ~0x2; + wrmsrl(MSR_IA32_POWER_CTL, msr_bits); +} static const struct idle_cpu idle_cpu_nehalem = { .state_table = nehalem_cstates, .auto_demotion_disable_flags = NHM_C1_AUTO_DEMOTE | NHM_C3_AUTO_DEMOTE, + .disable_promotion_to_c1e = true, }; static const struct idle_cpu idle_cpu_atom = { @@ -394,14 +432,17 @@ static const struct idle_cpu idle_cpu_lincroft = { static const struct idle_cpu idle_cpu_snb = { .state_table = snb_cstates, + .disable_promotion_to_c1e = true, }; static const struct idle_cpu idle_cpu_ivb = { .state_table = ivb_cstates, + .disable_promotion_to_c1e = true, }; static const struct idle_cpu idle_cpu_hsw = { .state_table = hsw_cstates, + .disable_promotion_to_c1e = true, }; #define ICPU(model, cpu) \ @@ -544,6 +585,9 @@ static int intel_idle_cpuidle_driver_init(void) if (icpu->auto_demotion_disable_flags) on_each_cpu(auto_demotion_disable, NULL, 1); + if (icpu->disable_promotion_to_c1e) /* each-cpu is redundant */ + on_each_cpu(c1e_promotion_disable, NULL, 1); + return 0; } |