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author | njl <njl@FreeBSD.org> | 2004-05-07 05:22:38 +0000 |
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committer | njl <njl@FreeBSD.org> | 2004-05-07 05:22:38 +0000 |
commit | 055815ed7e46944882d8d61591fbbd5d1e390a84 (patch) | |
tree | 9006c91f89da2e5720d976ecff27f6610c16d209 /share | |
parent | f822beb73630f72486689173c8a0ef9670e15c56 (diff) | |
download | FreeBSD-src-055815ed7e46944882d8d61591fbbd5d1e390a84.zip FreeBSD-src-055815ed7e46944882d8d61591fbbd5d1e390a84.tar.gz |
Change hw.acpi.cpu.cx_lowest to accept values in the form of C1,
C2, ... Update power_profile to use the new format. Update the
man page to reflect this and give more info on Cx states.
Diffstat (limited to 'share')
-rw-r--r-- | share/man/man4/acpi.4 | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/share/man/man4/acpi.4 b/share/man/man4/acpi.4 index 0a16d70..8f47880 100644 --- a/share/man/man4/acpi.4 +++ b/share/man/man4/acpi.4 @@ -366,19 +366,21 @@ The counters are reset when .Va hw.acpi.cpu.cx_lowest is modified. .It Va hw.acpi.cpu.cx_lowest -Zero-based index of the lowest CPU idle state to use. -A scheduling algorithm will select between 0...index for the state -to use during the next sleep. +Lowest Cx state to use for idling the CPU. +A scheduling algorithm will select states between C1 and this setting +as system load dictates. To enable ACPI CPU idling control, .Va machdep.cpu_idle_hlt must be set to 1. .It Va hw.acpi.cpu.cx_supported List of supported CPU idle states and their transition latency in microseconds. -Each state has a type, C1-3. +Each state has a type (e.g., C2.) C1 is equivalent to the ia32 HLT instruction, C2 provides a deeper sleep with the same semantics, and C3 provides the deepest sleep but additionally requires bus mastering to be disabled. +States greater than C3 provide even more power savings with the same +semantics as the C3 state. Deeper sleeps provide more power savings but increased transition latency when an interrupt occurs. .El |