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| author | Zhao Yakui <yakui.zhao@intel.com> | 2008-06-24 17:58:53 +0800 |
|---|---|---|
| committer | Andi Kleen <andi@basil.nowhere.org> | 2008-07-16 23:27:05 +0200 |
| commit | c1e3b377ad48febba6f91b8ae42c44ee4d4ab45e (patch) | |
| tree | 7893e4226f52c4001150066f544415c1b17741f5 /Documentation/kernel-parameters.txt | |
| parent | 5b53496a5ad79e91052f72761a7c5516b069bc99 (diff) | |
| download | lwn-c1e3b377ad48febba6f91b8ae42c44ee4d4ab45e.tar.gz lwn-c1e3b377ad48febba6f91b8ae42c44ee4d4ab45e.zip | |
ACPI: Create "idle=halt" bootparam
"idle=halt" limits the idle loop to using
the halt instruction. No MWAIT, no IO accesses,
no C-states deeper than C1.
If something is broken in the idle code,
"idle=halt" is a less severe workaround
than "idle=poll" which disables all power savings.
Signed-off-by: Zhao Yakui <yakui.zhao@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Diffstat (limited to 'Documentation/kernel-parameters.txt')
| -rw-r--r-- | Documentation/kernel-parameters.txt | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 312fe77764a4..65db7f4711aa 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -818,7 +818,7 @@ and is between 256 and 4096 characters. It is defined in the file See Documentation/ide/ide.txt. idle= [X86] - Format: idle=poll or idle=mwait + Format: idle=poll or idle=mwait, idle=halt Poll forces a polling idle loop that can slightly improves the performance of waking up a idle CPU, but will use a lot of power and make the system run hot. Not recommended. @@ -826,6 +826,8 @@ and is between 256 and 4096 characters. It is defined in the file to not use it because it doesn't save as much power as a normal idle loop use the MONITOR/MWAIT idle loop anyways. Performance should be the same as idle=poll. + idle=halt. Halt is forced to be used for CPU idle. + In such case C2/C3 won't be used again. ide-pci-generic.all-generic-ide [HW] (E)IDE subsystem Claim all unknown PCI IDE storage controllers. |