From c1e3b377ad48febba6f91b8ae42c44ee4d4ab45e Mon Sep 17 00:00:00 2001 From: Zhao Yakui Date: Tue, 24 Jun 2008 17:58:53 +0800 Subject: 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 Signed-off-by: Len Brown Signed-off-by: Andi Kleen --- Documentation/kernel-parameters.txt | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'Documentation') diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 312fe77764a..65db7f4711a 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. -- cgit v1.2.3-70-g09d2