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authorLen Brown <len.brown@intel.com>2011-04-01 15:46:09 -0400
committerLen Brown <len.brown@intel.com>2011-05-29 03:39:17 -0400
commit5d4c47e0195b989f284907358bd5c268a44b91c7 (patch)
tree3a7c81ff3b3f5a5eb6199044a72c0145b58db413 /arch/x86
parentcdaab4a0d330f70c0e5ad8c3f7c65c2e375ea180 (diff)
x86 idle: deprecate mwait_idle() and "idle=mwait" cmdline param
mwait_idle() is a C1-only idle loop intended to be more efficient than HLT on SMP hardware that supports it. But mwait_idle() has been replaced by the more general mwait_idle_with_hints(), which handles both C1 and deeper C-states. ACPI uses only mwait_idle_with_hints(), and never uses mwait_idle(). Deprecate mwait_idle() and the "idle=mwait" cmdline param to simplify the x86 idle code. After this change, kernels configured with (!CONFIG_ACPI=n && !CONFIG_INTEL_IDLE=n) when run on hardware that support MWAIT will simply use HLT. If MWAIT is desired on those systems, cpuidle and the cpuidle drivers above can be used. cc: x86@kernel.org cc: stable@kernel.org # .39.x Signed-off-by: Len Brown <len.brown@intel.com>
Diffstat (limited to 'arch/x86')
-rw-r--r--arch/x86/kernel/process.c1
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index 84f3cdae440..8fb182956cb 100644
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -645,6 +645,7 @@ static int __init idle_setup(char *str)
boot_option_idle_override = IDLE_POLL;
} else if (!strcmp(str, "mwait")) {
boot_option_idle_override = IDLE_FORCE_MWAIT;
+ WARN_ONCE(1, "\idle=mwait\" will be removed in 2012\"\n");
} else if (!strcmp(str, "halt")) {
/*
* When the boot option of idle=halt is added, halt is