From cdaab4a0d330f70c0e5ad8c3f7c65c2e375ea180 Mon Sep 17 00:00:00 2001 From: Len Brown Date: Fri, 1 Apr 2011 15:41:17 -0400 Subject: x86 idle: deprecate "no-hlt" cmdline param We'd rather that modern machines not check if HLT works on every entry into idle, for the benefit of machines that had marginal electricals 15-years ago. If those machines are still running the upstream kernel, they can use "idle=poll". The only difference will be that they'll now invoke HLT in machine_hlt(). cc: x86@kernel.org # .39.x Signed-off-by: Len Brown --- Documentation/feature-removal-schedule.txt | 11 +++++++++++ arch/x86/kernel/cpu/bugs.c | 1 + 2 files changed, 12 insertions(+) diff --git a/Documentation/feature-removal-schedule.txt b/Documentation/feature-removal-schedule.txt index fc505c1b476..f1b0eb02aa1 100644 --- a/Documentation/feature-removal-schedule.txt +++ b/Documentation/feature-removal-schedule.txt @@ -24,6 +24,17 @@ Who: Len Brown ---------------------------- +What: x86_32 "no-hlt" cmdline param +When: 2012 +Why: remove a branch from idle path, simplify code used by everybody. + This option disabled the use of HLT in idle and machine_halt() + for hardware that was flakey 15-years ago. Today we have + "idle=poll" that removed HLT from idle, and so if such a machine + is still running the upstream kernel, "idle=poll" is likely sufficient. +Who: Len Brown + +---------------------------- + What: PRISM54 When: 2.6.34 diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c index c39576cb301..525514cf33c 100644 --- a/arch/x86/kernel/cpu/bugs.c +++ b/arch/x86/kernel/cpu/bugs.c @@ -19,6 +19,7 @@ static int __init no_halt(char *s) { + WARN_ONCE(1, "\"no-hlt\" is deprecated, please use \"idle=poll\"\n"); boot_cpu_data.hlt_works_ok = 0; return 1; } -- cgit v1.2.3-70-g09d2