Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753471Ab1DBGX1 (ORCPT ); Sat, 2 Apr 2011 02:23:27 -0400 Received: from vms173017pub.verizon.net ([206.46.173.17]:42466 "EHLO vms173017pub.verizon.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753869Ab1DBGXY (ORCPT ); Sat, 2 Apr 2011 02:23:24 -0400 From: Len Brown To: linux-pm@lists.linux-foundation.org Cc: linux-kernel@vger.kernel.org, Len Brown , x86@kernel.org, stable@kernel.org Subject: [PATCH 06/18] x86 idle: deprecate mwait_idle() and "idle=mwait" cmdline param Date: Sat, 02 Apr 2011 02:22:48 -0400 Message-id: <7eaf17a79efa960a4a317d3cb8651375ed61f5a6.1301724243.git.len.brown@intel.com> X-Mailer: git-send-email 1.7.5.rc0 In-reply-to: <1301725380-10579-1-git-send-email-lenb@kernel.org> References: <1301725380-10579-1-git-send-email-lenb@kernel.org> In-reply-to: References: X-Patchwork-Hint: ignore Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2205 Lines: 64 From: Len Brown 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 But mwait_idle() has been replaced by the more general mwait_idle_with_hints(), which handles both C1 and deeper C-states.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 will support it. cc: x86@kernel.org cc: stable@kernel.org Signed-off-by: Len Brown --- Documentation/feature-removal-schedule.txt | 7 +++++++ arch/x86/kernel/process.c | 1 + 2 files changed, 8 insertions(+), 0 deletions(-) diff --git a/Documentation/feature-removal-schedule.txt b/Documentation/feature-removal-schedule.txt index f587159..9ee4a2c 100644 --- a/Documentation/feature-removal-schedule.txt +++ b/Documentation/feature-removal-schedule.txt @@ -35,6 +35,13 @@ Who: Len Brown ---------------------------- +What: x86 "idle=mwait" cmdline param +When: 2.6.40 +Why: simplify x86 idle code +Who: Len Brown + +---------------------------- + What: PRISM54 When: 2.6.34 diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c index 17b8771..1f64501 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 2.6.40\"\n"); } else if (!strcmp(str, "halt")) { /* * When the boot option of idle=halt is added, halt is -- 1.7.5.rc0 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/