From mboxrd@z Thu Jan 1 00:00:00 1970 From: Konrad Rzeszutek Wilk Subject: [PATCH 1/3] cpuidle: If disable_cpuidle() is called, set pm_idle to default_idle. Date: Tue, 8 Nov 2011 16:15:12 -0500 Message-ID: <1320786914-10541-2-git-send-email-konrad.wilk@oracle.com> References: <1320786914-10541-1-git-send-email-konrad.wilk@oracle.com> Return-path: In-Reply-To: <1320786914-10541-1-git-send-email-konrad.wilk@oracle.com> Sender: linux-kernel-owner@vger.kernel.org To: linux-kernel@vger.kernel.org, x86@kernel.org, len.brown@intel.com, tglx@linutronix.de, jeremy@goop.org, hpa@zytor.com, bp@alien8.de, tj@kernel.org, trenn@suse.de Cc: mingo@redhat.com, xen-devel@lists.xensource.com, Konrad Rzeszutek Wilk , stable@kernel.org List-Id: xen-devel@lists.xenproject.org . however we ignore the disable_cpuidle() directive and in select_idle_routine() set it to type preferred by the CPU. This is a regression introduced by commit a0bfa1373859e9d11dc92561a8667588803e42d8 Author: Len Brown Date: Fri Apr 1 19:34:59 2011 -0400 cpuidle: stop depending on pm_idle specifically this patch: commit d91ee5863b71e8c90eaf6035bff3078a85e2e7b5 Author: Len Brown Date: Fri Apr 1 18:28:35 2011 -0400 cpuidle: replace xen access to x86 pm_idle and default_idle ..scribble on pm_idle and access default_idle, have it simply disable_cpuidle() so acpi_idle will not load and architecture default HLT will be used. .. but the default HLT does not get used. Instead we end up in the situation that select_idle_routine() is called from arch/x86/kernel/cpu/common.c and if we called cpuidle_disable(), then the pm_idle is not set, and we end up setting pm_idle to mwait_idle or amd_e400_idle. This patch uses the cpuidle_disabled() functionality and makes select_idle_routine() adhere to that. Reported-by: Stefan Bader Signed-off-by: Konrad Rzeszutek Wilk CC: Thomas Gleixner CC: Ingo Molnar CC: "H. Peter Anvin" CC: x86@kernel.org CC: Len Brown CC: Borislav Petkov CC: Tejun Heo CC: Thomas Renninger CC: stable@kernel.org --- arch/x86/kernel/process.c | 5 +++++ include/linux/cpuidle.h | 2 ++ 2 files changed, 7 insertions(+), 0 deletions(-) diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c index e7e3b01..1f7f8c8 100644 --- a/arch/x86/kernel/process.c +++ b/arch/x86/kernel/process.c @@ -14,6 +14,7 @@ #include #include #include +#include #include #include #include @@ -587,6 +588,10 @@ void __cpuinit select_idle_routine(const struct cpuinfo_x86 *c) if (pm_idle) return; + if (cpuidle_disabled()) { + pm_idle = default_idle; + return; + } if (cpu_has(c, X86_FEATURE_MWAIT) && mwait_usable(c)) { /* * One CPU supports mwait => All CPUs supports mwait diff --git a/include/linux/cpuidle.h b/include/linux/cpuidle.h index b51629e..123fe9e 100644 --- a/include/linux/cpuidle.h +++ b/include/linux/cpuidle.h @@ -122,6 +122,7 @@ struct cpuidle_driver { }; #ifdef CONFIG_CPU_IDLE +extern int cpuidle_disabled(void); extern void disable_cpuidle(void); extern int cpuidle_idle_call(void); @@ -137,6 +138,7 @@ extern int cpuidle_enable_device(struct cpuidle_device *dev); extern void cpuidle_disable_device(struct cpuidle_device *dev); #else +static inline int cpuidle_disabled(void) { return 1; } static inline void disable_cpuidle(void) { } static inline int cpuidle_idle_call(void) { return -ENODEV; } -- 1.7.7.1