On Tue, Nov 22, 2011 at 08:54:12AM -0500, Konrad Rzeszutek Wilk wrote: > > Subject : Regression in 3.1 causes Xen to use wrong idle routine > > Submitter : Stefan Bader <stefan.bader@xxxxxxxxxxxxx> > > Date : 2011-10-26 10:24 > > Message-ID : 4EA7DFD1.9060608@xxxxxxxxxxxxx > > References : http://marc.info/?l=linux-acpi&m=131962467924564&w=2 > > The patch mentioned in http://mid.gmane.org/20111115144004.GE22675@xxxxxxxxxxxxxxxxxxx > should do it. But the patch needs an Ack from ACPI/x86 folks. This patch (mentioned in the URL above) fixes the issue. Could it be applied to the x86 tree for 3.2 or get an Ack, please? >From 4f10ec7a7b9ff24657696aa98f25bcecde247373 Mon Sep 17 00:00:00 2001 From: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx> Date: Mon, 21 Nov 2011 18:02:02 -0500 Subject: [PATCH] xen/pm_idle: Make pm_idle be default_idle under Xen. This patch: commit d91ee5863b71e8c90eaf6035bff3078a85e2e7b5 Author: Len Brown <len.brown@xxxxxxxxx> 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. idea was to have one call - disable_cpuidle() which would make pm_idle not be molested by other code. It disallows cpuidle_idle_call and acpi_idle_call to not set pm_idle (which is excellent). But the amd_e400_idle and mwait_idle can still setup pm_idle which we really do not want. In case of mwait_idle we can hit some instances where: Brought up 2 CPUs invalid opcode: 0000 [#1] SMP CPU 1 Modules linked in: Pid: 0, comm: swapper Not tainted 3.1.0-0.rc6.git0.3.fc16.x86_64 #1 RIP: e030:[<ffffffff81015d1d>] [<ffffffff81015d1d>] mwait_idle+0x6f/0xb4 RSP: e02b:ffff8801d28ddf10 EFLAGS: 00010082 RAX: ffff8801d28dc010 RBX: ffff8801d28ddfd8 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000001 RBP: ffff8801d28ddf10 R08: 0000000000000000 R09: 0000000000000001 R10: 0000000000000001 R11: ffff8801d28ddfd8 R12: ffffffff81b590d0 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8801dff81000(0000) knlGS:0000000000000000 CS: e033 DS: 002b ES: 002b CR0: 000000008005003b CR2: 0000000000000000 CR3: 0000000001a05000 CR4: 0000000000002660 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000000 Process swapper (pid: 0, threadinfo ffff8801d28dc000, task ffff8801d28cae60) Stack: ffff8801d28ddf40 ffffffff8100e2ed ffff8801dff8e390 c136dfe72feab515 0000000000000000 0000000000000000 ffff8801d28ddf50 ffffffff8149ee78 0000000000000000 0000000000000000 0000000000000000 0000000000000000 Call Trace: [<ffffffff8100e2ed>] cpu_idle+0xae/0xe8 [<ffffffff8149ee78>] cpu_bringup_and_idle+0xe/0x10 RIP [<ffffffff81015d1d>] mwait_idle+0x6f/0xb4 RSP <ffff8801d28ddf10> RH BZ #739499 and Ubuntu #881076 In case of amd_e400_idle we don't get so spectacular crashes, but we do end up making an MSR which is trapped in the hypervisor, and then follow it up with a yield hypercall. Meaning we end up going to hypervisor twice instead of just once. Lets make pm_idle be default_idle to take care of that. Reported-by: Stefan Bader <stefan.bader@xxxxxxxxxxxxx> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx> --- arch/x86/include/asm/system.h | 1 + arch/x86/kernel/process.c | 8 ++++++++ arch/x86/xen/setup.c | 2 +- 3 files changed, 10 insertions(+), 1 deletions(-) diff --git a/arch/x86/include/asm/system.h b/arch/x86/include/asm/system.h index c2ff2a1..2d2f01c 100644 --- a/arch/x86/include/asm/system.h +++ b/arch/x86/include/asm/system.h @@ -401,6 +401,7 @@ extern unsigned long arch_align_stack(unsigned long sp); extern void free_init_pages(char *what, unsigned long begin, unsigned long end); void default_idle(void); +bool set_pm_idle_to_default(void); void stop_this_cpu(void *dummy); diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c index 1f7f8c8..336b299 100644 --- a/arch/x86/kernel/process.c +++ b/arch/x86/kernel/process.c @@ -404,6 +404,14 @@ void default_idle(void) EXPORT_SYMBOL(default_idle); #endif +bool set_pm_idle_to_default() +{ + if (!pm_idle) { + pm_idle = default_idle; + return true; + } + return false; +} void stop_this_cpu(void *dummy) { local_irq_disable(); diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c index 46d6d21..7506181 100644 --- a/arch/x86/xen/setup.c +++ b/arch/x86/xen/setup.c @@ -448,6 +448,6 @@ void __init xen_arch_setup(void) #endif disable_cpuidle(); boot_option_idle_override = IDLE_HALT; - + WARN_ON(!set_pm_idle_to_default()); fiddle_vdso(); } -- 1.7.7.3 _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/linux-pm
