Re: [x86/time] f61a8e12b5: ACPI_Error:Table[DMAR]is_not_invalidated_during_early_boot_stage(#/tbxface-#)

[Dou Liyang]

Hi, Xiaolong

Thank you very much for testing. I have got the reason why the ACPI
error happened and will give a fix patch below.

Also cc ACPI maintainers..

At 07/08/2017 11:48 AM, kernel test robot wrote:
> FYI, we noticed the following commit:
>
> commit: f61a8e12b5972879f8decfe059e54c813dc4416b ("x86/time: Initialize interrupt mode behind timer init")
> url: https://github.com/0day-ci/linux/commits/Dou-Liyang/Unify-the-interrupt-delivery-mode-and-do-its-setup-in-advance/20170705-124610
>
>
> in testcase: will-it-scale
> with following parameters:
>
> 	nr_task: 50%
> 	mode: process
> 	test: writeseek3
> 	cpufreq_governor: performance
>
> test-description: Will It Scale takes a testcase and runs it from 1 through to n parallel copies to see if the testcase will scale. It builds both a process and threads based test in order to see any differences between the two.
> test-url: https://github.com/antonblanchard/will-it-scale
>
>
> on test machine: 88 threads Intel(R) Xeon(R) CPU E5-2699 v4 @ 2.20GHz with 64G memory
>
> caused below changes (please refer to attached dmesg/kmsg for entire log/backtrace):
>
>
> +-------------------------------------------------------------------------------+------------+------------+
> |                                                                               | d021c73124 | f61a8e12b5 |
> +-------------------------------------------------------------------------------+------------+------------+
> | boot_successes                                                                | 0          | 6          |
> | boot_failures                                                                 | 2          | 4          |
> | invoked_oom-killer:gfp_mask=0x                                                | 2          |            |
> | Mem-Info                                                                      | 2          |            |
> | Kernel_panic-not_syncing:Out_of_memory_and_no_killable_processes              | 2          |            |
> | ACPI_Error:Table[DMAR]is_not_invalidated_during_early_boot_stage(#/tbxface-#) | 0          | 4          |
> | WARNING:at_mm/early_ioremap.c:#check_early_ioremap_leak                       | 0          | 4          |
> +-------------------------------------------------------------------------------+------------+------------+
>
>
>
> kern  :info  : [    0.005000] tsc: Fast TSC calibration using PIT
> kern  :info  : [    0.006000] tsc: Detected 2194.957 MHz processor
> kern  :info  : [    0.007000] Calibrating delay loop (skipped), value calculated using timer frequency.. 4389.91 BogoMIPS (lpj=2194957)
> kern  :info  : [    0.008002] pid_max: default: 90112 minimum: 704
> kern  :info  : [    0.009034] ACPI: Core revision 20170303
> kern  :err   : [    0.010002] ACPI Error: Table [DMAR] is not invalidated during early boot stage (20170303/tbxface-193)

Here is the ACPI error.

The reason:
-----------

As we know, Linux divides the ACPI table management into two stages:
1) the early stage:
  the mapped ACPI tables is temporary and should be unmapped before the
early stage ends.

2) the late stage.
  the mapped ACPI tables is permanent.

And Linux uses *acpi_permanent_mmap* to distinguish the early stage and
the late stage. the default of *acpi_permanent_mmap* is false and will
be set to true in *acpi_early_init()*, which means that Linux regards
*acpi_early_init()* as the dividing line.

Linux maps the ACPI DMAR table in the late stage, But this patch make 
the mapping earlier in the early stage, so the ACPI error happened.

The solution:
-------------

There are two solution we can use:

1) After use the DMAR table, we unmap it, which likes following

 acpi_get_table();
 parse the DMAR table and use it...
 acpi_put_table();

2) Invoke the *acpi_early_init()* earlier.

The 1) has influence on the initialization of IOMMU, not work well.
The 2) is suitable, and it also can make the change of interrupt trigger 
type earlier than Linux enter into the final interrupt delivery
mode.

The patch:
----------
  it will be added in my next version.


diff --git a/init/main.c b/init/main.c
index df58a41..7a09467 100644
--- a/init/main.c
+++ b/init/main.c
@@ -654,12 +654,12 @@ asmlinkage __visible void __init start_kernel(void)
        kmemleak_init();
        setup_per_cpu_pageset();
        numa_policy_init();
+       acpi_early_init();
        if (late_time_init)
                late_time_init();
        calibrate_delay();
        pidmap_init();
        anon_vma_init();
-       acpi_early_init();
 #ifdef CONFIG_X86
        if (efi_enabled(EFI_RUNTIME_SERVICES))
                efi_enter_virtual_mode();

BTY, cc Lee

I try to invoke acpi_early_init() earlier before
timekeeping_init() for accessing ACPI TAD device to set system clock.
Now the testing is OK, but There are a lot of operations between them,
I think we need more investigation.


Thanks,

	dou.

> kern  :info  : [    0.125364] ACPI: 4 ACPI AML tables successfully acquired and loaded
> kern  :info  : [    0.126116] Security Framework initialized
> kern  :info  : [    0.127003] SELinux:  Initializing.
> kern  :debug : [    0.128012] SELinux:  Starting in permissive mode
> kern  :info  : [    0.131850] Dentry cache hash table entries: 8388608 (order: 14, 67108864 bytes)
>
>
> To reproduce:
>
>         git clone https://github.com/01org/lkp-tests.git
>         cd lkp-tests
>         bin/lkp install job.yaml  # job file is attached in this email
>         bin/lkp run     job.yaml
>
>
>
> Thanks,
> Kernel Test Robot