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

From: Dou Liyang
Date: Tue Jul 11 2017 - 22:52:52 EST

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")

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.

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

parse the DMAR table and use it...

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

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)
+ acpi_early_init();
if (late_time_init)
- acpi_early_init();
#ifdef CONFIG_X86
if (efi_enabled(EFI_RUNTIME_SERVICES))

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.



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
cd lkp-tests
bin/lkp install job.yaml # job file is attached in this email
bin/lkp run job.yaml

Kernel Test Robot