lkml.org 
[lkml]   [2019]   [Apr]   [16]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: next/master boot bisection: next-20190215 on beaglebone-black
----- On Apr 16, 2019, at 2:54 PM, Dan Williams dan.j.williams@intel.com wrote:

> On Thu, Apr 11, 2019 at 1:54 PM Guenter Roeck <groeck@google.com> wrote:
> [..]
>> > > Boot tests report
>> > >
>> > > Qemu test results:
>> > > total: 345 pass: 345 fail: 0
>> > >
>> > > This is on top of next-20190410 with CONFIG_SHUFFLE_PAGE_ALLOCATOR=y
>> > > and the known crashes fixed.
>> >
>> > In addition to CONFIG_SHUFFLE_PAGE_ALLOCATOR=y you also need the
>> > kernel command line option "page_alloc.shuffle=1"
>> >
>> > ...so I doubt you are running with shuffling enabled. Another way to
>> > double check is:
>> >
>> > cat /sys/module/page_alloc/parameters/shuffle
>>
>> Yes, you are right. Because, with it enabled, I see:
>>
>> Kernel command line: rdinit=/sbin/init page_alloc.shuffle=1 panic=-1
>> console=ttyAMA0,115200 page_alloc.shuffle=1
>> ------------[ cut here ]------------
>> WARNING: CPU: 0 PID: 0 at ./include/linux/jump_label.h:303
>> page_alloc_shuffle+0x12c/0x1ac
>> static_key_enable(): static key 'page_alloc_shuffle_key+0x0/0x4' used
>> before call to jump_label_init()
>
> This looks to be specific to ARM never having had to deal with
> DEFINE_STATIC_KEY_TRUE in the past.
>
> I am able to avoid this warning by simply not enabling JUMP_LABEL
> support in my build.

Looking into this some more, it looks like I was on the wrong track
with my large branch offset theory. Is it just possible that
page_alloc_shuffle() ends up using jump labels before they are
initialized ? Perhaps this has something to do with how early
the page_alloc.shuffle=1 kernel parameter is handled.

Thanks,

Mathieu


--
Mathieu Desnoyers
EfficiOS Inc.
http://www.efficios.com

\
 
 \ /
  Last update: 2019-04-16 22:06    [W:0.098 / U:7.164 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site