<?xml version="1.0" encoding="UTF-8" standalone="yes" ?>
<!DOCTYPE bugzilla SYSTEM "https://bugzilla.yoctoproject.org/page.cgi?id=bugzilla.dtd">

<bugzilla version="5.0.6"
          urlbase="https://bugzilla.yoctoproject.org/"
          
          maintainer="it-coreprojects-helpdesk@linuxfoundation.org"
>

    <bug>
          <bug_id>13992</bug_id>
          
          <creation_ts>2020-07-28 07:57:39 +0000</creation_ts>
          <short_desc>qemumips testimage keeps failing</short_desc>
          <delta_ts>2021-05-06 15:14:06 +0000</delta_ts>
          <reporter_accessible>1</reporter_accessible>
          <cclist_accessible>1</cclist_accessible>
          <classification_id>10</classification_id>
          <classification>QA/Testing</classification>
          <product>Runtime Testing</product>
          <component>testimage</component>
          <version>unspecified</version>
          <rep_platform>x86</rep_platform>
          <op_sys>mips</op_sys>
          <bug_status>RESOLVED</bug_status>
          <resolution>WORKSFORME</resolution>
          
          
          <bug_file_loc></bug_file_loc>
          <status_whiteboard>AB-INT</status_whiteboard>
          <keywords></keywords>
          <priority>Medium+</priority>
          <bug_severity>normal</bug_severity>
          <target_milestone>3.4 M1</target_milestone>
          
          
          <everconfirmed>1</everconfirmed>
          <reporter name="Richard Purdie">richard.purdie</reporter>
          <assigned_to name="Victor Kamensky">victor.kamensky7</assigned_to>
          <cc>akuster808</cc>
    
    <cc>alexandre.belloni</cc>
    
    <cc>anuj.mittal</cc>
    
    <cc>bruce.ashfield</cc>
    
    <cc>flowergom</cc>
    
    <cc>jon.mason</cc>
    
    <cc>randy.macleod</cc>
    
    <cc>steve</cc>
          
          
          <cf_os>---</cf_os>
          <cf_regression_type>---</cf_regression_type>
          
          <cf_docchange>No (bug/feature does not impact docs)</cf_docchange>

      

      

      

          <comment_sort_order>oldest_to_newest</comment_sort_order>  
          <long_desc isprivate="0" >
    <commentid>87844</commentid>
    <comment_count>0</comment_count>
    <who name="Richard Purdie">richard.purdie</who>
    <bug_when>2020-07-28 07:57:39 +0000</bug_when>
    <thetext>https://autobuilder.yoctoproject.org/typhoon/#/builders/102/builds/763 (dunfell, qemumips-alt, core-iage-sato)
https://autobuilder.yoctoproject.org/typhoon/#/builders/102/builds/762 (master, qemumips-alt, core-image-sato-sdk)
https://autobuilder.yoctoproject.org/typhoon/#/builders/102/builds/760  (master, qemumips-alt, core-image-sato-sdk)</thetext>
  </long_desc><long_desc isprivate="0" >
    <commentid>87850</commentid>
    <comment_count>1</comment_count>
    <who name="Steve Sakoman">steve</who>
    <bug_when>2020-07-29 07:30:39 +0000</bug_when>
    <thetext>https://autobuilder.yoctoproject.org/typhoon/#/builders/102/builds/763 (dunfell, qemumips-alt, core-iage-sato, ubuntu2004-ty-2)</thetext>
  </long_desc><long_desc isprivate="0" >
    <commentid>87910</commentid>
    <comment_count>2</comment_count>
    <who name="akuster">akuster808</who>
    <bug_when>2020-08-11 12:05:39 +0000</bug_when>
    <thetext>trying to reproduce this on a slow centos7 system. One idea was load related so a slower system may replicate this.</thetext>
  </long_desc><long_desc isprivate="0" >
    <commentid>87915</commentid>
    <comment_count>3</comment_count>
    <who name="Steve Sakoman">steve</who>
    <bug_when>2020-08-12 11:15:21 +0000</bug_when>
    <thetext>https://autobuilder.yoctoproject.org/typhoon/#/builders/102/builds/804 (dunfell, qemumips-alt, core-image-sato-sdk, debian10-ty-3)</thetext>
  </long_desc><long_desc isprivate="0" >
    <commentid>87917</commentid>
    <comment_count>4</comment_count>
    <who name="Richard Purdie">richard.purdie</who>
    <bug_when>2020-08-12 13:55:15 +0000</bug_when>
    <thetext>qemu 5.1 release notes mention slight mips performance improvements which may be something else to investigate.</thetext>
  </long_desc><long_desc isprivate="0" >
    <commentid>87922</commentid>
    <comment_count>5</comment_count>
    <who name="Richard Purdie">richard.purdie</who>
    <bug_when>2020-08-13 05:48:47 +0000</bug_when>
    <thetext>Steve: Was khem&apos;s mips qemu cpu option included in that failed build?</thetext>
  </long_desc><long_desc isprivate="0" >
    <commentid>87923</commentid>
    <comment_count>6</comment_count>
    <who name="Steve Sakoman">steve</who>
    <bug_when>2020-08-13 06:59:22 +0000</bug_when>
    <thetext>Richard: Yes, this build included the &quot;qemumips: Use 34Kf CPU emulation&quot; patch</thetext>
  </long_desc><long_desc isprivate="0" >
    <commentid>87947</commentid>
    <comment_count>7</comment_count>
    <who name="akuster">akuster808</who>
    <bug_when>2020-08-14 09:22:21 +0000</bug_when>
    <thetext>I have a low end build system @ home ( 6 cores, 20GiG Ram).

If do invoke on bitbake to use all the cpus and then start the testimage,

qemu is starved of resources. I am seeing several testimage warning and errors.

I will try x86 to see if it has the same behavior.

1) Test requires ldd to be installed
WARNING: core-image-sato-sdk-1.0-r0 do_testimage: Couldn&apos;t login into serial console as root using blank password
WARNING: core-image-sato-sdk-1.0-r0 do_testimage: The output:
 root
&lt;&lt;&lt; run_serial(): command timed out after 60 seconds without output &gt;&gt;&gt;


2) Test requires systemtap to be installed
Startup finished in 21.329s (kernel) + 1min 55.569s (userspace) = 2min 16.898s.
Target boot time 136.898 exceeds systemd&apos;s TimeoutStartSec 90


Failed to reload daemon: Refusing to reload, not enough space available on /run/systemd. Currently, 14.3M are free, but a safety buffer of 16.0M is enforced.


3) Loads of dnf test failures</thetext>
  </long_desc><long_desc isprivate="0" >
    <commentid>87948</commentid>
    <comment_count>8</comment_count>
    <who name="akuster">akuster808</who>
    <bug_when>2020-08-14 09:22:35 +0000</bug_when>
    <thetext>Testimage local.conf

OEBUILDDIR = &quot;/home/akuster&quot;
OEBRANCH = &quot;master&quot;

SOURCE_MIRROR_URL = &quot;http://downloads.yoctoproject.org/mirror/sources/&quot;
SSTATE_MIRRORS = &quot;file://.* http://sstate.yoctoproject.org/dev/PATH;downloadfilename=PATH \n&quot;
DL_DIR = &quot;${OEBUILDDIR}/downloads/${OEBRANCH}&quot;
SSTATE_DIR = &quot;${OEBUILDDIR}/sstate/${OEBRANCH}&quot;
BB_HASHSERVE = &quot;auto&quot;
BB_SIGNATURE_HANDLER = &quot;OEEquivHash&quot;

SDKMACHINE = &quot;i686&quot;
PACKAGE_CLASSES = &quot;package_rpm package_deb package_ipk&quot;
IMAGE_CLASSES += &quot;testimage&quot;
TEST_QEMUBOOT_TIMEOUT = &apos;1500&apos;
INHERIT += &apos;image-buildinfo&apos;
IMAGE_BUILDINFO_VARS_append = &apos; IMAGE_BASENAME IMAGE_NAME&apos;
QEMU_USE_KVM = &apos;True&apos;
DISTRO = &quot;poky-altcfg&quot;</thetext>
  </long_desc><long_desc isprivate="0" >
    <commentid>87949</commentid>
    <comment_count>9</comment_count>
    <who name="akuster">akuster808</who>
    <bug_when>2020-08-14 09:23:25 +0000</bug_when>
    <thetext>Load:

bitbake core-image-full-cmdline core-image-sato core-image-sato-sdk -k

SDKMACHINE = &quot;i686&quot;
PACKAGE_CLASSES = &quot;package_rpm package_deb package_ipk&quot;
IMAGE_CLASSES += &quot;testimage&quot;
TEST_QEMUBOOT_TIMEOUT = &apos;1500&apos;
INHERIT += &apos;image-buildinfo&apos;
IMAGE_BUILDINFO_VARS_append = &apos; IMAGE_BASENAME IMAGE_NAME&apos;
QEMU_USE_KVM = &apos;True&apos;
DISTRO = &quot;poky-altcfg&quot;

MACHINE = &quot;qemumips64&quot;</thetext>
  </long_desc><long_desc isprivate="0" >
    <commentid>87950</commentid>
    <comment_count>10</comment_count>
    <who name="akuster">akuster808</who>
    <bug_when>2020-08-14 09:24:08 +0000</bug_when>
    <thetext>testimage command:

bitbake core-image-full-cmdline core-image-sato core-image-sato-sdk -c testimage</thetext>
  </long_desc><long_desc isprivate="0" >
    <commentid>87951</commentid>
    <comment_count>11</comment_count>
    <who name="akuster">akuster808</who>
    <bug_when>2020-08-14 09:24:21 +0000</bug_when>
    <thetext>Centos7.7</thetext>
  </long_desc><long_desc isprivate="0" >
    <commentid>88055</commentid>
    <comment_count>12</comment_count>
    <who name="Richard Purdie">richard.purdie</who>
    <bug_when>2020-08-27 23:13:49 +0000</bug_when>
    <thetext>https://autobuilder.yoctoproject.org/typhoon/#/builders/102/builds/863 (master, qemumips-alt, core-image-sato)</thetext>
  </long_desc><long_desc isprivate="0" >
    <commentid>88058</commentid>
    <comment_count>13</comment_count>
    <who name="Steve Sakoman">steve</who>
    <bug_when>2020-08-28 07:28:40 +0000</bug_when>
    <thetext>https://autobuilder.yoctoproject.org/typhoon/#/builders/60/builds/2358 (dunfell, qemumips, core-image-minimal, centos8-ty-2)</thetext>
  </long_desc><long_desc isprivate="0" >
    <commentid>88140</commentid>
    <comment_count>14</comment_count>
    <who name="akuster">akuster808</who>
    <bug_when>2020-09-10 21:52:52 +0000</bug_when>
    <thetext>(In reply to comment #7)
&gt; I have a low end build system @ home ( 6 cores, 20GiG Ram).
&gt; 
&gt; If do invoke on bitbake to use all the cpus and then start the testimage,
&gt; 
&gt; qemu is starved of resources. I am seeing several testimage warning and
&gt; errors.
&gt; 
&gt; I will try x86 to see if it has the same behavior.
&gt; 
&gt; 1) Test requires ldd to be installed
&gt; WARNING: core-image-sato-sdk-1.0-r0 do_testimage: Couldn&apos;t login into serial
&gt; console as root using blank password
&gt; WARNING: core-image-sato-sdk-1.0-r0 do_testimage: The output:
&gt;  root
&gt; &lt;&lt;&lt; run_serial(): command timed out after 60 seconds without output &gt;&gt;&gt;
&gt; 
&gt; 
&gt; 2) Test requires systemtap to be installed
&gt; Startup finished in 21.329s (kernel) + 1min 55.569s (userspace) = 2min
&gt; 16.898s.
&gt; Target boot time 136.898 exceeds systemd&apos;s TimeoutStartSec 90
&gt; 
&gt; 
&gt; Failed to reload daemon: Refusing to reload, not enough space available on
&gt; /run/systemd. Currently, 14.3M are free, but a safety buffer of 16.0M is
&gt; enforced.

I bumped the ram to everyone else&apos;s size
-m 512

and that seems to have addressed the that error.

&gt; 
&gt; 
&gt; 3) Loads of dnf test failures</thetext>
  </long_desc><long_desc isprivate="0" >
    <commentid>88141</commentid>
    <comment_count>15</comment_count>
    <who name="akuster">akuster808</who>
    <bug_when>2020-09-10 21:54:35 +0000</bug_when>
    <thetext>re-running tests with the &apos;renice&apos; changes</thetext>
  </long_desc><long_desc isprivate="0" >
    <commentid>88806</commentid>
    <comment_count>16</comment_count>
    <who name="Anuj Mittal">anuj.mittal</who>
    <bug_when>2020-12-23 06:55:34 +0000</bug_when>
    <thetext>I got this again today while testing gatesgarth:

https://autobuilder.yoctoproject.org/typhoon/#/builders/60/builds/2844/steps/10/logs/step1c</thetext>
  </long_desc><long_desc isprivate="0" >
    <commentid>89033</commentid>
    <comment_count>17</comment_count>
    <who name="Alexandre Belloni">alexandre.belloni</who>
    <bug_when>2021-01-26 18:35:56 +0000</bug_when>
    <thetext>Previous comment is about test_ping failing (I commented on the other bug).

However, this one is about qemu stalling a guest CPU and the guest kernel crashing because of that:
https://autobuilder.yoctoproject.org/typhoon/#/builders/74/builds/2942</thetext>
  </long_desc><long_desc isprivate="0" >
    <commentid>89178</commentid>
    <comment_count>18</comment_count>
    <who name="Minjae Kim">flowergom</who>
    <bug_when>2021-02-09 07:47:55 +0000</bug_when>
    <thetext>Happanded again:
https://autobuilder.yoctoproject.org/typhoon/#/builders/60/builds/3032/steps/14/logs/stdio</thetext>
  </long_desc><long_desc isprivate="0" >
    <commentid>89220</commentid>
    <comment_count>19</comment_count>
    <who name="Randy MacLeod">randy.macleod</who>
    <bug_when>2021-02-11 15:47:01 +0000</bug_when>
    <thetext>*** Bug 14224 has been marked as a duplicate of this bug. ***</thetext>
  </long_desc><long_desc isprivate="0" >
    <commentid>89331</commentid>
    <comment_count>20</comment_count>
    <who name="Victor Kamensky">victor.kamensky7</who>
    <bug_when>2021-02-20 04:10:39 +0000</bug_when>
    <thetext>Here is partial RCA, unfortunately it is still not clear what excactly the
problem. But what is clear that it is related to kernel page
migration/compaction function that does not work very well with MIPS
kernel HIGHMEM that is needed for 512Mb.

As per last note I&apos;ve tried MIPS kernel with disabled compaction, and
hang problem does not appear anymore. Removing CONFIG_COMPACTION from
32 MIPS kernel config may seem as reasonable workaround for purposes
of Yocto poky testing. Kernel compaction/migration code deals with
kernel memory fragmentation issues

o Reproduced problem on local setup. Under qemu with kernel debug observed
the following tracebacks:


(gdb) bt
#0  0x80195038 in queued_spin_lock_slowpath (lock=0x8cec163c, val=&lt;optimized out&gt;) at kernel/locking/qspinlock.c:382
#1  0x8030ad80 in spin_lock (lock=&lt;optimized out&gt;) at ./include/linux/spinlock.h:353
#2  follow_page_pte (pgmap=&lt;optimized out&gt;, flags=&lt;optimized out&gt;, pmd=&lt;optimized out&gt;, address=&lt;optimized out&gt;, vma=&lt;optimized out&gt;) at mm/gup.c:420
#3  follow_pmd_mask (vma=0x1, address=2138641893, pudp=0x8cfc57f4, flags=41479, ctx=&lt;optimized out&gt;) at mm/gup.c:609
#4  0x8030b278 in follow_pud_mask (ctx=&lt;optimized out&gt;, flags=&lt;optimized out&gt;, p4dp=&lt;optimized out&gt;, address=&lt;optimized out&gt;, vma=&lt;optimized out&gt;)
    at mm/gup.c:704
#5  follow_p4d_mask (ctx=&lt;optimized out&gt;, flags=&lt;optimized out&gt;, pgdp=&lt;optimized out&gt;, address=&lt;optimized out&gt;, vma=&lt;optimized out&gt;) at mm/gup.c:730
#6  follow_page_mask (ctx=&lt;optimized out&gt;, flags=&lt;optimized out&gt;, address=&lt;optimized out&gt;, vma=&lt;optimized out&gt;) at mm/gup.c:789
#7  __get_user_pages (tsk=0x0, mm=0x8cec1600, start=2138641893, nr_pages=1, gup_flags=41478, pages=0x8e4fbe08, vmas=0x8e4fbe04, locked=0x0)
    at mm/gup.c:1111
#8  0x8030b6e8 in __get_user_pages_locked (flags=&lt;optimized out&gt;, locked=&lt;optimized out&gt;, vmas=&lt;optimized out&gt;, pages=0x8e4fbe08, 
    nr_pages=&lt;optimized out&gt;, start=&lt;optimized out&gt;, mm=&lt;optimized out&gt;, tsk=&lt;optimized out&gt;) at mm/gup.c:1306
#9  __get_user_pages_remote (tsk=0x0, mm=0x8cec1600, start=2138641893, nr_pages=&lt;optimized out&gt;, gup_flags=&lt;optimized out&gt;, pages=0x8e4fbe08, 
    vmas=&lt;optimized out&gt;, locked=0x0) at mm/gup.c:1857
#10 0x80314808 in __access_remote_vm (tsk=0x0, mm=0x8cec1600, addr=2138641893, buf=0x8e4fbe7b, len=1, gup_flags=32768) at mm/memory.c:4694
#11 0x80314a40 in access_remote_vm (mm=&lt;optimized out&gt;, addr=&lt;optimized out&gt;, buf=&lt;optimized out&gt;, len=&lt;optimized out&gt;, gup_flags=&lt;optimized out&gt;)
    at mm/memory.c:4756
#12 0x80404164 in get_mm_cmdline (ppos=&lt;optimized out&gt;, count=&lt;optimized out&gt;, buf=0x5566d190 &quot;/bin/sh&quot;, mm=&lt;optimized out&gt;) at fs/proc/base.c:301
#13 get_task_cmdline (pos=&lt;optimized out&gt;, count=&lt;optimized out&gt;, buf=&lt;optimized out&gt;, tsk=&lt;optimized out&gt;) at fs/proc/base.c:352
#14 proc_pid_cmdline_read (file=&lt;optimized out&gt;, buf=0x5566d190 &quot;/bin/sh&quot;, count=&lt;optimized out&gt;, pos=0x8e4fbf00) at fs/proc/base.c:368
#15 0x8035bb8c in vfs_read (file=0x8e5af0c0, buf=0x5566d190 &quot;/bin/sh&quot;, count=&lt;optimized out&gt;, pos=0x8e4fbf00) at fs/read_write.c:479
#16 0x8035d474 in ksys_read (fd=&lt;optimized out&gt;, buf=0x5566d190 &quot;/bin/sh&quot;, count=20) at fs/read_write.c:633
#17 0x80118304 in handle_sys () at arch/mips/kernel/scall32-o32.S:99
Backtrace stopped: frame did not save the PC

or another variant

(gdb) bt
#0  0x80196eb8 in queued_spin_lock_slowpath (lock=0x8e31b8fc, val=&lt;optimized out&gt;) at kernel/locking/qspinlock.c:382
#1  0x80198848 in queued_spin_lock (lock=&lt;optimized out&gt;) at ./include/asm-generic/qspinlock.h:81
#2  do_raw_spin_lock (lock=0x8e31b8fc) at kernel/locking/spinlock_debug.c:113
#3  0x80314b54 in spin_lock (lock=&lt;optimized out&gt;) at ./include/linux/spinlock.h:353
#4  zap_pte_range (tlb=0x8c80fba8, vma=&lt;optimized out&gt;, pmd=&lt;optimized out&gt;, addr=1432166400, end=1433374720, details=0x0) at mm/memory.c:1048
#5  0x80315b10 in zap_pmd_range (details=&lt;optimized out&gt;, end=&lt;optimized out&gt;, addr=1432166400, pud=&lt;optimized out&gt;, vma=&lt;optimized out&gt;, 
    tlb=&lt;optimized out&gt;) at mm/memory.c:1194
#6  zap_pud_range (details=&lt;optimized out&gt;, end=&lt;optimized out&gt;, addr=&lt;optimized out&gt;, p4d=&lt;optimized out&gt;, vma=&lt;optimized out&gt;, tlb=&lt;optimized out&gt;)
    at mm/memory.c:1223
#7  zap_p4d_range (details=&lt;optimized out&gt;, end=&lt;optimized out&gt;, addr=&lt;optimized out&gt;, pgd=&lt;optimized out&gt;, vma=&lt;optimized out&gt;, tlb=&lt;optimized out&gt;)
    at mm/memory.c:1244
#8  unmap_page_range (tlb=0x8c80fba8, vma=0x8dca1f00, addr=1432166400, end=1433374720, details=0x0) at mm/memory.c:1265
#9  0x80315e88 in unmap_single_vma (details=&lt;optimized out&gt;, end_addr=&lt;optimized out&gt;, start_addr=&lt;optimized out&gt;, vma=&lt;optimized out&gt;, 
    tlb=&lt;optimized out&gt;) at mm/memory.c:1310
#10 unmap_vmas (tlb=0x8c80fba8, vma=0x8dca1f00, start_addr=0, end_addr=4294967295) at mm/memory.c:1342
#11 0x8031ed28 in exit_mmap (mm=0x8e31b8c0) at mm/mmap.c:3179
#12 0x801322a4 in __mmput (mm=&lt;optimized out&gt;) at kernel/fork.c:1093
#13 mmput (mm=0x8e31b8c0) at kernel/fork.c:1114
#14 0x8013b134 in exit_mm () at kernel/exit.c:482
#15 do_exit (code=&lt;optimized out&gt;) at kernel/exit.c:792
#16 0x8010f998 in die (str=0x80ef0cf0 &quot;Kernel bug detected&quot;, regs=0x8c80fd30) at arch/mips/kernel/traps.c:415
#17 0x80110150 in die_if_kernel (regs=&lt;optimized out&gt;, str=&lt;optimized out&gt;) at ./arch/mips/include/asm/ptrace.h:167
#18 do_trap_or_bp (regs=0x8c80fd30, code=12, si_code=&lt;optimized out&gt;, str=0x80ef0d40 &quot;Trap&quot;) at arch/mips/kernel/traps.c:990
#19 0x80110580 in do_tr (regs=0x8c80fd30) at arch/mips/kernel/traps.c:1141
#20 0x801092b8 in handle_tr () at arch/mips/kernel/genex.S:553
Backtrace stopped: frame did not save the PC

In all cases page lock seems to be corrupted. Example:

(gdb) p *lock
$3 = {{val = {counter = 257}, {tail = 0, locked_pending = 257}, {reserved = &quot;\000&quot;, pending = 1 &apos;\001&apos;, locked = 1 &apos;\001&apos;}}}

o It turns out and as last traceback suggests, above crashes are
actually secondary problem. They do really hit corrupted lock, but first
issue is really triggered by BUG_ON in migration_entry_to_page

(gdb) bt
#0  0x8034d05c in __BUG_ON (condition=&lt;optimized out&gt;) at ./arch/mips/include/asm/bug.h:30
#1  migration_entry_to_page (entry=...) at ./include/linux/swapops.h:197
#2  __migration_entry_wait (mm=&lt;optimized out&gt;, ptep=&lt;optimized out&gt;, ptl=&lt;optimized out&gt;) at mm/migrate.c:328
#3  0x80317b74 in do_swap_page (vmf=0x8dcafe78) at mm/memory.c:3115
#4  0x80318af8 in handle_pte_fault (vmf=&lt;optimized out&gt;) at mm/memory.c:4239
#5  __handle_mm_fault (flags=&lt;optimized out&gt;, address=&lt;optimized out&gt;, vma=&lt;optimized out&gt;) at mm/memory.c:4370
#6  handle_mm_fault (vma=0x8e0ae060, address=&lt;optimized out&gt;, flags=596) at mm/memory.c:4407
#7  0x80cc5784 in __do_page_fault (address=&lt;optimized out&gt;, write=&lt;optimized out&gt;, regs=&lt;optimized out&gt;) at arch/mips/mm/fault.c:155
#8  do_page_fault (regs=0x8dcaff28, write=0, address=1433989548) at arch/mips/mm/fault.c:338
#9  0x801227c4 in tlb_do_page_fault_0 () at arch/mips/mm/tlbex-fault.S:27
Backtrace stopped: frame did not save the PC


(gdb) f 1
#1  migration_entry_to_page (entry=...) at ./include/linux/swapops.h:197
197		BUG_ON(!PageLocked(compound_head(p)));
(gdb) list
192		struct page *p = pfn_to_page(swp_offset(entry));
193		/*
194		 * Any use of migration entries may only occur while the
195		 * corresponding page is locked
196		 */
197		BUG_ON(!PageLocked(compound_head(p)));
198		return p;
199	}

o Further debugging of mips highmem and kernel migration/compaction did not
produce anything useful. Code is quite complicated and logic is not clear.

o Run experiment, where otherwise all same setup, I&apos;ve disabled kernel
migration/compaction code, and hand issue was not observed anymore. Here is
diff kernel config diff. Essential part is to disable CONFIG_COMPACTION,
i.e &apos;CONFIG_COMPACTION is not set&apos; it would automatically clear
CONFIG_BALLOON_COMPACTION=y and CONFIG_MIGRATION=y because of dependency.

606,607c606
&lt; CONFIG_BALLOON_COMPACTION=y
&lt; CONFIG_COMPACTION=y
---
&gt; # CONFIG_COMPACTION is not set
609d607
&lt; CONFIG_MIGRATION=y

o Removing CONFIG_COMPACTION from 32 MIPS kernel config may seem
as reasonable workaround for purposes of Yocto poky testing.
Kernel compaction/migration code deals with kernel memory
fragmentation issues and given that test is relatively short,
system would be OK even without memory compaction.

o As other experiment under poky test load with kernel breakpoint
in compaction code I observed that compation did not trigger at
all through first half part of the test. And actually as soon it
got triggered mention BUG_ON was hit on page that was involved
in migration.</thetext>
  </long_desc><long_desc isprivate="0" >
    <commentid>89332</commentid>
    <comment_count>21</comment_count>
    <who name="Richard Purdie">richard.purdie</who>
    <bug_when>2021-02-20 11:34:28 +0000</bug_when>
    <thetext>Thanks Victor, its great analysis, that might be a good enough fix for our needs. Bruce, should we enable this on 32 bit mips kernels?</thetext>
  </long_desc><long_desc isprivate="0" >
    <commentid>89345</commentid>
    <comment_count>22</comment_count>
    <who name="Bruce Ashfield">bruce.ashfield</who>
    <bug_when>2021-02-23 01:15:41 +0000</bug_when>
    <thetext>(In reply to comment #21)
&gt; Thanks Victor, its great analysis, that might be a good enough fix for our
&gt; needs. Bruce, should we enable this on 32 bit mips kernels?

I&apos;m ok with changing those values on the 32bit mips kernels. I can prepare change to the meta-data for testing on the AB.</thetext>
  </long_desc><long_desc isprivate="0" >
    <commentid>89346</commentid>
    <comment_count>23</comment_count>
    <who name="Bruce Ashfield">bruce.ashfield</who>
    <bug_when>2021-02-23 02:06:25 +0000</bug_when>
    <thetext>http://git.yoctoproject.org/cgit.cgi/poky-contrib/commit/?h=zedd/kernel&amp;id=cfc7e124bd3e0ccdc1ba77e32991a839f427f92b

Is available for testing.  I&apos;ll also include it in my next consolidated pull request.</thetext>
  </long_desc><long_desc isprivate="0" >
    <commentid>89449</commentid>
    <comment_count>24</comment_count>
    <who name="Alexandre Belloni">alexandre.belloni</who>
    <bug_when>2021-03-01 00:29:00 +0000</bug_when>
    <thetext>This is an occurrence from last week:

https://autobuilder.yoctoproject.org/typhoon/#/builders/60/builds/3106/steps/13/logs/stdio</thetext>
  </long_desc><long_desc isprivate="0" >
    <commentid>90290</commentid>
    <comment_count>25</comment_count>
    <who name="Randy MacLeod">randy.macleod</who>
    <bug_when>2021-05-06 15:14:06 +0000</bug_when>
    <thetext>Not seen since the page table code changes and moving the rootfs to tmpfs.</thetext>
  </long_desc>
      
      

    </bug>

</bugzilla>