New: Highmem support broken on kernels greater 5.15.x on ppc32?

Bug 215781 [email protected] 1 participant 7 messages Mar 30, 2022 – Apr 18, 2022

Share & tools

[email protected]

author

2022-03-30 22:53 UTC #0 lore raw

https://bugzilla.kernel.org/show_bug.cgi?id=215781

            Bug ID: 215781
           Summary: Highmem support broken on kernels greater 5.15.x on
                    ppc32?
           Product: Platform Specific/Hardware
           Version: 2.5
    Kernel Version: 5.16.18
          Hardware: PPC-32
                OS: Linux
              Tree: Mainline
            Status: NEW
          Severity: normal
          Priority: P1
         Component: PPC-32
          Assignee: [email protected]
          Reporter: [email protected]
        Regression: Yes

Created attachment 300664
--> https://bugzilla.kernel.org/attachment.cgi?id=300664&action=edit
dmesg (5.16.18, PowerMac G4 DP)

Noticed my G4 DP ran a bit sluggish... Turned out it uses only 614664K of 2097152K RAM. Happens on both kernel 5.16.18 and 5.17.1. Kernels 5.15 and before work as expected.

It seems to be a problem with highmem as 5.16.18 and 5.1.7.1 show 0K highmem. CONFIG_HIGHMEM=y is of course set.

Kernel 5.16.18 says:
[...]
Top of RAM: 0x80000000, Total RAM: 0x80000000
Memory hole size: 0MB
Zone ranges:

  DMA      [mem 0x0000000000000000-0x0000000027ffffff]
  Normal   empty
  HighMem  [mem 0x0000000028000000-0x000000007fffffff]

Movable zone start for each node
Early memory node ranges
node 0: [mem 0x0000000000000000-0x000000007fffffff]
Initmem setup node 0 [mem 0x0000000000000000-0x000000007fffffff]
percpu: Embedded 12 pages/cpu s19404 r8192 d21556 u49152
pcpu-alloc: s19404 r8192 d21556 u49152 alloc=12*4096
pcpu-alloc: [0] 0 [0] 1
Built 1 zonelists, mobility grouping on. Total pages: 522848 Kernel command line: ro root=/dev/sda5 zswap.max_pool_percent=16 zswap.zpool=z3fold slub_debug=FZP page_poison=1 [email protected]/eth0,[email protected]/70:85:C2:30:EC:01 Dentry cache hash table entries: 131072 (order: 7, 524288 bytes, linear) Inode-cache hash table entries: 65536 (order: 6, 262144 bytes, linear) mem auto-init: stack:__user(zero), heap alloc:off, heap free:off Kernel virtual memory layout:

  * 0xffbbf000..0xfffff000  : fixmap
  * 0xff400000..0xff800000  : highmem PTEs
  * 0xff115000..0xff400000  : early ioremap
  * 0xe9000000..0xff115000  : vmalloc & ioremap
  * 0xb0000000..0xc0000000  : modules

Memory: 614664K/2097152K available (8828K kernel code, 488K rwdata, 1664K rodata, 1316K init, 381K bss, 1482488K reserved, 0K cma-reserved, 0K highmem) [...]

On kernel 5.15.23 I got highmem as expected:
[...]
Top of RAM: 0x80000000, Total RAM: 0x80000000
Memory hole size: 0MB
Zone ranges:

  DMA      [mem 0x0000000000000000-0x0000000027ffffff]
  Normal   empty
  HighMem  [mem 0x0000000028000000-0x000000007fffffff]

  * 0xffbbf000..0xfffff000  : fixmap
  * 0xff400000..0xff800000  : highmem PTEs
  * 0xff115000..0xff400000  : early ioremap
  * 0xe9000000..0xff115000  : vmalloc & ioremap
  * 0xb0000000..0xc0000000  : modules

Memory: 2056460K/2097152K available (8688K kernel code, 488K rwdata, 1644K rodata, 1316K init, 377K bss, 40692K reserved, 0K cma-reserved, 1441792K highmem)
[...]

For testing I used the kernel .config from 5.15.32 for 5.16.18 via make oldconfig and selecting =n for all questions.

Signature · 4 lines

You may reply to this email to add a comment.

You are receiving this mail because:
You are watching the assignee of the bug.

[email protected]

author

2022-03-30 22:55 UTC #1 lore raw

[Bug 215781] Highmem support broken on kernels greater 5.15.x on ppc32?

https://bugzilla.kernel.org/show_bug.cgi?id=215781

--- Comment #1 from Erhard F. ([email protected]) --- Created attachment 300665
--> https://bugzilla.kernel.org/attachment.cgi?id=300665&action=edit
dmesg (5.15.32, PowerMac G4 DP)

Signature · 4 lines

You may reply to this email to add a comment.

You are receiving this mail because:
You are watching the assignee of the bug.

[email protected]

author

2022-03-30 22:56 UTC #2 lore raw

[Bug 215781] Highmem support broken on kernels greater 5.15.x on ppc32?

In reply to [email protected]

https://bugzilla.kernel.org/show_bug.cgi?id=215781

--- Comment #2 from Erhard F. ([email protected]) --- Created attachment 300666
--> https://bugzilla.kernel.org/attachment.cgi?id=300666&action=edit
kernel .config (5.16.18, PowerMac G4 DP)

Signature · 4 lines

You may reply to this email to add a comment.

You are receiving this mail because:
You are watching the assignee of the bug.

[email protected]

author

2022-03-30 22:56 UTC #3 lore raw

[Bug 215781] Highmem support broken on kernels greater 5.15.x on ppc32?

In reply to [email protected]

https://bugzilla.kernel.org/show_bug.cgi?id=215781

--- Comment #3 from Erhard F. ([email protected]) --- Created attachment 300667
--> https://bugzilla.kernel.org/attachment.cgi?id=300667&action=edit
kernel .config (5.15.32, PowerMac G4 DP)

Signature · 4 lines

You may reply to this email to add a comment.

You are receiving this mail because:
You are watching the assignee of the bug.

[email protected]

author

2022-03-31 06:22 UTC #4 lore raw

[Bug 215781] Highmem support broken on kernels greater 5.15.x on ppc32?

In reply to [email protected]

https://bugzilla.kernel.org/show_bug.cgi?id=215781

--- Comment #4 from Christophe Leroy ([email protected]) --- This problem was introduced in 5.15 by commit 602946ec2f90 ("powerpc: Set max_mapnr correctly")

A similar issue has been opened at
https://github.com/linuxppc/issues/issues/399

Following series should fix it:
https://patchwork.ozlabs.org/project/linuxppc-dev/list/?state=*&series=286464

Signature · 4 lines

You may reply to this email to add a comment.

You are receiving this mail because:
You are watching the assignee of the bug.

[email protected]

author

2022-04-18 10:50 UTC #5 lore raw

[Bug 215781] Highmem support broken on kernels greater 5.15.x on ppc32?

In reply to [email protected]

https://bugzilla.kernel.org/show_bug.cgi?id=215781

--- Comment #5 from Erhard F. ([email protected]) --- Created attachment 300769
--> https://bugzilla.kernel.org/attachment.cgi?id=300769&action=edit
dmesg (5.18-rc3, PowerMac G4 DP)

Meanwhile the fixes landed in 5.16.x, 5.17.x and 5.18-rc3 is also ok. Thanks!

Signature · 4 lines

You may reply to this email to add a comment.

You are receiving this mail because:
You are watching the assignee of the bug.

[email protected]

author

2022-04-18 10:51 UTC #6 lore raw

[Bug 215781] Highmem support broken on kernels greater 5.15.x on ppc32?

In reply to [email protected]

https://bugzilla.kernel.org/show_bug.cgi?id=215781

Erhard F. ([email protected]) changed:

What |Removed |Added
----------------------------------------------------------------------------

             Status|NEW                         |RESOLVED
         Resolution|---                         |CODE_FIX

Signature · 4 lines

You may reply to this email to add a comment.

You are receiving this mail because:
You are watching the assignee of the bug.