kernel_optimize_test/arch/sparc
Mike Rapoport 4360dfa99f sparc32: register memory occupied by kernel as memblock.memory
sparc32 never registered the memory occupied by the kernel image with
memblock_add() and it only reserved this memory with meblock_reserve().

With openbios as system firmware, the memory occupied by the kernel is
reserved in openbios and removed from mem.available.  The prom setup code
in the kernel uses mem.available to set up the memory banks and
essentially there is a hole for the memory occupied by the kernel image.

Later in bootmem_init() this memory is memblock_reserve()d.

Up until recently, memmap initialization would call __init_single_page()
for the pages in that hole, the free_low_memory_core_early() would mark
them as reserved and everything would be Ok.

After the change in memmap initialization introduced by the commit "mm:
memmap_init: iterate over memblock regions rather that check each PFN",
the hole is skipped and the page structs for it are not initialized.  And
when they are passed from memblock to page allocator as reserved, the
latter gets confused.

Simply registering the memory occupied by the kernel with memblock_add()
resolves this issue.

Tested on qemu-system-sparc with Debian Etch [1] userspace.

[1] https://people.debian.org/~aurel32/qemu/sparc/debian_etch_sparc_small.qcow2

Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: David S. Miller <davem@davemloft.net>
Cc: Guenter Roeck <linux@roeck-us.net>
Link: https://lkml.kernel.org/r/20200517000050.GA87467@roeck-us.nlllllet/
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-03 20:09:49 -07:00
..
boot .gitignore: add SPDX License Identifier 2020-03-25 11:50:48 +01:00
configs scsi: sr: remove references to BLK_DEV_SR_VENDOR, leave it enabled 2020-02-24 14:59:01 -05:00
crypto crypto: lib/sha1 - remove unnecessary includes of linux/cryptohash.h 2020-05-08 15:32:17 +10:00
include mm/hugetlb: define a generic fallback for arch_clear_hugepage_flags() 2020-06-03 20:09:46 -07:00
kernel vfs: add faccessat2 syscall 2020-05-14 16:44:25 +02:00
lib sparc64: Add missing newline at end of file 2019-07-09 14:53:57 -07:00
math-emu treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
mm sparc32: register memory occupied by kernel as memblock.memory 2020-06-03 20:09:49 -07:00
net treewide: Use sizeof_field() macro 2019-12-09 10:36:44 -08:00
oprofile treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
power treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
prom
vdso sparc,x86: vdso: remove meaningless undefining CONFIG_OPTIMIZE_INLINING 2020-04-07 10:43:42 -07:00
Kbuild treewide: Add SPDX license identifier - Kbuild 2019-05-30 11:32:33 -07:00
Kconfig mm: remove early_pfn_in_nid() and CONFIG_NODES_SPAN_OTHER_NODES 2020-06-03 20:09:44 -07:00
Kconfig.debug Kconfig: consolidate the "Kernel hacking" menu 2018-08-02 08:06:48 +09:00
Makefile sparc: generate uapi header and system call table files 2018-11-18 18:52:22 -08:00