19d6242ece
When debugging with CONFIG_PAGE_OWNER, I noticed that the min_low_pfn on arm64 is always zero and the page owner scanning has to start from zero. We have to loop a while before we see the first valid pfn. (see: read_page_owner()) Setup min_low_pfn to save some loops. Before setting min_low_pfn: [ 21.265602] min_low_pfn=0, *ppos=0 Page allocated via order 0, mask 0x100cca(GFP_HIGHUSER_MOVABLE) PFN 262144 type Movable Block 512 type Movable Flags 0x8001e referenced|uptodate|dirty|lru|swapbacked) prep_new_page+0x13c/0x140 get_page_from_freelist+0x254/0x1068 __alloc_pages_nodemask+0xd4/0xcb8 After setting min_low_pfn: [ 11.025787] min_low_pfn=262144, *ppos=0 Page allocated via order 0, mask 0x100cca(GFP_HIGHUSER_MOVABLE) PFN 262144 type Movable Block 512 type Movable Flags 0x8001e referenced|uptodate|dirty|lru|swapbacked) prep_new_page+0x13c/0x140 get_page_from_freelist+0x254/0x1068 __alloc_pages_nodemask+0xd4/0xcb8 shmem_alloc_page+0x7c/0xa0 shmem_alloc_and_acct_page+0x124/0x1e8 shmem_getpage_gfp.isra.7+0x118/0x878 shmem_write_begin+0x38/0x68 Signed-off-by: Miles Chen <miles.chen@mediatek.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.