The commit 1c30844d2d ("mm: reclaim small amounts of memory when an
external fragmentation event occurs") breaks memory management on a
parisc c8000 workstation with this memory layout:
0) Start 0x0000000000000000 End 0x000000003fffffff Size 1024 MB
1) Start 0x0000000100000000 End 0x00000001bfdfffff Size 3070 MB
2) Start 0x0000004040000000 End 0x00000040ffffffff Size 3072 MB
With the patch 1c30844d2d, the kernel will incorrectly reclaim the
first zone when it fills up, ignoring the fact that there are two
completely free zones. Basiscally, it limits cache size to 1GiB.
The parisc kernel is currently using the DISCONTIGMEM implementation,
but isn't NUMA. Avoid this issue or strange work-arounds by switching to
the more commonly used SPARSEMEM implementation.
Reported-by: Mikulas Patocka <mpatocka@redhat.com>
Fixes: 1c30844d2d ("mm: reclaim small amounts of memory when an external fragmentation event occurs")
Signed-off-by: Helge Deller <deller@gmx.de>
(cherry picked from commit dbdf076099)
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: Icea3d5728ab2a218c4f6aa14b2c89984bba484dd
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.
See Documentation/00-INDEX for a list of what is contained in each file.
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.
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