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.
Linxu Fang
authored
342332e6 ("mm/page_alloc.c: introduce kernelcore=mirror option") and later patches rewrote the calculation of node spanned pages. e506b996 ("mem-hotplug: fix node spanned pages when we have a movable node"), but the current code still has problems, When we have a node with only zone_movable and the node id is not zero, the size of node spanned pages is double added. That's because we have an empty normal zone, and zone_start_pfn or zone_end_pfn is not between arch_zone_lowest_possible_pfn and arch_zone_highest_possible_pfn, so we need to use clamp to constrain the range just like the commit <96e907d1> (bootmem: Reimplement __absent_pages_in_range() using for_each_mem_pfn_range()). e.g. Zone ranges: DMA [mem 0x0000000000001000-0x0000000000ffffff] DMA32 [mem 0x0000000001000000-0x00000000ffffffff] Normal [mem 0x0000000100000000-0x000000023fffffff] Movable zone start for each node Node 0: 0x0000000100000000 Node 1: 0x0000000140000000 Early memory node ranges node 0: [mem 0x0000000000001000-0x000000000009efff] node 0: [mem 0x0000000000100000-0x00000000bffdffff] node 0: [mem 0x0000000100000000-0x000000013fffffff] node 1: [mem 0x0000000140000000-0x000000023fffffff] node 0 DMA spanned:0xfff present:0xf9e absent:0x61 node 0 DMA32 spanned:0xff000 present:0xbefe0 absent:0x40020 node 0 Normal spanned:0 present:0 absent:0 node 0 Movable spanned:0x40000 present:0x40000 absent:0 On node 0 totalpages(node_present_pages): 1048446 node_spanned_pages:1310719 node 1 DMA spanned:0 present:0 absent:0 node 1 DMA32 spanned:0 present:0 absent:0 node 1 Normal spanned:0x100000 present:0x100000 absent:0 node 1 Movable spanned:0x100000 present:0x100000 absent:0 On node 1 totalpages(node_present_pages): 2097152 node_spanned_pages:2097152 Memory: 6967796K/12582392K available (16388K kernel code, 3686K rwdata, 4468K rodata, 2160K init, 10444K bss, 5614596K reserved, 0K cma-reserved) It shows that the current memory of node 1 is double added. After this patch, the problem is fixed. node 0 DMA spanned:0xfff present:0xf9e absent:0x61 node 0 DMA32 spanned:0xff000 present:0xbefe0 absent:0x40020 node 0 Normal spanned:0 present:0 absent:0 node 0 Movable spanned:0x40000 present:0x40000 absent:0 On node 0 totalpages(node_present_pages): 1048446 node_spanned_pages:1310719 node 1 DMA spanned:0 present:0 absent:0 node 1 DMA32 spanned:0 present:0 absent:0 node 1 Normal spanned:0 present:0 absent:0 node 1 Movable spanned:0x100000 present:0x100000 absent:0 On node 1 totalpages(node_present_pages): 1048576 node_spanned_pages:1048576 memory: 6967796K/8388088K available (16388K kernel code, 3686K rwdata, 4468K rodata, 2160K init, 10444K bss, 1420292K reserved, 0K cma-reserved) Link: http://lkml.kernel.org/r/1554178276-10372-1-git-send-email-fanglinxu@huawei.com Signed-off-by:Linxu Fang <fanglinxu@huawei.com> Cc: Taku Izumi <izumi.taku@jp.fujitsu.com> Cc: Xishi Qiu <qiuxishi@huawei.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Pavel Tatashin <pavel.tatashin@microsoft.com> Cc: Oscar Salvador <osalvador@suse.de> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
| Name | Last commit | Last update |
|---|---|---|
| Documentation | ||
| LICENSES | ||
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README |