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Sergei Trofimovich 9df65f5225 mm: page_alloc: ignore init_on_free=1 for debug_pagealloc=1
On !ARCH_SUPPORTS_DEBUG_PAGEALLOC (like ia64) debug_pagealloc=1 implies
page_poison=on:

    if (page_poisoning_enabled() ||
         (!IS_ENABLED(CONFIG_ARCH_SUPPORTS_DEBUG_PAGEALLOC) &&
          debug_pagealloc_enabled()))
            static_branch_enable(&_page_poisoning_enabled);

page_poison=on needs to override init_on_free=1.

Before the change it did not work as expected for the following case:
- have PAGE_POISONING=y
- have page_poison unset
- have !ARCH_SUPPORTS_DEBUG_PAGEALLOC arch (like ia64)
- have init_on_free=1
- have debug_pagealloc=1

That way we get both keys enabled:
- static_branch_enable(&init_on_free);
- static_branch_enable(&_page_poisoning_enabled);

which leads to poisoned pages returned for __GFP_ZERO pages.

After the change we execute only:
- static_branch_enable(&_page_poisoning_enabled);
  and ignore init_on_free=1.

Link: https://lkml.kernel.org/r/20210329222555.3077928-1-slyfox@gentoo.org
Link: https://lkml.org/lkml/2021/3/26/443
Fixes: 8db26a3d47 ("mm, page_poison: use static key more efficiently")
Signed-off-by: Sergei Trofimovich <slyfox@gentoo.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-04-30 11:20:43 -07:00
arch mm: move mem_init_print_info() into mm_init() 2021-04-30 11:20:42 -07:00
block cgroup: rstat: punt root-level optimization to individual controllers 2021-04-30 11:20:37 -07:00
certs
crypto for-5.13/drivers-2021-04-27 2021-04-28 14:39:37 -07:00
Documentation mm/mempolicy: fix mpol_misplaced kernel-doc 2021-04-30 11:20:43 -07:00
drivers mm/vmalloc: remove unmap_kernel_range 2021-04-30 11:20:40 -07:00
fs Revert "mremap: don't allow MREMAP_DONTUNMAP on special_mappings and aio" 2021-04-30 11:20:39 -07:00
include net: page_pool: use alloc_pages_bulk in refill code path 2021-04-30 11:20:43 -07:00
init mm: move mem_init_print_info() into mm_init() 2021-04-30 11:20:42 -07:00
ipc
kernel irq_work: record irq_work_queue() call stack 2021-04-30 11:20:42 -07:00
lib kasan: detect false-positives in tests 2021-04-30 11:20:42 -07:00
LICENSES
mm mm: page_alloc: ignore init_on_free=1 for debug_pagealloc=1 2021-04-30 11:20:43 -07:00
net net: page_pool: use alloc_pages_bulk in refill code path 2021-04-30 11:20:43 -07:00
samples samples/vfio-mdev/mdpy: use remap_vmalloc_range 2021-04-30 11:20:39 -07:00
scripts scripts: a new script for checking duplicate struct declaration 2021-04-30 11:20:35 -07:00
security Networking changes for 5.13. 2021-04-29 11:57:23 -07:00
sound - Core Frameworks 2021-04-28 15:59:13 -07:00
tools vm/test_vmalloc.sh: adapt for updated driver interface 2021-04-30 11:20:40 -07:00
usr
virt
.clang-format
.cocciconfig
.get_maintainer.ignore
.gitattributes
.gitignore
.mailmap It's been a relatively busy cycle in docsland, though more than usually 2021-04-26 13:22:43 -07:00
COPYING
CREDITS - Core Frameworks 2021-04-28 15:59:13 -07:00
Kbuild
Kconfig
MAINTAINERS MAINTAINERS: assign pagewalk.h to MEMORY MANAGEMENT 2021-04-30 11:20:41 -07:00
Makefile Kconfig updates for v5.13 2021-04-29 14:32:00 -07:00
README

Linux kernel
============

There are several guides for kernel developers and users. These guides can
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In order to build the documentation, use ``make htmldocs`` or
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There are various text files in the Documentation/ subdirectory,
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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.