No description
  • C 98.2%
  • Assembly 1%
  • Makefile 0.3%
  • Shell 0.2%
  • Python 0.1%
Find a file
Repository files (latest commit first)
Filename Latest commit message Latest commit date
Song Liu 27e1f82731 khugepaged: enable collapse pmd for pte-mapped THP
khugepaged needs exclusive mmap_sem to access page table.  When it fails
to lock mmap_sem, the page will fault in as pte-mapped THP.  As the page
is already a THP, khugepaged will not handle this pmd again.

This patch enables the khugepaged to retry collapse the page table.

struct mm_slot (in khugepaged.c) is extended with an array, containing
addresses of pte-mapped THPs.  We use array here for simplicity.  We can
easily replace it with more advanced data structures when needed.

In khugepaged_scan_mm_slot(), if the mm contains pte-mapped THP, we try to
collapse the page table.

Since collapse may happen at an later time, some pages may already fault
in.  collapse_pte_mapped_thp() is added to properly handle these pages.
collapse_pte_mapped_thp() also double checks whether all ptes in this pmd
are mapping to the same THP.  This is necessary because some subpage of
the THP may be replaced, for example by uprobe.  In such cases, it is not
possible to collapse the pmd.

[kirill.shutemov@linux.intel.com: add comments for retract_page_tables()]
  Link: http://lkml.kernel.org/r/20190816145443.6ard3iilytc6jlgv@box
Link: http://lkml.kernel.org/r/20190815164525.1848545-6-songliubraving@fb.com
Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Suggested-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-24 15:54:11 -07:00
arch thp: update split_huge_page_pmd() comment 2019-09-24 15:54:10 -07:00
block
certs
crypto - crypto and DM crypt advances that allow the crypto API to reclaim 2019-09-21 10:40:37 -07:00
Documentation memcg, kmem: deprecate kmem.limit_in_bytes 2019-09-24 15:54:10 -07:00
drivers mm,thp: stats for file backed THP 2019-09-24 15:54:11 -07:00
fs mm,thp: avoid writes to file with THP in pagecache 2019-09-24 15:54:11 -07:00
include khugepaged: enable collapse pmd for pte-mapped THP 2019-09-24 15:54:11 -07:00
init mm: use CPU_BITS_NONE to initialize init_mm.cpu_bitmask 2019-09-24 15:54:10 -07:00
ipc
kernel uprobe: use FOLL_SPLIT_PMD instead of FOLL_SPLIT 2019-09-24 15:54:11 -07:00
lib mm: remove quicklist page table caches 2019-09-24 15:54:09 -07:00
LICENSES
mm khugepaged: enable collapse pmd for pte-mapped THP 2019-09-24 15:54:11 -07:00
net net/xdp: convert put_page() to put_user_page*() 2019-09-24 15:54:08 -07:00
samples rpmsg updates for v5.4 2019-09-22 10:58:15 -07:00
scripts Modules updates for v5.4 2019-09-22 10:34:46 -07:00
security
sound Main MIPS changes for v5.4: 2019-09-22 09:30:30 -07:00
tools f2fs-for-5.4-rc1 2019-09-21 14:26:33 -07:00
usr kbuild: clean compressed initramfs image 2019-09-24 15:54:07 -07:00
virt
.clang-format
.cocciconfig
.get_maintainer.ignore
.gitattributes
.gitignore Modules updates for v5.4 2019-09-22 10:34:46 -07:00
.mailmap
COPYING
CREDITS
Kbuild
Kconfig
MAINTAINERS power supply and reset changes for the v5.4 series 2019-09-22 12:04:59 -07:00
Makefile Modules updates for v5.4 2019-09-22 10:34:46 -07:00
README

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.