It is enough to use a file name to cross-reference another rst document.
Jon says:
The right things will happen in the HTML output, readers of the
plain-text will know immediately where to go, and we don't have to add
the label clutter.
Drop reference markup and unnecessary labels and use plain file names.
Signed-off-by: Mike Rapoport (IBM) <rppt@kernel.org>
Link: https://lore.kernel.org/r/20230201094156.991542-4-rppt@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Pull MM updates from Andrew Morton:
- More userfaultfs work from Peter Xu
- Several convert-to-folios series from Sidhartha Kumar and Huang Ying
- Some filemap cleanups from Vishal Moola
- David Hildenbrand added the ability to selftest anon memory COW
handling
- Some cpuset simplifications from Liu Shixin
- Addition of vmalloc tracing support by Uladzislau Rezki
- Some pagecache folioifications and simplifications from Matthew
Wilcox
- A pagemap cleanup from Kefeng Wang: we have VM_ACCESS_FLAGS, so use
it
- Miguel Ojeda contributed some cleanups for our use of the
__no_sanitize_thread__ gcc keyword.
This series should have been in the non-MM tree, my bad
- Naoya Horiguchi improved the interaction between memory poisoning and
memory section removal for huge pages
- DAMON cleanups and tuneups from SeongJae Park
- Tony Luck fixed the handling of COW faults against poisoned pages
- Peter Xu utilized the PTE marker code for handling swapin errors
- Hugh Dickins reworked compound page mapcount handling, simplifying it
and making it more efficient
- Removal of the autonuma savedwrite infrastructure from Nadav Amit and
David Hildenbrand
- zram support for multiple compression streams from Sergey Senozhatsky
- David Hildenbrand reworked the GUP code's R/O long-term pinning so
that drivers no longer need to use the FOLL_FORCE workaround which
didn't work very well anyway
- Mel Gorman altered the page allocator so that local IRQs can remnain
enabled during per-cpu page allocations
- Vishal Moola removed the try_to_release_page() wrapper
- Stefan Roesch added some per-BDI sysfs tunables which are used to
prevent network block devices from dirtying excessive amounts of
pagecache
- David Hildenbrand did some cleanup and repair work on KSM COW
breaking
- Nhat Pham and Johannes Weiner have implemented writeback in zswap's
zsmalloc backend
- Brian Foster has fixed a longstanding corner-case oddity in
file[map]_write_and_wait_range()
- sparse-vmemmap changes for MIPS, LoongArch and NIOS2 from Feiyang
Chen
- Shiyang Ruan has done some work on fsdax, to make its reflink mode
work better under xfstests. Better, but still not perfect
- Christoph Hellwig has removed the .writepage() method from several
filesystems. They only need .writepages()
- Yosry Ahmed wrote a series which fixes the memcg reclaim target
beancounting
- David Hildenbrand has fixed some of our MM selftests for 32-bit
machines
- Many singleton patches, as usual
* tag 'mm-stable-2022-12-13' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (313 commits)
mm/hugetlb: set head flag before setting compound_order in __prep_compound_gigantic_folio
mm: mmu_gather: allow more than one batch of delayed rmaps
mm: fix typo in struct pglist_data code comment
kmsan: fix memcpy tests
mm: add cond_resched() in swapin_walk_pmd_entry()
mm: do not show fs mm pc for VM_LOCKONFAULT pages
selftests/vm: ksm_functional_tests: fixes for 32bit
selftests/vm: cow: fix compile warning on 32bit
selftests/vm: madv_populate: fix missing MADV_POPULATE_(READ|WRITE) definitions
mm/gup_test: fix PIN_LONGTERM_TEST_READ with highmem
mm,thp,rmap: fix races between updates of subpages_mapcount
mm: memcg: fix swapcached stat accounting
mm: add nodes= arg to memory.reclaim
mm: disable top-tier fallback to reclaim on proactive reclaim
selftests: cgroup: make sure reclaim target memcg is unprotected
selftests: cgroup: refactor proactive reclaim code to reclaim_until()
mm: memcg: fix stale protection of reclaim target memcg
mm/mmap: properly unaccount memory on mas_preallocate() failure
omfs: remove ->writepage
jfs: remove ->writepage
...
DAMON debugfs interface assumes the users will write all inputs at once.
However, redirecting a string of multiple lines sometimes end up writing
line by line. Therefore, the example usage of 'init_regions' file, which
writes input as a string of multiple lines can fail. Fix it to use a
single line string instead. Also update the description of the usage to
not assume users will write inputs in multiple lines.
Link: https://lkml.kernel.org/r/20221024174619.15600-3-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Vinicius Petrucci <vpetrucci@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Pull MM updates from Andrew Morton:
- Yu Zhao's Multi-Gen LRU patches are here. They've been under test in
linux-next for a couple of months without, to my knowledge, any
negative reports (or any positive ones, come to that).
- Also the Maple Tree from Liam Howlett. An overlapping range-based
tree for vmas. It it apparently slightly more efficient in its own
right, but is mainly targeted at enabling work to reduce mmap_lock
contention.
Liam has identified a number of other tree users in the kernel which
could be beneficially onverted to mapletrees.
Yu Zhao has identified a hard-to-hit but "easy to fix" lockdep splat
at [1]. This has yet to be addressed due to Liam's unfortunately
timed vacation. He is now back and we'll get this fixed up.
- Dmitry Vyukov introduces KMSAN: the Kernel Memory Sanitizer. It uses
clang-generated instrumentation to detect used-unintialized bugs down
to the single bit level.
KMSAN keeps finding bugs. New ones, as well as the legacy ones.
- Yang Shi adds a userspace mechanism (madvise) to induce a collapse of
memory into THPs.
- Zach O'Keefe has expanded Yang Shi's madvise(MADV_COLLAPSE) to
support file/shmem-backed pages.
- userfaultfd updates from Axel Rasmussen
- zsmalloc cleanups from Alexey Romanov
- cleanups from Miaohe Lin: vmscan, hugetlb_cgroup, hugetlb and
memory-failure
- Huang Ying adds enhancements to NUMA balancing memory tiering mode's
page promotion, with a new way of detecting hot pages.
- memcg updates from Shakeel Butt: charging optimizations and reduced
memory consumption.
- memcg cleanups from Kairui Song.
- memcg fixes and cleanups from Johannes Weiner.
- Vishal Moola provides more folio conversions
- Zhang Yi removed ll_rw_block() :(
- migration enhancements from Peter Xu
- migration error-path bugfixes from Huang Ying
- Aneesh Kumar added ability for a device driver to alter the memory
tiering promotion paths. For optimizations by PMEM drivers, DRM
drivers, etc.
- vma merging improvements from Jakub Matěn.
- NUMA hinting cleanups from David Hildenbrand.
- xu xin added aditional userspace visibility into KSM merging
activity.
- THP & KSM code consolidation from Qi Zheng.
- more folio work from Matthew Wilcox.
- KASAN updates from Andrey Konovalov.
- DAMON cleanups from Kaixu Xia.
- DAMON work from SeongJae Park: fixes, cleanups.
- hugetlb sysfs cleanups from Muchun Song.
- Mike Kravetz fixes locking issues in hugetlbfs and in hugetlb core.
Link: https://lkml.kernel.org/r/CAOUHufZabH85CeUN-MEMgL8gJGzJEWUrkiM58JkTbBhh-jew0Q@mail.gmail.com [1]
* tag 'mm-stable-2022-10-08' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (555 commits)
hugetlb: allocate vma lock for all sharable vmas
hugetlb: take hugetlb vma_lock when clearing vma_lock->vma pointer
hugetlb: fix vma lock handling during split vma and range unmapping
mglru: mm/vmscan.c: fix imprecise comments
mm/mglru: don't sync disk for each aging cycle
mm: memcontrol: drop dead CONFIG_MEMCG_SWAP config symbol
mm: memcontrol: use do_memsw_account() in a few more places
mm: memcontrol: deprecate swapaccounting=0 mode
mm: memcontrol: don't allocate cgroup swap arrays when memcg is disabled
mm/secretmem: remove reduntant return value
mm/hugetlb: add available_huge_pages() func
mm: remove unused inline functions from include/linux/mm_inline.h
selftests/vm: add selftest for MADV_COLLAPSE of uffd-minor memory
selftests/vm: add file/shmem MADV_COLLAPSE selftest for cleared pmd
selftests/vm: add thp collapse shmem testing
selftests/vm: add thp collapse file and tmpfs testing
selftests/vm: modularize thp collapse memory operations
selftests/vm: dedup THP helpers
mm/khugepaged: add tracepoint to hpage_collapse_scan_file()
mm/madvise: add file and shmem support to MADV_COLLAPSE
...
The main benefit of THPs are that they can be mapped at the pmd level,
increasing the likelihood of TLB hit and spending less cycles in page
table walks. pte-mapped hugepages - that is - hugepage-aligned compound
pages of order HPAGE_PMD_ORDER mapped by ptes - although being contiguous
in physical memory, don't have this advantage. In fact, one could argue
they are detrimental to system performance overall since they occupy a
precious hugepage-aligned/sized region of physical memory that could
otherwise be used more effectively. Additionally, pte-mapped hugepages
can be the cheapest memory to collapse for khugepaged since no new
hugepage allocation or copying of memory contents is necessary - we only
need to update the mapping page tables.
In the anonymous collapse path, we are able to collapse pte-mapped
hugepages (albeit, perhaps suboptimally), but the file/shmem path makes no
effort when compound pages (of any order) are encountered.
Identify pte-mapped hugepages in the file/shmem collapse path. The
final step of which makes a racy check of the value of the pmd to
ensure it maps a pte table. This should be fine, since races that
result in false-positive (i.e. attempt collapse even though we
shouldn't) will fail later in collapse_pte_mapped_thp() once we
actually lock mmap_lock and reinspect the pmd value. Races that result
in false-negatives (i.e. where we decide to not attempt collapse, but
should have) shouldn't be an issue, since in the worst case, we do
nothing - which is what we've done up to this point. We make a similar
check in retract_page_tables(). If we do think we've found a
pte-mapped hugepgae in khugepaged context, attempt to update page
tables mapping this hugepage.
Note that these collapses still count towards the
/sys/kernel/mm/transparent_hugepage/khugepaged/pages_collapsed counter,
and if the pte-mapped hugepage was also mapped into multiple process'
address spaces, could be incremented for each page table update. Since we
increment the counter when a pte-mapped hugepage is successfully added to
the list of to-collapse pte-mapped THPs, it's possible that we never
actually update the page table either. This is different from how
file/shmem pages_collapsed accounting works today where only a successful
page cache update is counted (it's also possible here that no page tables
are actually changed). Though it incurs some slop, this is preferred to
either not accounting for the event at all, or plumbing through data in
struct mm_slot on whether to account for the collapse or not.
Also note that work still needs to be done to support arbitrary compound
pages, and that this should all be converted to using folios.
[shy828301@gmail.com: Spelling mistake, update comment, and add Documentation]
Link: https://lore.kernel.org/linux-mm/CAHbLzkpHwZxFzjfX9nxVoRhzup8WMjMfyL6Xiq8mZ9M-N3ombw@mail.gmail.com/
Link: https://lkml.kernel.org/r/20220907144521.3115321-3-zokeefe@google.com
Link: https://lkml.kernel.org/r/20220922224046.1143204-3-zokeefe@google.com
Signed-off-by: Zach O'Keefe <zokeefe@google.com>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Chris Kennelly <ckennelly@google.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: James Houghton <jthoughton@google.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Rongwei Wang <rongwei.wang@linux.alibaba.com>
Cc: SeongJae Park <sj@kernel.org>
Cc: Song Liu <songliubraving@fb.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
'Getting Started' document of DAMON says DAMON user-space tool, damo[1],
is using DAMON debugfs interface, and therefore it needs to ensure debugfs
is mounted. However, the latest version of the tool is using DAMON sysfs
interface. Moreover, DAMON debugfs interface is going to be deprecated as
announced by commit b18402726b ("Docs/admin-guide/mm/damon/usage:
document DAMON sysfs interface").
This commit therefore update the document to tell readers about DAMON
sysfs interface dependency instead and never mention about debugfs
interface, which will be deprecated.
[1] https://github.com/awslabs/damo
Link: https://lkml.kernel.org/r/20220909202901.57977-7-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Brendan Higgins <brendanhiggins@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Yun Levi <ppbuk5246@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The title of the DAMON document for admin-guide, 'Monitoring Data
Accesses', could confuse readers in some ways. First of all, DAMON is not
the only single way for data access monitoring. And the document is for
not only the data access monitoring but also data access pattern based
memory management optimizations (DAMOS). This commit updates the title to
'DAMON: Data Access MONitor', which more explicitly explains what the
document describes.
Link: https://lkml.kernel.org/r/20220909202901.57977-5-sj@kernel.org
Fixes: c4ba6014ae ("Documentation: add documents for DAMON")
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Brendan Higgins <brendanhiggins@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Yun Levi <ppbuk5246@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Pull documentation updates from Jonathan Corbet:
"There's not a huge amount of activity in the docs tree this time
around, but a few significant changes even so:
- A complete rewriting of the top-level index.rst file, which mostly
reflects itself in a redone top page in the HTML-rendered docs. The
hope is that the new organization will be a friendlier starting
point for both users and developers.
- Some math-rendering improvements.
- A coding-style.rst update on the use of BUG() and WARN()
- A big maintainer-PHP guide update.
- Some code-of-conduct updates
- More Chinese translation work
Plus the usual pile of typo fixes, corrections, and updates"
* tag 'docs-6.1' of git://git.lwn.net/linux: (66 commits)
checkpatch: warn on usage of VM_BUG_ON() and other BUG variants
coding-style.rst: document BUG() and WARN() rules ("do not crash the kernel")
Documentation: devres: add missing IO helper
Documentation: devres: update IRQ helper
Documentation/mm: modify page_referenced to folio_referenced
Documentation/CoC: Reflect current CoC interpretation and practices
docs/doc-guide: Add documentation on SPHINX_IMGMATH
docs: process/5.Posting.rst: clarify use of Reported-by: tag
docs, kprobes: Fix the wrong location of Kprobes
docs: add a man-pages link to the front page
docs: put atomic*.txt and memory-barriers.txt into the core-api book
docs: move asm-annotations.rst into core-api
docs: remove some index.rst cruft
docs: reconfigure the HTML left column
docs: Rewrite the front page
docs: promote the title of process/index.rst
Documentation: devres: add missing SPI helper
Documentation: devres: add missing PINCTRL helpers
docs: hugetlbpage.rst: fix a typo of hugepage size
docs/zh_CN: Add new translation of admin-guide/bootconfig.rst
...
Currently only 12 characters of the cma name is being used as the debug
directories where as the cma name can be of length CMA_MAX_NAME(=64)
characters. One side problem with this is having 2 cma's with first
common 12 characters would end up in trying to create directories with
same name and fails with -EEXIST thus can limit cma debug functionality.
The 'cma-' prefix is used initially where cma areas don't have any names
and are represented by simple integer values. Since now each cma would be
having its own name, drop 'cma-' prefix for the cma debug directories as
they are clearly evident that they are for cma debug through creating them
in /sys/kernel/debug/cma/ path.
Link: https://lkml.kernel.org/r/1660223729-22461-1-git-send-email-quic_charante@quicinc.com
Signed-off-by: Charan Teja Kalla <quic_charante@quicinc.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Pavan Kondeti <quic_pkondeti@quicinc.com>
Cc: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "mm/damon: trivial cleanups".
This patchset contains trivial cleansups for DAMON code.
This patch (of 6):
Commit 81a84182c3 ("Docs/admin-guide/mm/damon/reclaim: document
'commit_inputs' parameter") has documented the 'commit_inputs' parameter
which allows online parameter update, but it didn't remove a paragraph
saying the online parameter update is impossible. This commit removes the
obsolete paragraph.
Link: https://lkml.kernel.org/r/20220606182310.48781-1-sj@kernel.org
Link: https://lkml.kernel.org/r/20220606182310.48781-2-sj@kernel.org
Fixes: 81a84182c3 ("Docs/admin-guide/mm/damon/reclaim: document 'commit_inputs' parameter")
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
so it will be consistent with code mm directory and with
Documentation/admin-guide/mm and won't be confused with virtual machines.
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Suggested-by: Matthew Wilcox <willy@infradead.org>
Tested-by: Ira Weiny <ira.weiny@intel.com>
Acked-by: Jonathan Corbet <corbet@lwn.net>
Acked-by: Wu XiangCheng <bobwxc@email.cn>
