kernel/Documentation/sysctl, branch linux-4.16.y

Documentation/sysctl/user.txt: fix typo

2018-02-07T02:32:48Z

Fix 'documetation' to 'documentation' Link: http://lkml.kernel.org/r/CAKW4uUxRPZz59aWAX8ytaCB5=Qh6d_CvAnO7rYq-6NRAnQJbDA@mail.gmail.com Signed-off-by: Kangmin Park Reviewed-by: Andrew Morton Cc: Jiri Kosina Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Merge tag 'docs-4.16' of git://git.lwn.net/linux

2018-02-01T03:25:25Z

Pull documentation updates from Jonathan Corbet: "Documentation updates for 4.16. New stuff includes refcount_t documentation, errseq documentation, kernel-doc support for nested structure definitions, the removal of lots of crufty kernel-doc support for unused formats, SPDX tag documentation, the beginnings of a manual for subsystem maintainers, and lots of fixes and updates. As usual, some of the changesets reach outside of Documentation/ to effect kerneldoc comment fixes. It also adds the new LICENSES directory, of which Thomas promises I do not need to be the maintainer" * tag 'docs-4.16' of git://git.lwn.net/linux: (65 commits) linux-next: docs-rst: Fix typos in kfigure.py linux-next: DOC: HWPOISON: Fix path to debugfs in hwpoison.txt Documentation: Fix misconversion of #if docs: add index entry for networking/msg_zerocopy Documentation: security/credentials.rst: explain need to sort group_list LICENSES: Add MPL-1.1 license LICENSES: Add the GPL 1.0 license LICENSES: Add Linux syscall note exception LICENSES: Add the MIT license LICENSES: Add the BSD-3-clause "Clear" license LICENSES: Add the BSD 3-clause "New" or "Revised" License LICENSES: Add the BSD 2-clause "Simplified" license LICENSES: Add the LGPL-2.1 license LICENSES: Add the LGPL 2.0 license LICENSES: Add the GPL 2.0 license Documentation: Add license-rules.rst to describe how to properly identify file licenses scripts: kernel_doc: better handle show warnings logic fs/*/Kconfig: drop links to 404-compliant http://acl.bestbits.at doc: md: Fix a file name to md-fault.c in fault-injection.txt errseq: Add to documentation tree ...

Merge branch 'akpm' (patches from Andrew)

2018-02-01T02:46:22Z

Merge updates from Andrew Morton: - misc fixes - ocfs2 updates - most of MM * emailed patches from Andrew Morton : (118 commits) mm: remove PG_highmem description tools, vm: new option to specify kpageflags file mm/swap.c: make functions and their kernel-doc agree mm, memory_hotplug: fix memmap initialization mm: correct comments regarding do_fault_around() mm: numa: do not trap faults on shared data section pages. hugetlb, mbind: fall back to default policy if vma is NULL hugetlb, mempolicy: fix the mbind hugetlb migration mm, hugetlb: further simplify hugetlb allocation API mm, hugetlb: get rid of surplus page accounting tricks mm, hugetlb: do not rely on overcommit limit during migration mm, hugetlb: integrate giga hugetlb more naturally to the allocation path mm, hugetlb: unify core page allocation accounting and initialization mm/memcontrol.c: try harder to decrease [memory,memsw].limit_in_bytes mm/memcontrol.c: make local symbol static mm/hmm: fix uninitialized use of 'entry' in hmm_vma_walk_pmd() include/linux/mmzone.h: fix explanation of lower bits in the SPARSEMEM mem_map pointer mm/compaction.c: fix comment for try_to_compact_pages() mm/page_ext.c: make page_ext_init a noop when CONFIG_PAGE_EXTENSION but nothing uses it zsmalloc: use U suffix for negative literals being shifted ...

mm, hugetlb: remove hugepages_treat_as_movable sysctl

2018-02-01T01:18:37Z

hugepages_treat_as_movable has been introduced by 396faf0303d2 ("Allow huge page allocations to use GFP_HIGH_MOVABLE") to allow hugetlb allocations from ZONE_MOVABLE even when hugetlb pages were not migrateable. The purpose of the movable zone was different at the time. It aimed at reducing memory fragmentation and hugetlb pages being long lived and large werre not contributing to the fragmentation so it was acceptable to use the zone back then. Things have changed though and the primary purpose of the zone became migratability guarantee. If we allow non migrateable hugetlb pages to be in ZONE_MOVABLE memory hotplug might fail to offline the memory. Remove the knob and only rely on hugepage_migration_supported to allow movable zones. Mel said: : Primarily it was aimed at allowing the hugetlb pool to safely shrink with : the ability to grow it again. The use case was for batched jobs, some of : which needed huge pages and others that did not but didn't want the memory : useless pinned in the huge pages pool. : : I suspect that more users rely on THP than hugetlbfs for flexible use of : huge pages with fallback options so I think that removing the option : should be ok. Link: http://lkml.kernel.org/r/20171003072619.8654-1-mhocko@kernel.org Signed-off-by: Michal Hocko Reported-by: Alexandru Moise <00moses.alexander00@gmail.com> Acked-by: Mel Gorman Cc: Alexandru Moise <00moses.alexander00@gmail.com> Cc: Mike Kravetz Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

doc: update kptr_restrict documentation

2017-12-21T20:39:27Z

Recently the behaviour of printk specifier %pK was changed. The documentation does not currently mirror this. Update documentation for sysctl kptr_restrict. Signed-off-by: Tobin C. Harding Signed-off-by: Jonathan Corbet

net: Clarify dev_weight documentation for LRO and GRO_HW.

2017-12-20T18:04:01Z

Reported-by: Marcelo Ricardo Leitner Signed-off-by: Michael Chan Signed-off-by: David S. Miller

Documentation: Better document the hardlockup_panic sysctl

2017-12-11T21:55:29Z

Commit ac1f591249d95372f ("kernel/watchdog.c: add sysctl knob hardlockup_panic") added the hardlockup_panic sysctl, but did not add it to Documentation/sysctl/kernel.txt. Add this, and reference it from the corresponding entry in Documentation/admin-guide/kernel-parameters.txt. Signed-off-by: Scott Wood Acked-by: Christoph von Recklinghausen Acked-by: Don Zickus Signed-off-by: Jonathan Corbet

Revert "mm/page-writeback.c: print a warning if the vm dirtiness settings are illogical"

2017-11-30T02:40:43Z

This reverts commit 0f6d24f87856 ("mm/page-writeback.c: print a warning if the vm dirtiness settings are illogical") because it causes false positive warnings during OOM situations as noticed by Tetsuo Handa: Node 0 active_anon:3525940kB inactive_anon:8372kB active_file:216kB inactive_file:1872kB unevictable:0kB isolated(anon):0kB isolated(file):0kB mapped:2504kB dirty:52kB writeback:0kB shmem:8660kB shmem_thp: 0kB shmem_pmdmapped: 0kB anon_thp: 636928kB writeback_tmp:0kB unstable:0kB all_unreclaimable? yes Node 0 DMA free:14848kB min:284kB low:352kB high:420kB active_anon:992kB inactive_anon:0kB active_file:0kB inactive_file:0kB unevictable:0kB writepending:0kB present:15988kB managed:15904kB mlocked:0kB kernel_stack:0kB pagetables:24kB bounce:0kB free_pcp:0kB local_pcp:0kB free_cma:0kB lowmem_reserve[]: 0 2687 3645 3645 Node 0 DMA32 free:53004kB min:49608kB low:62008kB high:74408kB active_anon:2712648kB inactive_anon:0kB active_file:0kB inactive_file:0kB unevictable:0kB writepending:0kB present:3129216kB managed:2773132kB mlocked:0kB kernel_stack:96kB pagetables:5096kB bounce:0kB free_pcp:0kB local_pcp:0kB free_cma:0kB lowmem_reserve[]: 0 0 958 958 Node 0 Normal free:17140kB min:17684kB low:22104kB high:26524kB active_anon:812300kB inactive_anon:8372kB active_file:1228kB inactive_file:1868kB unevictable:0kB writepending:52kB present:1048576kB managed:981224kB mlocked:0kB kernel_stack:3520kB pagetables:8552kB bounce:0kB free_pcp:120kB local_pcp:120kB free_cma:0kB lowmem_reserve[]: 0 0 0 0 [...] Out of memory: Kill process 8459 (a.out) score 999 or sacrifice child Killed process 8459 (a.out) total-vm:4180kB, anon-rss:88kB, file-rss:0kB, shmem-rss:0kB oom_reaper: reaped process 8459 (a.out), now anon-rss:0kB, file-rss:0kB, shmem-rss:0kB vm direct limit must be set greater than background limit. The problem is that both thresh and bg_thresh will be 0 if available_memory is less than 4 pages when evaluating global_dirtyable_memory. While this might be worked around the whole point of the warning is dubious at best. We do rely on admins to do sensible things when changing tunable knobs. Dirty memory writeback knobs are not any special in that regards so revert the warning rather than adding more hacks to work this around. Debugged by Yafang Shao. Link: http://lkml.kernel.org/r/20171127091939.tahb77nznytcxw55@dhcp22.suse.cz Fixes: 0f6d24f87856 ("mm/page-writeback.c: print a warning if the vm dirtiness settings are illogical") Signed-off-by: Michal Hocko Reported-by: Tetsuo Handa Cc: Yafang Shao Cc: Jan Kara Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Documentation/sysctl/vm.txt: fix typo

2017-11-18T00:10:03Z

Link: http://lkml.kernel.org/r/CAKW4uUyCi=PnKf3epgFVz8z=1tMtHSOHNm+fdNxrNw3-THvRCA@mail.gmail.com Signed-off-by: Kangmin Park Cc: Jiri Kosina Cc: Alan Cox Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm, sysctl: make NUMA stats configurable

2017-11-16T02:21:07Z

This is the second step which introduces a tunable interface that allow numa stats configurable for optimizing zone_statistics(), as suggested by Dave Hansen and Ying Huang. ========================================================================= When page allocation performance becomes a bottleneck and you can tolerate some possible tool breakage and decreased numa counter precision, you can do: echo 0 > /proc/sys/vm/numa_stat In this case, numa counter update is ignored. We can see about *4.8%*(185->176) drop of cpu cycles per single page allocation and reclaim on Jesper's page_bench01 (single thread) and *8.1%*(343->315) drop of cpu cycles per single page allocation and reclaim on Jesper's page_bench03 (88 threads) running on a 2-Socket Broadwell-based server (88 threads, 126G memory). Benchmark link provided by Jesper D Brouer (increase loop times to 10000000): https://github.com/netoptimizer/prototype-kernel/tree/master/kernel/mm/bench ========================================================================= When page allocation performance is not a bottleneck and you want all tooling to work, you can do: echo 1 > /proc/sys/vm/numa_stat This is system default setting. Many thanks to Michal Hocko, Dave Hansen, Ying Huang and Vlastimil Babka for comments to help improve the original patch. [keescook@chromium.org: make sure mutex is a global static] Link: http://lkml.kernel.org/r/20171107213809.GA4314@beast Link: http://lkml.kernel.org/r/1508290927-8518-1-git-send-email-kemi.wang@intel.com Signed-off-by: Kemi Wang Signed-off-by: Kees Cook Reported-by: Jesper Dangaard Brouer Suggested-by: Dave Hansen Suggested-by: Ying Huang Acked-by: Vlastimil Babka Acked-by: Michal Hocko Cc: "Luis R . Rodriguez" Cc: Kees Cook Cc: Jonathan Corbet Cc: Mel Gorman Cc: Johannes Weiner Cc: Christopher Lameter Cc: Sebastian Andrzej Siewior Cc: Andrey Ryabinin Cc: Tim Chen Cc: Andi Kleen Cc: Aaron Lu Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds