linux-dev/Documentation/admin-guide/sysctl, branch master

Merge tag 'mm-nonmm-stable-2022-10-11' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2022-10-12T18:00:22Z

Pull non-MM updates from Andrew Morton: - hfs and hfsplus kmap API modernization (Fabio Francesco) - make crash-kexec work properly when invoked from an NMI-time panic (Valentin Schneider) - ntfs bugfixes (Hawkins Jiawei) - improve IPC msg scalability by replacing atomic_t's with percpu counters (Jiebin Sun) - nilfs2 cleanups (Minghao Chi) - lots of other single patches all over the tree! * tag 'mm-nonmm-stable-2022-10-11' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (71 commits) include/linux/entry-common.h: remove has_signal comment of arch_do_signal_or_restart() prototype proc: test how it holds up with mapping'less process mailmap: update Frank Rowand email address ia64: mca: use strscpy() is more robust and safer init/Kconfig: fix unmet direct dependencies ia64: update config files nilfs2: replace WARN_ONs by nilfs_error for checkpoint acquisition failure fork: remove duplicate included header files init/main.c: remove unnecessary (void*) conversions proc: mark more files as permanent nilfs2: remove the unneeded result variable nilfs2: delete unnecessary checks before brelse() checkpatch: warn for non-standard fixes tag style usr/gen_init_cpio.c: remove unnecessary -1 values from int file ipc/msg: mitigate the lock contention with percpu counter percpu: add percpu_counter_add_local and percpu_counter_sub_local fs/ocfs2: fix repeated words in comments relay: use kvcalloc to alloc page array in relay_alloc_page_array proc: make config PROC_CHILDREN depend on PROC_FS fs: uninline inode_maybe_inc_iversion() ...

Merge tag 'mm-stable-2022-10-08' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2022-10-11T00:53:04Z

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 ...

bpf: Use bpf_capable() instead of CAP_SYS_ADMIN for blinding decision

2022-09-16T20:11:57Z

The full CAP_SYS_ADMIN requirement for blinding looks too strict nowadays. These days given unprivileged BPF is disabled by default, the main users for constant blinding coming from unprivileged in particular via cBPF -> eBPF migration (e.g. old-style socket filters). Signed-off-by: Yauheni Kaliuta Signed-off-by: Daniel Borkmann Link: https://lore.kernel.org/bpf/20220831090655.156434-1-ykaliuta@redhat.com Link: https://lore.kernel.org/bpf/20220905090149.61221-1-ykaliuta@redhat.com

kernel/utsname_sysctl.c: print kernel arch

2022-09-12T04:55:12Z

Print the machine hardware name (UTS_MACHINE) in /proc/sys/kernel/arch. This helps people who debug kernel with initramfs with minimal environment (i.e. without coreutils or even busybox) or allow to open sysfs file instead of run 'uname -m' in high level languages. Link: https://lkml.kernel.org/r/20220901194403.3819-1-pvorel@suse.cz Signed-off-by: Petr Vorel Acked-by: Greg Kroah-Hartman Cc: David Sterba Cc: "Eric W . Biederman" Cc: Rafael J. Wysocki Signed-off-by: Andrew Morton

memory tiering: rate limit NUMA migration throughput

2022-09-12T03:25:54Z

In NUMA balancing memory tiering mode, if there are hot pages in slow memory node and cold pages in fast memory node, we need to promote/demote hot/cold pages between the fast and cold memory nodes. A choice is to promote/demote as fast as possible. But the CPU cycles and memory bandwidth consumed by the high promoting/demoting throughput will hurt the latency of some workload because of accessing inflating and slow memory bandwidth contention. A way to resolve this issue is to restrict the max promoting/demoting throughput. It will take longer to finish the promoting/demoting. But the workload latency will be better. This is implemented in this patch as the page promotion rate limit mechanism. The number of the candidate pages to be promoted to the fast memory node via NUMA balancing is counted, if the count exceeds the limit specified by the users, the NUMA balancing promotion will be stopped until the next second. A new sysctl knob kernel.numa_balancing_promote_rate_limit_MBps is added for the users to specify the limit. Link: https://lkml.kernel.org/r/20220713083954.34196-3-ying.huang@intel.com Signed-off-by: "Huang, Ying" Reviewed-by: Baolin Wang Tested-by: Baolin Wang Cc: Dave Hansen Cc: Johannes Weiner Cc: Mel Gorman Cc: Michal Hocko Cc: osalvador Cc: Peter Zijlstra Cc: Rik van Riel Cc: Shakeel Butt Cc: Wei Xu Cc: Yang Shi Cc: Zhong Jiang Cc: Zi Yan Signed-off-by: Andrew Morton

userfaultfd: update documentation to describe /dev/userfaultfd

2022-09-12T03:25:49Z

Explain the different ways to create a new userfaultfd, and how access control works for each way. [axelrasmussen@google.com: improve wording in documentation, per Mike] Link: https://lkml.kernel.org/r/20220819205201.658693-5-axelrasmussen@google.com Link: https://lkml.kernel.org/r/20220808175614.3885028-5-axelrasmussen@google.com Signed-off-by: Axel Rasmussen Acked-by: Peter Xu Reviewed-by: Shuah Khan Cc: Al Viro Cc: Dave Hansen Cc: Dmitry V. Levin Cc: Gleb Fotengauer-Malinovskiy Cc: Hugh Dickins Cc: Jan Kara Cc: Jonathan Corbet Cc: Mel Gorman Cc: Mike Kravetz Cc: Mike Rapoport Cc: Nadav Amit Cc: Suren Baghdasaryan Cc: Vlastimil Babka Cc: Zhang Yi Cc: Mike Rapoport Signed-off-by: Andrew Morton

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2022-08-25T23:07:42Z

drivers/net/ethernet/mellanox/mlx5/core/en_fs.c 21234e3a84c7 ("net/mlx5e: Fix use after free in mlx5e_fs_init()") c7eafc5ed068 ("net/mlx5e: Convert ethtool_steering member of flow_steering struct to pointer") https://lore.kernel.org/all/20220825104410.67d4709c@canb.auug.org.au/ https://lore.kernel.org/all/20220823055533.334471-1-saeed@kernel.org/ Signed-off-by: Jakub Kicinski

Documentation: sysctl: align cells in second content column

2022-08-25T01:42:51Z

Stephen Rothwell reported htmldocs warning when merging net-next tree: Documentation/admin-guide/sysctl/net.rst:37: WARNING: Malformed table. Text in column margin in table line 4. ========= =================== = ========== ================== Directory Content Directory Content ========= =================== = ========== ================== 802 E802 protocol mptcp Multipath TCP appletalk Appletalk protocol netfilter Network Filter ax25 AX25 netrom NET/ROM bridge Bridging rose X.25 PLP layer core General parameter tipc TIPC ethernet Ethernet protocol unix Unix domain sockets ipv4 IP version 4 x25 X.25 protocol ipv6 IP version 6 ========= =================== = ========== ================== The warning above is caused by cells in second "Content" column of /proc/sys/net subdirectory table which are in column margin. Align these cells against the column header to fix the warning. Link: https://lore.kernel.org/linux-next/20220823134905.57ed08d5@canb.auug.org.au/ Fixes: 1202cdd665315c ("Remove DECnet support from kernel") Reported-by: Stephen Rothwell Signed-off-by: Bagas Sanjaya Link: https://lore.kernel.org/r/20220824035804.204322-1-bagasdotme@gmail.com Signed-off-by: Jakub Kicinski

net: Fix data-races around netdev_max_backlog.

2022-08-24T12:46:57Z

While reading netdev_max_backlog, it can be changed concurrently. Thus, we need to add READ_ONCE() to its readers. While at it, we remove the unnecessary spaces in the doc. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Kuniyuki Iwashima Signed-off-by: David S. Miller

Remove DECnet support from kernel

2022-08-22T13:26:30Z

DECnet is an obsolete network protocol that receives more attention from kernel janitors than users. It belongs in computer protocol history museum not in Linux kernel. It has been "Orphaned" in kernel since 2010. The iproute2 support for DECnet was dropped in 5.0 release. The documentation link on Sourceforge says it is abandoned there as well. Leave the UAPI alone to keep userspace programs compiling. This means that there is still an empty neighbour table for AF_DECNET. The table of /proc/sys/net entries was updated to match current directories and reformatted to be alphabetical. Signed-off-by: Stephen Hemminger Acked-by: David Ahern Acked-by: Nikolay Aleksandrov Signed-off-by: David S. Miller