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2021-09-03Merge branch 'akpm' (patches from Andrew)Linus Torvalds1-1/+1
Merge misc updates from Andrew Morton: "173 patches. Subsystems affected by this series: ia64, ocfs2, block, and mm (debug, pagecache, gup, swap, shmem, memcg, selftests, pagemap, mremap, bootmem, sparsemem, vmalloc, kasan, pagealloc, memory-failure, hugetlb, userfaultfd, vmscan, compaction, mempolicy, memblock, oom-kill, migration, ksm, percpu, vmstat, and madvise)" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (173 commits) mm/madvise: add MADV_WILLNEED to process_madvise() mm/vmstat: remove unneeded return value mm/vmstat: simplify the array size calculation mm/vmstat: correct some wrong comments mm/percpu,c: remove obsolete comments of pcpu_chunk_populated() selftests: vm: add COW time test for KSM pages selftests: vm: add KSM merging time test mm: KSM: fix data type selftests: vm: add KSM merging across nodes test selftests: vm: add KSM zero page merging test selftests: vm: add KSM unmerge test selftests: vm: add KSM merge test mm/migrate: correct kernel-doc notation mm: wire up syscall process_mrelease mm: introduce process_mrelease system call memblock: make memblock_find_in_range method private mm/mempolicy.c: use in_task() in mempolicy_slab_node() mm/mempolicy: unify the create() func for bind/interleave/prefer-many policies mm/mempolicy: advertise new MPOL_PREFERRED_MANY mm/hugetlb: add support for mempolicy MPOL_PREFERRED_MANY ...
2021-09-03mm: compaction: support triggering of proactive compaction by userCharan Teja Reddy1-1/+1
The proactive compaction[1] gets triggered for every 500msec and run compaction on the node for COMPACTION_HPAGE_ORDER (usually order-9) pages based on the value set to sysctl.compaction_proactiveness. Triggering the compaction for every 500msec in search of COMPACTION_HPAGE_ORDER pages is not needed for all applications, especially on the embedded system usecases which may have few MB's of RAM. Enabling the proactive compaction in its state will endup in running almost always on such systems. Other side, proactive compaction can still be very much useful for getting a set of higher order pages in some controllable manner(controlled by using the sysctl.compaction_proactiveness). So, on systems where enabling the proactive compaction always may proove not required, can trigger the same from user space on write to its sysctl interface. As an example, say app launcher decide to launch the memory heavy application which can be launched fast if it gets more higher order pages thus launcher can prepare the system in advance by triggering the proactive compaction from userspace. This triggering of proactive compaction is done on a write to sysctl.compaction_proactiveness by user. [1]https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit?id=facdaa917c4d5a376d09d25865f5a863f906234a [akpm@linux-foundation.org: tweak vm.rst, per Mike] Link: https://lkml.kernel.org/r/1627653207-12317-1-git-send-email-charante@codeaurora.org Signed-off-by: Charan Teja Reddy <charante@codeaurora.org> Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Rafael Aquini <aquini@redhat.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Luis Chamberlain <mcgrof@kernel.org> Cc: Kees Cook <keescook@chromium.org> Cc: Iurii Zaikin <yzaikin@google.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Nitin Gupta <nigupta@nvidia.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Khalid Aziz <khalid.aziz@oracle.com> Cc: David Rientjes <rientjes@google.com> Cc: Vinayak Menon <vinmenon@codeaurora.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-08-17sysctl: introduce new proc handler proc_doboolJia He1-0/+42
This is to let bool variable could be correctly displayed in big/little endian sysctl procfs. sizeof(bool) is arch dependent, proc_dobool should work in all arches. Suggested-by: Pan Xinhui <xinhui@linux.vnet.ibm.com> Signed-off-by: Jia He <hejianet@gmail.com> [thuth: rebased the patch to the current kernel version] Signed-off-by: Thomas Huth <thuth@redhat.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-07-02Merge branch 'akpm' (patches from Andrew)Linus Torvalds1-2/+2
Merge more updates from Andrew Morton: "190 patches. Subsystems affected by this patch series: mm (hugetlb, userfaultfd, vmscan, kconfig, proc, z3fold, zbud, ras, mempolicy, memblock, migration, thp, nommu, kconfig, madvise, memory-hotplug, zswap, zsmalloc, zram, cleanups, kfence, and hmm), procfs, sysctl, misc, core-kernel, lib, lz4, checkpatch, init, kprobes, nilfs2, hfs, signals, exec, kcov, selftests, compress/decompress, and ipc" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (190 commits) ipc/util.c: use binary search for max_idx ipc/sem.c: use READ_ONCE()/WRITE_ONCE() for use_global_lock ipc: use kmalloc for msg_queue and shmid_kernel ipc sem: use kvmalloc for sem_undo allocation lib/decompressors: remove set but not used variabled 'level' selftests/vm/pkeys: exercise x86 XSAVE init state selftests/vm/pkeys: refill shadow register after implicit kernel write selftests/vm/pkeys: handle negative sys_pkey_alloc() return code selftests/vm/pkeys: fix alloc_random_pkey() to make it really, really random kcov: add __no_sanitize_coverage to fix noinstr for all architectures exec: remove checks in __register_bimfmt() x86: signal: don't do sas_ss_reset() until we are certain that sigframe won't be abandoned hfsplus: report create_date to kstat.btime hfsplus: remove unnecessary oom message nilfs2: remove redundant continue statement in a while-loop kprobes: remove duplicated strong free_insn_page in x86 and s390 init: print out unknown kernel parameters checkpatch: do not complain about positive return values starting with EPOLL checkpatch: improve the indented label test checkpatch: scripts/spdxcheck.py now requires python3 ...
2021-07-01kernel.h: split out panic and oops helpersAndy Shevchenko1-0/+1
kernel.h is being used as a dump for all kinds of stuff for a long time. Here is the attempt to start cleaning it up by splitting out panic and oops helpers. There are several purposes of doing this: - dropping dependency in bug.h - dropping a loop by moving out panic_notifier.h - unload kernel.h from something which has its own domain At the same time convert users tree-wide to use new headers, although for the time being include new header back to kernel.h to avoid twisted indirected includes for existing users. [akpm@linux-foundation.org: thread_info.h needs limits.h] [andriy.shevchenko@linux.intel.com: ia64 fix] Link: https://lkml.kernel.org/r/20210520130557.55277-1-andriy.shevchenko@linux.intel.com Link: https://lkml.kernel.org/r/20210511074137.33666-1-andriy.shevchenko@linux.intel.com Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org> Co-developed-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Mike Rapoport <rppt@linux.ibm.com> Acked-by: Corey Minyard <cminyard@mvista.com> Acked-by: Christian Brauner <christian.brauner@ubuntu.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Kees Cook <keescook@chromium.org> Acked-by: Wei Liu <wei.liu@kernel.org> Acked-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Sebastian Reichel <sre@kernel.org> Acked-by: Luis Chamberlain <mcgrof@kernel.org> Acked-by: Stephen Boyd <sboyd@kernel.org> Acked-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Acked-by: Helge Deller <deller@gmx.de> # parisc Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-01sysctl: remove redundant assignment to firstJiapeng Chong1-2/+1
Variable first is set to '0', but this value is never read as it is not used later on, hence it is a redundant assignment and can be removed. Clean up the following clang-analyzer warning: kernel/sysctl.c:1562:4: warning: Value stored to 'first' is never read [clang-analyzer-deadcode.DeadStores]. Link: https://lkml.kernel.org/r/1620469990-22182-1-git-send-email-jiapeng.chong@linux.alibaba.com Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com> Reported-by: Abaci Robot <abaci@linux.alibaba.com> Acked-by: Luis Chamberlain <mcgrof@kernel.org> Cc: Kees Cook <keescook@chromium.org> Cc: Iurii Zaikin <yzaikin@google.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Andrii Nakryiko <andrii@kernel.org> Cc: Martin KaFai Lau <kafai@fb.com> Cc: Song Liu <songliubraving@fb.com> Cc: Yonghong Song <yhs@fb.com> Cc: John Fastabend <john.fastabend@gmail.com> Cc: KP Singh <kpsingh@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-30Merge tag 'for-5.14/block-2021-06-29' of git://git.kernel.dk/linux-blockLinus Torvalds1-8/+0
Pull core block updates from Jens Axboe: - disk events cleanup (Christoph) - gendisk and request queue allocation simplifications (Christoph) - bdev_disk_changed cleanups (Christoph) - IO priority improvements (Bart) - Chained bio completion trace fix (Edward) - blk-wbt fixes (Jan) - blk-wbt enable/disable fix (Zhang) - Scheduler dispatch improvements (Jan, Ming) - Shared tagset scheduler improvements (John) - BFQ updates (Paolo, Luca, Pietro) - BFQ lock inversion fix (Jan) - Documentation improvements (Kir) - CLONE_IO block cgroup fix (Tejun) - Remove of ancient and deprecated block dump feature (zhangyi) - Discard merge fix (Ming) - Misc fixes or followup fixes (Colin, Damien, Dan, Long, Max, Thomas, Yang) * tag 'for-5.14/block-2021-06-29' of git://git.kernel.dk/linux-block: (129 commits) block: fix discard request merge block/mq-deadline: Remove a WARN_ON_ONCE() call blk-mq: update hctx->dispatch_busy in case of real scheduler blk: Fix lock inversion between ioc lock and bfqd lock bfq: Remove merged request already in bfq_requests_merged() block: pass a gendisk to bdev_disk_changed block: move bdev_disk_changed block: add the events* attributes to disk_attrs block: move the disk events code to a separate file block: fix trace completion for chained bio block/partitions/msdos: Fix typo inidicator -> indicator block, bfq: reset waker pointer with shared queues block, bfq: check waker only for queues with no in-flight I/O block, bfq: avoid delayed merge of async queues block, bfq: boost throughput by extending queue-merging times block, bfq: consider also creation time in delayed stable merge block, bfq: fix delayed stable merge check block, bfq: let also stably merged queues enjoy weight raising blk-wbt: make sure throttle is enabled properly blk-wbt: introduce a new disable state to prevent false positive by rwb_enabled() ...
2021-06-29Merge branch 'akpm' (patches from Andrew)Linus Torvalds1-4/+4
Merge misc updates from Andrew Morton: "191 patches. Subsystems affected by this patch series: kthread, ia64, scripts, ntfs, squashfs, ocfs2, kernel/watchdog, and mm (gup, pagealloc, slab, slub, kmemleak, dax, debug, pagecache, gup, swap, memcg, pagemap, mprotect, bootmem, dma, tracing, vmalloc, kasan, initialization, pagealloc, and memory-failure)" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (191 commits) mm,hwpoison: make get_hwpoison_page() call get_any_page() mm,hwpoison: send SIGBUS with error virutal address mm/page_alloc: split pcp->high across all online CPUs for cpuless nodes mm/page_alloc: allow high-order pages to be stored on the per-cpu lists mm: replace CONFIG_FLAT_NODE_MEM_MAP with CONFIG_FLATMEM mm: replace CONFIG_NEED_MULTIPLE_NODES with CONFIG_NUMA docs: remove description of DISCONTIGMEM arch, mm: remove stale mentions of DISCONIGMEM mm: remove CONFIG_DISCONTIGMEM m68k: remove support for DISCONTIGMEM arc: remove support for DISCONTIGMEM arc: update comment about HIGHMEM implementation alpha: remove DISCONTIGMEM and NUMA mm/page_alloc: move free_the_page mm/page_alloc: fix counting of managed_pages mm/page_alloc: improve memmap_pages dbg msg mm: drop SECTION_SHIFT in code comments mm/page_alloc: introduce vm.percpu_pagelist_high_fraction mm/page_alloc: limit the number of pages on PCP lists when reclaim is active mm/page_alloc: scale the number of pages that are batch freed ...
2021-06-29mm/page_alloc: introduce vm.percpu_pagelist_high_fractionMel Gorman1-0/+8
This introduces a new sysctl vm.percpu_pagelist_high_fraction. It is similar to the old vm.percpu_pagelist_fraction. The old sysctl increased both pcp->batch and pcp->high with the higher pcp->high potentially reducing zone->lock contention. However, the higher pcp->batch value also potentially increased allocation latency while the PCP was refilled. This sysctl only adjusts pcp->high so that zone->lock contention is potentially reduced but allocation latency during a PCP refill remains the same. # grep -E "high:|batch" /proc/zoneinfo | tail -2 high: 649 batch: 63 # sysctl vm.percpu_pagelist_high_fraction=8 # grep -E "high:|batch" /proc/zoneinfo | tail -2 high: 35071 batch: 63 # sysctl vm.percpu_pagelist_high_fraction=64 high: 4383 batch: 63 # sysctl vm.percpu_pagelist_high_fraction=0 high: 649 batch: 63 [mgorman@techsingularity.net: fix documentation] Link: https://lkml.kernel.org/r/20210528151010.GQ30378@techsingularity.net Link: https://lkml.kernel.org/r/20210525080119.5455-7-mgorman@techsingularity.net Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: Dave Hansen <dave.hansen@linux.intel.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Hillf Danton <hdanton@sina.com> Cc: Michal Hocko <mhocko@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-29mm/page_alloc: delete vm.percpu_pagelist_fractionMel Gorman1-8/+0
Patch series "Calculate pcp->high based on zone sizes and active CPUs", v2. The per-cpu page allocator (PCP) is meant to reduce contention on the zone lock but the sizing of batch and high is archaic and neither takes the zone size into account or the number of CPUs local to a zone. With larger zones and more CPUs per node, the contention is getting worse. Furthermore, the fact that vm.percpu_pagelist_fraction adjusts both batch and high values means that the sysctl can reduce zone lock contention but also increase allocation latencies. This series disassociates pcp->high from pcp->batch and then scales pcp->high based on the size of the local zone with limited impact to reclaim and accounting for active CPUs but leaves pcp->batch static. It also adapts the number of pages that can be on the pcp list based on recent freeing patterns. The motivation is partially to adjust to larger memory sizes but is also driven by the fact that large batches of page freeing via release_pages() often shows zone contention as a major part of the problem. Another is a bug report based on an older kernel where a multi-terabyte process can takes several minutes to exit. A workaround was to use vm.percpu_pagelist_fraction to increase the pcp->high value but testing indicated that a production workload could not use the same values because of an increase in allocation latencies. Unfortunately, I cannot reproduce this test case myself as the multi-terabyte machines are in active use but it should alleviate the problem. The series aims to address both and partially acts as a pre-requisite. pcp only works with order-0 which is useless for SLUB (when using high orders) and THP (unconditionally). To store high-order pages on PCP, the pcp->high values need to be increased first. This patch (of 6): The vm.percpu_pagelist_fraction is used to increase the batch and high limits for the per-cpu page allocator (PCP). The intent behind the sysctl is to reduce zone lock acquisition when allocating/freeing pages but it has a problem. While it can decrease contention, it can also increase latency on the allocation side due to unreasonably large batch sizes. This leads to games where an administrator adjusts percpu_pagelist_fraction on the fly to work around contention and allocation latency problems. This series aims to alleviate the problems with zone lock contention while avoiding the allocation-side latency problems. For the purposes of review, it's easier to remove this sysctl now and reintroduce a similar sysctl later in the series that deals only with pcp->high. Link: https://lkml.kernel.org/r/20210525080119.5455-1-mgorman@techsingularity.net Link: https://lkml.kernel.org/r/20210525080119.5455-2-mgorman@techsingularity.net Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: Dave Hansen <dave.hansen@linux.intel.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Hillf Danton <hdanton@sina.com> Cc: Michal Hocko <mhocko@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-03Merge branch 'sched/urgent' into sched/core, to pick up fixesIngo Molnar1-5/+24
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2021-05-24block_dump: remove block_dump featurezhangyi (F)1-8/+0
We have already delete block_dump feature in mark_inode_dirty() because it can be replaced by tracepoints, now we also remove the part in submit_bio() for the same reason. The part of block dump feature in submit_bio() dump the write process, write region and sectors on the target disk into kernel message. it can be replaced by block_bio_queue tracepoint in submit_bio_checks(), so we do not need block_dump anymore, remove the whole block_dump feature. Signed-off-by: zhangyi (F) <yi.zhang@huawei.com> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20210313030146.2882027-3-yi.zhang@huawei.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-05-12delayacct: Add sysctl to enable at runtimePeter Zijlstra1-0/+12
Just like sched_schedstats, allow runtime enabling (and disabling) of delayacct. This is useful if one forgot to add the delayacct boot time option. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/YJkhebGJAywaZowX@hirez.programming.kicks-ass.net
2021-05-11Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpfDavid S. Miller1-5/+24
Daniel Borkmann says: ==================== pull-request: bpf 2021-05-11 The following pull-request contains BPF updates for your *net* tree. We've added 13 non-merge commits during the last 8 day(s) which contain a total of 21 files changed, 817 insertions(+), 382 deletions(-). The main changes are: 1) Fix multiple ringbuf bugs in particular to prevent writable mmap of read-only pages, from Andrii Nakryiko & Thadeu Lima de Souza Cascardo. 2) Fix verifier alu32 known-const subregister bound tracking for bitwise operations and/or/xor, from Daniel Borkmann. 3) Reject trampoline attachment for functions with variable arguments, and also add a deny list of other forbidden functions, from Jiri Olsa. 4) Fix nested bpf_bprintf_prepare() calls used by various helpers by switching to per-CPU buffers, from Florent Revest. 5) Fix kernel compilation with BTF debug info on ppc64 due to pahole missing TCP-CC functions like cubictcp_init, from Martin KaFai Lau. 6) Add a kconfig entry to provide an option to disallow unprivileged BPF by default, from Daniel Borkmann. 7) Fix libbpf compilation for older libelf when GELF_ST_VISIBILITY() macro is not available, from Arnaldo Carvalho de Melo. 8) Migrate test_tc_redirect to test_progs framework as prep work for upcoming skb_change_head() fix & selftest, from Jussi Maki. 9) Fix a libbpf segfault in add_dummy_ksym_var() if BTF is not present, from Ian Rogers. 10) Fix tx_only micro-benchmark in xdpsock BPF sample with proper frame size, from Magnus Karlsson. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2021-05-11bpf: Add kconfig knob for disabling unpriv bpf by defaultDaniel Borkmann1-5/+24
Add a kconfig knob which allows for unprivileged bpf to be disabled by default. If set, the knob sets /proc/sys/kernel/unprivileged_bpf_disabled to value of 2. This still allows a transition of 2 -> {0,1} through an admin. Similarly, this also still keeps 1 -> {1} behavior intact, so that once set to permanently disabled, it cannot be undone aside from a reboot. We've also added extra2 with max of 2 for the procfs handler, so that an admin still has a chance to toggle between 0 <-> 2. Either way, as an additional alternative, applications can make use of CAP_BPF that we added a while ago. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/74ec548079189e4e4dffaeb42b8987bb3c852eee.1620765074.git.daniel@iogearbox.net
2021-05-05mm/compaction: remove unused variable sysctl_compact_memoryPintu Kumar1-1/+1
The sysctl_compact_memory is mostly unused in mm/compaction.c It just acts as a place holder for sysctl to store .data. But the .data itself is not needed here. So we can get ride of this variable completely and make .data as NULL. This will also eliminate the extern declaration from header file. No functionality is broken or changed this way. Link: https://lkml.kernel.org/r/1614852224-14671-1-git-send-email-pintu@codeaurora.org Signed-off-by: Pintu Kumar <pintu@codeaurora.org> Signed-off-by: Pintu Agarwal <pintu.ping@gmail.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-04-29Merge tag 'net-next-5.13' of ↵Linus Torvalds1-0/+65
git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next Pull networking updates from Jakub Kicinski: "Core: - bpf: - allow bpf programs calling kernel functions (initially to reuse TCP congestion control implementations) - enable task local storage for tracing programs - remove the need to store per-task state in hash maps, and allow tracing programs access to task local storage previously added for BPF_LSM - add bpf_for_each_map_elem() helper, allowing programs to walk all map elements in a more robust and easier to verify fashion - sockmap: support UDP and cross-protocol BPF_SK_SKB_VERDICT redirection - lpm: add support for batched ops in LPM trie - add BTF_KIND_FLOAT support - mostly to allow use of BTF on s390 which has floats in its headers files - improve BPF syscall documentation and extend the use of kdoc parsing scripts we already employ for bpf-helpers - libbpf, bpftool: support static linking of BPF ELF files - improve support for encapsulation of L2 packets - xdp: restructure redirect actions to avoid a runtime lookup, improving performance by 4-8% in microbenchmarks - xsk: build skb by page (aka generic zerocopy xmit) - improve performance of software AF_XDP path by 33% for devices which don't need headers in the linear skb part (e.g. virtio) - nexthop: resilient next-hop groups - improve path stability on next-hops group changes (incl. offload for mlxsw) - ipv6: segment routing: add support for IPv4 decapsulation - icmp: add support for RFC 8335 extended PROBE messages - inet: use bigger hash table for IP ID generation - tcp: deal better with delayed TX completions - make sure we don't give up on fast TCP retransmissions only because driver is slow in reporting that it completed transmitting the original - tcp: reorder tcp_congestion_ops for better cache locality - mptcp: - add sockopt support for common TCP options - add support for common TCP msg flags - include multiple address ids in RM_ADDR - add reset option support for resetting one subflow - udp: GRO L4 improvements - improve 'forward' / 'frag_list' co-existence with UDP tunnel GRO, allowing the first to take place correctly even for encapsulated UDP traffic - micro-optimize dev_gro_receive() and flow dissection, avoid retpoline overhead on VLAN and TEB GRO - use less memory for sysctls, add a new sysctl type, to allow using u8 instead of "int" and "long" and shrink networking sysctls - veth: allow GRO without XDP - this allows aggregating UDP packets before handing them off to routing, bridge, OvS, etc. - allow specifing ifindex when device is moved to another namespace - netfilter: - nft_socket: add support for cgroupsv2 - nftables: add catch-all set element - special element used to define a default action in case normal lookup missed - use net_generic infra in many modules to avoid allocating per-ns memory unnecessarily - xps: improve the xps handling to avoid potential out-of-bound accesses and use-after-free when XPS change race with other re-configuration under traffic - add a config knob to turn off per-cpu netdev refcnt to catch underflows in testing Device APIs: - add WWAN subsystem to organize the WWAN interfaces better and hopefully start driving towards more unified and vendor- independent APIs - ethtool: - add interface for reading IEEE MIB stats (incl. mlx5 and bnxt support) - allow network drivers to dump arbitrary SFP EEPROM data, current offset+length API was a poor fit for modern SFP which define EEPROM in terms of pages (incl. mlx5 support) - act_police, flow_offload: add support for packet-per-second policing (incl. offload for nfp) - psample: add additional metadata attributes like transit delay for packets sampled from switch HW (and corresponding egress and policy-based sampling in the mlxsw driver) - dsa: improve support for sandwiched LAGs with bridge and DSA - netfilter: - flowtable: use direct xmit in topologies with IP forwarding, bridging, vlans etc. - nftables: counter hardware offload support - Bluetooth: - improvements for firmware download w/ Intel devices - add support for reading AOSP vendor capabilities - add support for virtio transport driver - mac80211: - allow concurrent monitor iface and ethernet rx decap - set priority and queue mapping for injected frames - phy: add support for Clause-45 PHY Loopback - pci/iov: add sysfs MSI-X vector assignment interface to distribute MSI-X resources to VFs (incl. mlx5 support) New hardware/drivers: - dsa: mv88e6xxx: add support for Marvell mv88e6393x - 11-port Ethernet switch with 8x 1-Gigabit Ethernet and 3x 10-Gigabit interfaces. - dsa: support for legacy Broadcom tags used on BCM5325, BCM5365 and BCM63xx switches - Microchip KSZ8863 and KSZ8873; 3x 10/100Mbps Ethernet switches - ath11k: support for QCN9074 a 802.11ax device - Bluetooth: Broadcom BCM4330 and BMC4334 - phy: Marvell 88X2222 transceiver support - mdio: add BCM6368 MDIO mux bus controller - r8152: support RTL8153 and RTL8156 (USB Ethernet) chips - mana: driver for Microsoft Azure Network Adapter (MANA) - Actions Semi Owl Ethernet MAC - can: driver for ETAS ES58X CAN/USB interfaces Pure driver changes: - add XDP support to: enetc, igc, stmmac - add AF_XDP support to: stmmac - virtio: - page_to_skb() use build_skb when there's sufficient tailroom (21% improvement for 1000B UDP frames) - support XDP even without dedicated Tx queues - share the Tx queues with the stack when necessary - mlx5: - flow rules: add support for mirroring with conntrack, matching on ICMP, GTP, flex filters and more - support packet sampling with flow offloads - persist uplink representor netdev across eswitch mode changes - allow coexistence of CQE compression and HW time-stamping - add ethtool extended link error state reporting - ice, iavf: support flow filters, UDP Segmentation Offload - dpaa2-switch: - move the driver out of staging - add spanning tree (STP) support - add rx copybreak support - add tc flower hardware offload on ingress traffic - ionic: - implement Rx page reuse - support HW PTP time-stamping - octeon: support TC hardware offloads - flower matching on ingress and egress ratelimitting. - stmmac: - add RX frame steering based on VLAN priority in tc flower - support frame preemption (FPE) - intel: add cross time-stamping freq difference adjustment - ocelot: - support forwarding of MRP frames in HW - support multiple bridges - support PTP Sync one-step timestamping - dsa: mv88e6xxx, dpaa2-switch: offload bridge port flags like learning, flooding etc. - ipa: add IPA v4.5, v4.9 and v4.11 support (Qualcomm SDX55, SM8350, SC7280 SoCs) - mt7601u: enable TDLS support - mt76: - add support for 802.3 rx frames (mt7915/mt7615) - mt7915 flash pre-calibration support - mt7921/mt7663 runtime power management fixes" * tag 'net-next-5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (2451 commits) net: selftest: fix build issue if INET is disabled net: netrom: nr_in: Remove redundant assignment to ns net: tun: Remove redundant assignment to ret net: phy: marvell: add downshift support for M88E1240 net: dsa: ksz: Make reg_mib_cnt a u8 as it never exceeds 255 net/sched: act_ct: Remove redundant ct get and check icmp: standardize naming of RFC 8335 PROBE constants bpf, selftests: Update array map tests for per-cpu batched ops bpf: Add batched ops support for percpu array bpf: Implement formatted output helpers with bstr_printf seq_file: Add a seq_bprintf function sfc: adjust efx->xdp_tx_queue_count with the real number of initialized queues net:nfc:digital: Fix a double free in digital_tg_recv_dep_req net: fix a concurrency bug in l2tp_tunnel_register() net/smc: Remove redundant assignment to rc mpls: Remove redundant assignment to err llc2: Remove redundant assignment to rc net/tls: Remove redundant initialization of record rds: Remove redundant assignment to nr_sig dt-bindings: net: mdio-gpio: add compatible for microchip,mdio-smi0 ...
2021-04-29Merge tag 'fsnotify_for_v5.13-rc1' of ↵Linus Torvalds1-1/+11
git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs Pull fsnotify updates from Jan Kara: - support for limited fanotify functionality for unpriviledged users - faster merging of fanotify events - a few smaller fsnotify improvements * tag 'fsnotify_for_v5.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs: shmem: allow reporting fanotify events with file handles on tmpfs fs: introduce a wrapper uuid_to_fsid() fanotify_user: use upper_32_bits() to verify mask fanotify: support limited functionality for unprivileged users fanotify: configurable limits via sysfs fanotify: limit number of event merge attempts fsnotify: use hash table for faster events merge fanotify: mix event info and pid into merge key hash fanotify: reduce event objectid to 29-bit hash fsnotify: allow fsnotify_{peek,remove}_first_event with empty queue
2021-04-16sched: Move SCHED_DEBUG sysctl to debugfsPeter Zijlstra1-96/+0
Stop polluting sysctl with undocumented knobs that really are debug only, move them all to /debug/sched/ along with the existing /debug/sched_* files that already exist. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Tested-by: Valentin Schneider <valentin.schneider@arm.com> Link: https://lkml.kernel.org/r/20210412102001.287610138@infradead.org
2021-04-16sched: Remove sched_schedstats sysctl out from under SCHED_DEBUGPeter Zijlstra1-11/+11
CONFIG_SCHEDSTATS does not depend on SCHED_DEBUG, it is inconsistent to have the sysctl depend on it. Suggested-by: Mel Gorman <mgorman@suse.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Valentin Schneider <valentin.schneider@arm.com> Link: https://lkml.kernel.org/r/20210412102001.161151631@infradead.org
2021-04-16sched/numa: Allow runtime enabling/disabling of NUMA balance without SCHED_DEBUGMel Gorman1-1/+3
The ability to enable/disable NUMA balancing is not a debugging feature and should not depend on CONFIG_SCHED_DEBUG. For example, machines within a HPC cluster may disable NUMA balancing temporarily for some jobs and re-enable it for other jobs without needing to reboot. This patch removes the dependency on CONFIG_SCHED_DEBUG for kernel.numa_balancing sysctl. The other numa balancing related sysctls are left as-is because if they need to be tuned then it is more likely that NUMA balancing needs to be fixed instead. Signed-off-by: Mel Gorman <mgorman@suse.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Valentin Schneider <valentin.schneider@arm.com> Link: https://lkml.kernel.org/r/20210324133916.GQ15768@suse.de
2021-03-25sysctl: add proc_dou8vec_minmax()Eric Dumazet1-0/+65
Networking has many sysctls that could fit in one u8. This patch adds proc_dou8vec_minmax() for this purpose. Note that the .extra1 and .extra2 fields are pointing to integers, because it makes conversions easier. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-03-16fanotify: configurable limits via sysfsAmir Goldstein1-1/+11
fanotify has some hardcoded limits. The only APIs to escape those limits are FAN_UNLIMITED_QUEUE and FAN_UNLIMITED_MARKS. Allow finer grained tuning of the system limits via sysfs tunables under /proc/sys/fs/fanotify, similar to tunables under /proc/sys/fs/inotify, with some minor differences. - max_queued_events - global system tunable for group queue size limit. Like the inotify tunable with the same name, it defaults to 16384 and applies on initialization of a new group. - max_user_marks - user ns tunable for marks limit per user. Like the inotify tunable named max_user_watches, on a machine with sufficient RAM and it defaults to 1048576 in init userns and can be further limited per containing user ns. - max_user_groups - user ns tunable for number of groups per user. Like the inotify tunable named max_user_instances, it defaults to 128 in init userns and can be further limited per containing user ns. The slightly different tunable names used for fanotify are derived from the "group" and "mark" terminology used in the fanotify man pages and throughout the code. Considering the fact that the default value for max_user_instances was increased in kernel v5.10 from 8192 to 1048576, leaving the legacy fanotify limit of 8192 marks per group in addition to the max_user_marks limit makes little sense, so the per group marks limit has been removed. Note that when a group is initialized with FAN_UNLIMITED_MARKS, its own marks are not accounted in the per user marks account, so in effect the limit of max_user_marks is only for the collection of groups that are not initialized with FAN_UNLIMITED_MARKS. Link: https://lore.kernel.org/r/20210304112921.3996419-2-amir73il@gmail.com Suggested-by: Jan Kara <jack@suse.cz> Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2021-02-26sysctl.c: fix underflow value setting risk in vm_tableLin Feng1-4/+4
Apart from subsystem specific .proc_handler handler, all ctl_tables with extra1 and extra2 members set should use proc_dointvec_minmax instead of proc_dointvec, or the limit set in extra* never work and potentially echo underflow values(negative numbers) is likely make system unstable. Especially vfs_cache_pressure and zone_reclaim_mode, -1 is apparently not a valid value, but we can set to them. And then kernel may crash. # echo -1 > /proc/sys/vm/vfs_cache_pressure Link: https://lkml.kernel.org/r/20201223105535.2875-1-linf@wangsu.com Signed-off-by: Lin Feng <linf@wangsu.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-11-19rcu: Panic after fixed number of stallschao1-0/+11
Some stalls are transient, so that system fully recovers. This commit therefore allows users to configure the number of stalls that must happen in order to trigger kernel panic. Signed-off-by: chao <chao@eero.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-09-17mm: allow a controlled amount of unfairness in the page lockLinus Torvalds1-0/+8
Commit 2a9127fcf229 ("mm: rewrite wait_on_page_bit_common() logic") made the page locking entirely fair, in that if a waiter came in while the lock was held, the lock would be transferred to the lockers strictly in order. That was intended to finally get rid of the long-reported watchdog failures that involved the page lock under extreme load, where a process could end up waiting essentially forever, as other page lockers stole the lock from under it. It also improved some benchmarks, but it ended up causing huge performance regressions on others, simply because fair lock behavior doesn't end up giving out the lock as aggressively, causing better worst-case latency, but potentially much worse average latencies and throughput. Instead of reverting that change entirely, this introduces a controlled amount of unfairness, with a sysctl knob to tune it if somebody needs to. But the default value should hopefully be good for any normal load, allowing a few rounds of lock stealing, but enforcing the strict ordering before the lock has been stolen too many times. There is also a hint from Matthieu Baerts that the fair page coloring may end up exposing an ABBA deadlock that is hidden by the usual optimistic lock stealing, and while the unfairness doesn't fix the fundamental issue (and I'm still looking at that), it avoids it in practice. The amount of unfairness can be modified by writing a new value to the 'sysctl_page_lock_unfairness' variable (default value of 5, exposed through /proc/sys/vm/page_lock_unfairness), but that is hopefully something we'd use mainly for debugging rather than being necessary for any deep system tuning. This whole issue has exposed just how critical the page lock can be, and how contended it gets under certain locks. And the main contention doesn't really seem to be anything related to IO (which was the origin of this lock), but for things like just verifying that the page file mapping is stable while faulting in the page into a page table. Link: https://lore.kernel.org/linux-fsdevel/ed8442fd-6f54-dd84-cd4a-941e8b7ee603@MichaelLarabel.com/ Link: https://www.phoronix.com/scan.php?page=article&item=linux-50-59&num=1 Link: https://lore.kernel.org/linux-fsdevel/c560a38d-8313-51fb-b1ec-e904bd8836bc@tessares.net/ Reported-and-tested-by: Michael Larabel <Michael@michaellarabel.com> Tested-by: Matthieu Baerts <matthieu.baerts@tessares.net> Cc: Dave Chinner <david@fromorbit.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Chris Mason <clm@fb.com> Cc: Jan Kara <jack@suse.cz> Cc: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-24bpf, sysctl: Let bpf_stats_handler take a kernel pointer bufferTobias Klauser1-2/+1
Commit 32927393dc1c ("sysctl: pass kernel pointers to ->proc_handler") changed ctl_table.proc_handler to take a kernel pointer. Adjust the signature of bpf_stats_handler to match ctl_table.proc_handler which fixes the following sparse warning: kernel/sysctl.c:226:49: warning: incorrect type in argument 3 (different address spaces) kernel/sysctl.c:226:49: expected void * kernel/sysctl.c:226:49: got void [noderef] __user *buffer kernel/sysctl.c:2640:35: warning: incorrect type in initializer (incompatible argument 3 (different address spaces)) kernel/sysctl.c:2640:35: expected int ( [usertype] *proc_handler )( ... ) kernel/sysctl.c:2640:35: got int ( * )( ... ) Fixes: 32927393dc1c ("sysctl: pass kernel pointers to ->proc_handler") Signed-off-by: Tobias Klauser <tklauser@distanz.ch> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Cc: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/bpf/20200824142047.22043-1-tklauser@distanz.ch
2020-08-12mm: use unsigned types for fragmentation scoreNitin Gupta1-1/+1
Proactive compaction uses per-node/zone "fragmentation score" which is always in range [0, 100], so use unsigned type of these scores as well as for related constants. Signed-off-by: Nitin Gupta <nigupta@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Baoquan He <bhe@redhat.com> Cc: Luis Chamberlain <mcgrof@kernel.org> Cc: Kees Cook <keescook@chromium.org> Cc: Iurii Zaikin <yzaikin@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Link: http://lkml.kernel.org/r/20200618010319.13159-1-nigupta@nvidia.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-12mm: proactive compactionNitin Gupta1-0/+9
For some applications, we need to allocate almost all memory as hugepages. However, on a running system, higher-order allocations can fail if the memory is fragmented. Linux kernel currently does on-demand compaction as we request more hugepages, but this style of compaction incurs very high latency. Experiments with one-time full memory compaction (followed by hugepage allocations) show that kernel is able to restore a highly fragmented memory state to a fairly compacted memory state within <1 sec for a 32G system. Such data suggests that a more proactive compaction can help us allocate a large fraction of memory as hugepages keeping allocation latencies low. For a more proactive compaction, the approach taken here is to define a new sysctl called 'vm.compaction_proactiveness' which dictates bounds for external fragmentation which kcompactd tries to maintain. The tunable takes a value in range [0, 100], with a default of 20. Note that a previous version of this patch [1] was found to introduce too many tunables (per-order extfrag{low, high}), but this one reduces them to just one sysctl. Also, the new tunable is an opaque value instead of asking for specific bounds of "external fragmentation", which would have been difficult to estimate. The internal interpretation of this opaque value allows for future fine-tuning. Currently, we use a simple translation from this tunable to [low, high] "fragmentation score" thresholds (low=100-proactiveness, high=low+10%). The score for a node is defined as weighted mean of per-zone external fragmentation. A zone's present_pages determines its weight. To periodically check per-node score, we reuse per-node kcompactd threads, which are woken up every 500 milliseconds to check the same. If a node's score exceeds its high threshold (as derived from user-provided proactiveness value), proactive compaction is started until its score reaches its low threshold value. By default, proactiveness is set to 20, which implies threshold values of low=80 and high=90. This patch is largely based on ideas from Michal Hocko [2]. See also the LWN article [3]. Performance data ================ System: x64_64, 1T RAM, 80 CPU threads. Kernel: 5.6.0-rc3 + this patch echo madvise | sudo tee /sys/kernel/mm/transparent_hugepage/enabled echo madvise | sudo tee /sys/kernel/mm/transparent_hugepage/defrag Before starting the driver, the system was fragmented from a userspace program that allocates all memory and then for each 2M aligned section, frees 3/4 of base pages using munmap. The workload is mainly anonymous userspace pages, which are easy to move around. I intentionally avoided unmovable pages in this test to see how much latency we incur when hugepage allocations hit direct compaction. 1. Kernel hugepage allocation latencies With the system in such a fragmented state, a kernel driver then allocates as many hugepages as possible and measures allocation latency: (all latency values are in microseconds) - With vanilla 5.6.0-rc3 percentile latency –––––––––– ––––––– 5 7894 10 9496 25 12561 30 15295 40 18244 50 21229 60 27556 75 30147 80 31047 90 32859 95 33799 Total 2M hugepages allocated = 383859 (749G worth of hugepages out of 762G total free => 98% of free memory could be allocated as hugepages) - With 5.6.0-rc3 + this patch, with proactiveness=20 sysctl -w vm.compaction_proactiveness=20 percentile latency –––––––––– ––––––– 5 2 10 2 25 3 30 3 40 3 50 4 60 4 75 4 80 4 90 5 95 429 Total 2M hugepages allocated = 384105 (750G worth of hugepages out of 762G total free => 98% of free memory could be allocated as hugepages) 2. JAVA heap allocation In this test, we first fragment memory using the same method as for (1). Then, we start a Java process with a heap size set to 700G and request the heap to be allocated with THP hugepages. We also set THP to madvise to allow hugepage backing of this heap. /usr/bin/time java -Xms700G -Xmx700G -XX:+UseTransparentHugePages -XX:+AlwaysPreTouch The above command allocates 700G of Java heap using hugepages. - With vanilla 5.6.0-rc3 17.39user 1666.48system 27:37.89elapsed - With 5.6.0-rc3 + this patch, with proactiveness=20 8.35user 194.58system 3:19.62elapsed Elapsed time remains around 3:15, as proactiveness is further increased. Note that proactive compaction happens throughout the runtime of these workloads. The situation of one-time compaction, sufficient to supply hugepages for following allocation stream, can probably happen for more extreme proactiveness values, like 80 or 90. In the above Java workload, proactiveness is set to 20. The test starts with a node's score of 80 or higher, depending on the delay between the fragmentation step and starting the benchmark, which gives more-or-less time for the initial round of compaction. As t he benchmark consumes hugepages, node's score quickly rises above the high threshold (90) and proactive compaction starts again, which brings down the score to the low threshold level (80). Repeat. bpftrace also confirms proactive compaction running 20+ times during the runtime of this Java benchmark. kcompactd threads consume 100% of one of the CPUs while it tries to bring a node's score within thresholds. Backoff behavior ================ Above workloads produce a memory state which is easy to compact. However, if memory is filled with unmovable pages, proactive compaction should essentially back off. To test this aspect: - Created a kernel driver that allocates almost all memory as hugepages followed by freeing first 3/4 of each hugepage. - Set proactiveness=40 - Note that proactive_compact_node() is deferred maximum number of times with HPAGE_FRAG_CHECK_INTERVAL_MSEC of wait between each check (=> ~30 seconds between retries). [1] https://patchwork.kernel.org/patch/11098289/ [2] https://lore.kernel.org/linux-mm/20161230131412.GI13301@dhcp22.suse.cz/ [3] https://lwn.net/Articles/817905/ Signed-off-by: Nitin Gupta <nigupta@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Tested-by: Oleksandr Natalenko <oleksandr@redhat.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Khalid Aziz <khalid.aziz@oracle.com> Reviewed-by: Oleksandr Natalenko <oleksandr@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Khalid Aziz <khalid.aziz@oracle.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: David Rientjes <rientjes@google.com> Cc: Nitin Gupta <ngupta@nitingupta.dev> Cc: Oleksandr Natalenko <oleksandr@redhat.com> Link: http://lkml.kernel.org/r/20200616204527.19185-1-nigupta@nvidia.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-07mm: adjust vm_committed_as_batch according to vm overcommit policyFeng Tang1-1/+1
When checking a performance change for will-it-scale scalability mmap test [1], we found very high lock contention for spinlock of percpu counter 'vm_committed_as': 94.14% 0.35% [kernel.kallsyms] [k] _raw_spin_lock_irqsave 48.21% _raw_spin_lock_irqsave;percpu_counter_add_batch;__vm_enough_memory;mmap_region;do_mmap; 45.91% _raw_spin_lock_irqsave;percpu_counter_add_batch;__do_munmap; Actually this heavy lock contention is not always necessary. The 'vm_committed_as' needs to be very precise when the strict OVERCOMMIT_NEVER policy is set, which requires a rather small batch number for the percpu counter. So keep 'batch' number unchanged for strict OVERCOMMIT_NEVER policy, and lift it to 64X for OVERCOMMIT_ALWAYS and OVERCOMMIT_GUESS policies. Also add a sysctl handler to adjust it when the policy is reconfigured. Benchmark with the same testcase in [1] shows 53% improvement on a 8C/16T desktop, and 2097%(20X) on a 4S/72C/144T server. We tested with test platforms in 0day (server, desktop and laptop), and 80%+ platforms shows improvements with that test. And whether it shows improvements depends on if the test mmap size is bigger than the batch number computed. And if the lift is 16X, 1/3 of the platforms will show improvements, though it should help the mmap/unmap usage generally, as Michal Hocko mentioned: : I believe that there are non-synthetic worklaods which would benefit from : a larger batch. E.g. large in memory databases which do large mmaps : during startups from multiple threads. [1] https://lore.kernel.org/lkml/20200305062138.GI5972@shao2-debian/ Signed-off-by: Feng Tang <feng.tang@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Qian Cai <cai@lca.pw> Cc: Kees Cook <keescook@chromium.org> Cc: Andi Kleen <andi.kleen@intel.com> Cc: Tim Chen <tim.c.chen@intel.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Huang Ying <ying.huang@intel.com> Cc: Christoph Lameter <cl@linux.com> Cc: Dennis Zhou <dennis@kernel.org> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: kernel test robot <rong.a.chen@intel.com> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Tejun Heo <tj@kernel.org> Link: http://lkml.kernel.org/r/1589611660-89854-4-git-send-email-feng.tang@intel.com Link: http://lkml.kernel.org/r/1592725000-73486-4-git-send-email-feng.tang@intel.com Link: http://lkml.kernel.org/r/1594389708-60781-5-git-send-email-feng.tang@intel.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-07-29sched/uclamp: Add a new sysctl to control RT default boost valueQais Yousef1-0/+7
RT tasks by default run at the highest capacity/performance level. When uclamp is selected this default behavior is retained by enforcing the requested uclamp.min (p->uclamp_req[UCLAMP_MIN]) of the RT tasks to be uclamp_none(UCLAMP_MAX), which is SCHED_CAPACITY_SCALE; the maximum value. This is also referred to as 'the default boost value of RT tasks'. See commit 1a00d999971c ("sched/uclamp: Set default clamps for RT tasks"). On battery powered devices, it is desired to control this default (currently hardcoded) behavior at runtime to reduce energy consumed by RT tasks. For example, a mobile device manufacturer where big.LITTLE architecture is dominant, the performance of the little cores varies across SoCs, and on high end ones the big cores could be too power hungry. Given the diversity of SoCs, the new knob allows manufactures to tune the best performance/power for RT tasks for the particular hardware they run on. They could opt to further tune the value when the user selects a different power saving mode or when the device is actively charging. The runtime aspect of it further helps in creating a single kernel image that can be run on multiple devices that require different tuning. Keep in mind that a lot of RT tasks in the system are created by the kernel. On Android for instance I can see over 50 RT tasks, only a handful of which created by the Android framework. To control the default behavior globally by system admins and device integrator, introduce the new sysctl_sched_uclamp_util_min_rt_default to change the default boost value of the RT tasks. I anticipate this to be mostly in the form of modifying the init script of a particular device. To avoid polluting the fast path with unnecessary code, the approach taken is to synchronously do the update by traversing all the existing tasks in the system. This could race with a concurrent fork(), which is dealt with by introducing sched_post_fork() function which will ensure the racy fork will get the right update applied. Tested on Juno-r2 in combination with the RT capacity awareness [1]. By default an RT task will go to the highest capacity CPU and run at the maximum frequency, which is particularly energy inefficient on high end mobile devices because the biggest core[s] are 'huge' and power hungry. With this patch the RT task can be controlled to run anywhere by default, and doesn't cause the frequency to be maximum all the time. Yet any task that really needs to be boosted can easily escape this default behavior by modifying its requested uclamp.min value (p->uclamp_req[UCLAMP_MIN]) via sched_setattr() syscall. [1] 804d402fb6f6: ("sched/rt: Make RT capacity-aware") Signed-off-by: Qais Yousef <qais.yousef@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20200716110347.19553-2-qais.yousef@arm.com
2020-06-15sched/deadline: Impose global limits on sched_attr::sched_periodPeter Zijlstra1-0/+14
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20190726161357.397880775@infradead.org
2020-06-08kernel/sysctl.c: ignore out-of-range taint bits introduced via kernel.taintedRafael Aquini1-3/+2
Users with SYS_ADMIN capability can add arbitrary taint flags to the running kernel by writing to /proc/sys/kernel/tainted or issuing the command 'sysctl -w kernel.tainted=...'. This interface, however, is open for any integer value and this might cause an invalid set of flags being committed to the tainted_mask bitset. This patch introduces a simple way for proc_taint() to ignore any eventual invalid bit coming from the user input before committing those bits to the kernel tainted_mask. Signed-off-by: Rafael Aquini <aquini@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Luis Chamberlain <mcgrof@kernel.org> Cc: Kees Cook <keescook@chromium.org> Cc: Iurii Zaikin <yzaikin@google.com> Cc: "Theodore Ts'o" <tytso@mit.edu> Link: http://lkml.kernel.org/r/20200512223946.888020-1-aquini@redhat.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-08panic: add sysctl to dump all CPUs backtraces on oops eventGuilherme G. Piccoli1-0/+11
Usually when the kernel reaches an oops condition, it's a point of no return; in case not enough debug information is available in the kernel splat, one of the last resorts would be to collect a kernel crash dump and analyze it. The problem with this approach is that in order to collect the dump, a panic is required (to kexec-load the crash kernel). When in an environment of multiple virtual machines, users may prefer to try living with the oops, at least until being able to properly shutdown their VMs / finish their important tasks. This patch implements a way to collect a bit more debug details when an oops event is reached, by printing all the CPUs backtraces through the usage of NMIs (on architectures that support that). The sysctl added (and documented) here was called "oops_all_cpu_backtrace", and when set will (as the name suggests) dump all CPUs backtraces. Far from ideal, this may be the last option though for users that for some reason cannot panic on oops. Most of times oopses are clear enough to indicate the kernel portion that must be investigated, but in virtual environments it's possible to observe hypervisor/KVM issues that could lead to oopses shown in other guests CPUs (like virtual APIC crashes). This patch hence aims to help debug such complex issues without resorting to kdump. Signed-off-by: Guilherme G. Piccoli <gpiccoli@canonical.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Kees Cook <keescook@chromium.org> Cc: Luis Chamberlain <mcgrof@kernel.org> Cc: Iurii Zaikin <yzaikin@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Matthew Wilcox <willy@infradead.org> Link: http://lkml.kernel.org/r/20200327224116.21030-1-gpiccoli@canonical.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-08kernel/hung_task.c: introduce sysctl to print all traces when a hung task is ↵Guilherme G. Piccoli1-0/+11
detected Commit 401c636a0eeb ("kernel/hung_task.c: show all hung tasks before panic") introduced a change in that we started to show all CPUs backtraces when a hung task is detected _and_ the sysctl/kernel parameter "hung_task_panic" is set. The idea is good, because usually when observing deadlocks (that may lead to hung tasks), the culprit is another task holding a lock and not necessarily the task detected as hung. The problem with this approach is that dumping backtraces is a slightly expensive task, specially printing that on console (and specially in many CPU machines, as servers commonly found nowadays). So, users that plan to collect a kdump to investigate the hung tasks and narrow down the deadlock definitely don't need the CPUs backtrace on dmesg/console, which will delay the panic and pollute the log (crash tool would easily grab all CPUs traces with 'bt -a' command). Also, there's the reciprocal scenario: some users may be interested in seeing the CPUs backtraces but not have the system panic when a hung task is detected. The current approach hence is almost as embedding a policy in the kernel, by forcing the CPUs backtraces' dump (only) on hung_task_panic. This patch decouples the panic event on hung task from the CPUs backtraces dump, by creating (and documenting) a new sysctl called "hung_task_all_cpu_backtrace", analog to the approach taken on soft/hard lockups, that have both a panic and an "all_cpu_backtrace" sysctl to allow individual control. The new mechanism for dumping the CPUs backtraces on hung task detection respects "hung_task_warnings" by not dumping the traces in case there's no warnings left. Signed-off-by: Guilherme G. Piccoli <gpiccoli@canonical.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Kees Cook <keescook@chromium.org> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Link: http://lkml.kernel.org/r/20200327223646.20779-1-gpiccoli@canonical.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-08kernel: add panic_on_taintRafael Aquini1-1/+10
Analogously to the introduction of panic_on_warn, this patch introduces a kernel option named panic_on_taint in order to provide a simple and generic way to stop execution and catch a coredump when the kernel gets tainted by any given flag. This is useful for debugging sessions as it avoids having to rebuild the kernel to explicitly add calls to panic() into the code sites that introduce the taint flags of interest. For instance, if one is interested in proceeding with a post-mortem analysis at the point a given code path is hitting a bad page (i.e. unaccount_page_cache_page(), or slab_bug()), a coredump can be collected by rebooting the kernel with 'panic_on_taint=0x20' amended to the command line. Another, perhaps less frequent, use for this option would be as a means for assuring a security policy case where only a subset of taints, or no single taint (in paranoid mode), is allowed for the running system. The optional switch 'nousertaint' is handy in this particular scenario, as it will avoid userspace induced crashes by writes to sysctl interface /proc/sys/kernel/tainted causing false positive hits for such policies. [akpm@linux-foundation.org: tweak kernel-parameters.txt wording] Suggested-by: Qian Cai <cai@lca.pw> Signed-off-by: Rafael Aquini <aquini@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Luis Chamberlain <mcgrof@kernel.org> Cc: Dave Young <dyoung@redhat.com> Cc: Baoquan He <bhe@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Kees Cook <keescook@chromium.org> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Adrian Bunk <bunk@kernel.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Laura Abbott <labbott@redhat.com> Cc: Jeff Mahoney <jeffm@suse.com> Cc: Jiri Kosina <jikos@kernel.org> Cc: Takashi Iwai <tiwai@suse.de> Link: http://lkml.kernel.org/r/20200515175502.146720-1-aquini@redhat.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-03Merge branch 'akpm' (patches from Andrew)Linus Torvalds1-1/+2
Merge more updates from Andrew Morton: "More mm/ work, plenty more to come Subsystems affected by this patch series: slub, memcg, gup, kasan, pagealloc, hugetlb, vmscan, tools, mempolicy, memblock, hugetlbfs, thp, mmap, kconfig" * akpm: (131 commits) arm64: mm: use ARCH_HAS_DEBUG_WX instead of arch defined x86: mm: use ARCH_HAS_DEBUG_WX instead of arch defined riscv: support DEBUG_WX mm: add DEBUG_WX support drivers/base/memory.c: cache memory blocks in xarray to accelerate lookup mm/thp: rename pmd_mknotpresent() as pmd_mkinvalid() powerpc/mm: drop platform defined pmd_mknotpresent() mm: thp: don't need to drain lru cache when splitting and mlocking THP hugetlbfs: get unmapped area below TASK_UNMAPPED_BASE for hugetlbfs sparc32: register memory occupied by kernel as memblock.memory include/linux/memblock.h: fix minor typo and unclear comment mm, mempolicy: fix up gup usage in lookup_node tools/vm/page_owner_sort.c: filter out unneeded line mm: swap: memcg: fix memcg stats for huge pages mm: swap: fix vmstats for huge pages mm: vmscan: limit the range of LRU type balancing mm: vmscan: reclaim writepage is IO cost mm: vmscan: determine anon/file pressure balance at the reclaim root mm: balance LRU lists based on relative thrashing mm: only count actual rotations as LRU reclaim cost ...
2020-06-03mm: allow swappiness that prefers reclaiming anon over the file workingsetJohannes Weiner1-1/+2
With the advent of fast random IO devices (SSDs, PMEM) and in-memory swap devices such as zswap, it's possible for swap to be much faster than filesystems, and for swapping to be preferable over thrashing filesystem caches. Allow setting swappiness - which defines the rough relative IO cost of cache misses between page cache and swap-backed pages - to reflect such situations by making the swap-preferred range configurable. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Rik van Riel <riel@surriel.com> Link: http://lkml.kernel.org/r/20200520232525.798933-4-hannes@cmpxchg.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-03Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-nextLinus Torvalds1-1578/+1479
Pull networking updates from David Miller: 1) Allow setting bluetooth L2CAP modes via socket option, from Luiz Augusto von Dentz. 2) Add GSO partial support to igc, from Sasha Neftin. 3) Several cleanups and improvements to r8169 from Heiner Kallweit. 4) Add IF_OPER_TESTING link state and use it when ethtool triggers a device self-test. From Andrew Lunn. 5) Start moving away from custom driver versions, use the globally defined kernel version instead, from Leon Romanovsky. 6) Support GRO vis gro_cells in DSA layer, from Alexander Lobakin. 7) Allow hard IRQ deferral during NAPI, from Eric Dumazet. 8) Add sriov and vf support to hinic, from Luo bin. 9) Support Media Redundancy Protocol (MRP) in the bridging code, from Horatiu Vultur. 10) Support netmap in the nft_nat code, from Pablo Neira Ayuso. 11) Allow UDPv6 encapsulation of ESP in the ipsec code, from Sabrina Dubroca. Also add ipv6 support for espintcp. 12) Lots of ReST conversions of the networking documentation, from Mauro Carvalho Chehab. 13) Support configuration of ethtool rxnfc flows in bcmgenet driver, from Doug Berger. 14) Allow to dump cgroup id and filter by it in inet_diag code, from Dmitry Yakunin. 15) Add infrastructure to export netlink attribute policies to userspace, from Johannes Berg. 16) Several optimizations to sch_fq scheduler, from Eric Dumazet. 17) Fallback to the default qdisc if qdisc init fails because otherwise a packet scheduler init failure will make a device inoperative. From Jesper Dangaard Brouer. 18) Several RISCV bpf jit optimizations, from Luke Nelson. 19) Correct the return type of the ->ndo_start_xmit() method in several drivers, it's netdev_tx_t but many drivers were using 'int'. From Yunjian Wang. 20) Add an ethtool interface for PHY master/slave config, from Oleksij Rempel. 21) Add BPF iterators, from Yonghang Song. 22) Add cable test infrastructure, including ethool interfaces, from Andrew Lunn. Marvell PHY driver is the first to support this facility. 23) Remove zero-length arrays all over, from Gustavo A. R. Silva. 24) Calculate and maintain an explicit frame size in XDP, from Jesper Dangaard Brouer. 25) Add CAP_BPF, from Alexei Starovoitov. 26) Support terse dumps in the packet scheduler, from Vlad Buslov. 27) Support XDP_TX bulking in dpaa2 driver, from Ioana Ciornei. 28) Add devm_register_netdev(), from Bartosz Golaszewski. 29) Minimize qdisc resets, from Cong Wang. 30) Get rid of kernel_getsockopt and kernel_setsockopt in order to eliminate set_fs/get_fs calls. From Christoph Hellwig. * git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (2517 commits) selftests: net: ip_defrag: ignore EPERM net_failover: fixed rollback in net_failover_open() Revert "tipc: Fix potential tipc_aead refcnt leak in tipc_crypto_rcv" Revert "tipc: Fix potential tipc_node refcnt leak in tipc_rcv" vmxnet3: allow rx flow hash ops only when rss is enabled hinic: add set_channels ethtool_ops support selftests/bpf: Add a default $(CXX) value tools/bpf: Don't use $(COMPILE.c) bpf, selftests: Use bpf_probe_read_kernel s390/bpf: Use bcr 0,%0 as tail call nop filler s390/bpf: Maintain 8-byte stack alignment selftests/bpf: Fix verifier test selftests/bpf: Fix sample_cnt shared between two threads bpf, selftests: Adapt cls_redirect to call csum_level helper bpf: Add csum_level helper for fixing up csum levels bpf: Fix up bpf_skb_adjust_room helper's skb csum setting sfc: add missing annotation for efx_ef10_try_update_nic_stats_vf() crypto/chtls: IPv6 support for inline TLS Crypto/chcr: Fixes a coccinile check error Crypto/chcr: Fixes compilations warnings ...
2020-05-10parisc: add sysctl file interface panic_on_stackoverflowXiaoming Ni1-9/+11
The variable sysctl_panic_on_stackoverflow is used in arch/parisc/kernel/irq.c and arch/x86/kernel/irq_32.c, but the sysctl file interface panic_on_stackoverflow only exists on x86. Add sysctl file interface panic_on_stackoverflow for parisc Signed-off-by: Xiaoming Ni <nixiaoming@huawei.com> Reviewed-by: Luis Chamberlain <mcgrof@kernel.org> Signed-off-by: Helge Deller <deller@gmx.de>
2020-05-05sysctl: Fix unused function warningArnd Bergmann1-1/+1
The newly added bpf_stats_handler function has the wrong #ifdef check around it, leading to an unused-function warning when CONFIG_SYSCTL is disabled: kernel/sysctl.c:205:12: error: unused function 'bpf_stats_handler' [-Werror,-Wunused-function] static int bpf_stats_handler(struct ctl_table *table, int write, Fix the check to match the reference. Fixes: d46edd671a14 ("bpf: Sharing bpf runtime stats with BPF_ENABLE_STATS") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Reviewed-by: Luis Chamberlain <mcgrof@kernel.org> Acked-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Song Liu <songliubraving@fb.com> Link: https://lore.kernel.org/bpf/20200505140734.503701-1-arnd@arndb.de
2020-05-01bpf: Sharing bpf runtime stats with BPF_ENABLE_STATSSong Liu1-1/+35
Currently, sysctl kernel.bpf_stats_enabled controls BPF runtime stats. Typical userspace tools use kernel.bpf_stats_enabled as follows: 1. Enable kernel.bpf_stats_enabled; 2. Check program run_time_ns; 3. Sleep for the monitoring period; 4. Check program run_time_ns again, calculate the difference; 5. Disable kernel.bpf_stats_enabled. The problem with this approach is that only one userspace tool can toggle this sysctl. If multiple tools toggle the sysctl at the same time, the measurement may be inaccurate. To fix this problem while keep backward compatibility, introduce a new bpf command BPF_ENABLE_STATS. On success, this command enables stats and returns a valid fd. BPF_ENABLE_STATS takes argument "type". Currently, only one type, BPF_STATS_RUN_TIME, is supported. We can extend the command to support other types of stats in the future. With BPF_ENABLE_STATS, user space tool would have the following flow: 1. Get a fd with BPF_ENABLE_STATS, and make sure it is valid; 2. Check program run_time_ns; 3. Sleep for the monitoring period; 4. Check program run_time_ns again, calculate the difference; 5. Close the fd. Signed-off-by: Song Liu <songliubraving@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200430071506.1408910-2-songliubraving@fb.com
2020-04-27sysctl: pass kernel pointers to ->proc_handlerChristoph Hellwig1-148/+91
Instead of having all the sysctl handlers deal with user pointers, which is rather hairy in terms of the BPF interaction, copy the input to and from userspace in common code. This also means that the strings are always NUL-terminated by the common code, making the API a little bit safer. As most handler just pass through the data to one of the common handlers a lot of the changes are mechnical. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Andrey Ignatov <rdna@fb.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-04-27sysctl: avoid forward declarationsChristoph Hellwig1-1534/+1497
Move the sysctl tables to the end of the file to avoid lots of pointless forward declarations. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-04-27sysctl: remove all extern declaration from sysctl.cChristoph Hellwig1-42/+3
Extern declarations in .c files are a bad style and can lead to mismatches. Use existing definitions in headers where they exist, and otherwise move the external declarations to suitable header files. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-04-27mm: remove watermark_boost_factor_sysctl_handlerChristoph Hellwig1-1/+1
watermark_boost_factor_sysctl_handler is just a pointless wrapper for proc_dointvec_minmax, so remove it and use proc_dointvec_minmax directly. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-04-02mm/compaction: Disable compact_unevictable_allowed on RTSebastian Andrzej Siewior1-1/+28
Since commit 5bbe3547aa3ba ("mm: allow compaction of unevictable pages") it is allowed to examine mlocked pages and compact them by default. On -RT even minor pagefaults are problematic because it may take a few 100us to resolve them and until then the task is blocked. Make compact_unevictable_allowed = 0 default and issue a warning on RT if it is changed. [bigeasy@linutronix.de: v5] Link: https://lore.kernel.org/linux-mm/20190710144138.qyn4tuttdq6h7kqx@linutronix.de/ Link: http://lkml.kernel.org/r/20200319165536.ovi75tsr2seared4@linutronix.de Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Luis Chamberlain <mcgrof@kernel.org> Cc: Kees Cook <keescook@chromium.org> Cc: Iurii Zaikin <yzaikin@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Link: https://lore.kernel.org/linux-mm/20190710144138.qyn4tuttdq6h7kqx@linutronix.de/ Link: http://lkml.kernel.org/r/20200303202225.nhqc3v5gwlb7x6et@linutronix.de Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-04-02mm/compaction: really limit compact_unevictable_allowed to 0 and 1Sebastian Andrzej Siewior1-1/+1
The proc file `compact_unevictable_allowed' should allow 0 and 1 only, the `extra*' attribues have been set properly but without proc_dointvec_minmax() as the `proc_handler' the limit will not be enforced. Use proc_dointvec_minmax() as the `proc_handler' to enfoce the valid specified range. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Luis Chamberlain <mcgrof@kernel.org> Cc: Kees Cook <keescook@chromium.org> Cc: Iurii Zaikin <yzaikin@google.com> Cc: Mel Gorman <mgorman@techsingularity.net> Link: http://lkml.kernel.org/r/20200303202054.gsosv7fsx2ma3cic@linutronix.de Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-03-07sysctl/sysrq: Remove __sysrq_enabled copyDmitry Safonov1-19/+22
Many embedded boards have a disconnected TTL level serial which can generate some garbage that can lead to spurious false sysrq detects. Currently, sysrq can be either completely disabled for serial console or always disabled (with CONFIG_MAGIC_SYSRQ_SERIAL), since commit 732dbf3a6104 ("serial: do not accept sysrq characters via serial port") At Arista, we have such boards that can generate BREAK and random garbage. While disabling sysrq for serial console would solve the problem with spurious false sysrq triggers, it's also desirable to have a way to enable sysrq back. Having the way to enable sysrq was beneficial to debug lockups with a manual investigation in field and on the other side preventing false sysrq detections. As a preparation to add sysrq_toggle_support() call into uart, remove a private copy of sysrq_enabled from sysctl - it should reflect the actual status of sysrq. Furthermore, the private copy isn't correct already in case sysrq_always_enabled is true. So, remove __sysrq_enabled and use a getter-helper sysrq_mask() to check sysrq_key_op enabled status. Cc: Iurii Zaikin <yzaikin@google.com> Cc: Jiri Slaby <jslaby@suse.com> Cc: Luis Chamberlain <mcgrof@kernel.org> Cc: Kees Cook <keescook@chromium.org> Cc: linux-fsdevel@vger.kernel.org Signed-off-by: Dmitry Safonov <dima@arista.com> Link: https://lore.kernel.org/r/20200302175135.269397-2-dima@arista.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-19s390: remove obsolete ieee_emulation_warningsStephen Kitt1-9/+0
s390 math emulation was removed with commit 5a79859ae0f3 ("s390: remove 31 bit support"), rendering ieee_emulation_warnings useless. The code still built because it was protected by CONFIG_MATHEMU, which was no longer selectable. This patch removes the sysctl_ieee_emulation_warnings declaration and the sysctl entry declaration. Link: https://lkml.kernel.org/r/20200214172628.3598516-1-steve@sk2.org Reviewed-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Stephen Kitt <steve@sk2.org> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>