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2019-07-17Merge branch 'akpm' (patches from Andrew)Linus Torvalds1-2/+2
Merge more updates from Andrew Morton: "VM: - z3fold fixes and enhancements by Henry Burns and Vitaly Wool - more accurate reclaimed slab caches calculations by Yafang Shao - fix MAP_UNINITIALIZED UAPI symbol to not depend on config, by Christoph Hellwig - !CONFIG_MMU fixes by Christoph Hellwig - new novmcoredd parameter to omit device dumps from vmcore, by Kairui Song - new test_meminit module for testing heap and pagealloc initialization, by Alexander Potapenko - ioremap improvements for huge mappings, by Anshuman Khandual - generalize kprobe page fault handling, by Anshuman Khandual - device-dax hotplug fixes and improvements, by Pavel Tatashin - enable synchronous DAX fault on powerpc, by Aneesh Kumar K.V - add pte_devmap() support for arm64, by Robin Murphy - unify locked_vm accounting with a helper, by Daniel Jordan - several misc fixes core/lib: - new typeof_member() macro including some users, by Alexey Dobriyan - make BIT() and GENMASK() available in asm, by Masahiro Yamada - changed LIST_POISON2 on x86_64 to 0xdead000000000122 for better code generation, by Alexey Dobriyan - rbtree code size optimizations, by Michel Lespinasse - convert struct pid count to refcount_t, by Joel Fernandes get_maintainer.pl: - add --no-moderated switch to skip moderated ML's, by Joe Perches misc: - ptrace PTRACE_GET_SYSCALL_INFO interface - coda updates - gdb scripts, various" [ Using merge message suggestion from Vlastimil Babka, with some editing - Linus ] * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (100 commits) fs/select.c: use struct_size() in kmalloc() mm: add account_locked_vm utility function arm64: mm: implement pte_devmap support mm: introduce ARCH_HAS_PTE_DEVMAP mm: clean up is_device_*_page() definitions mm/mmap: move common defines to mman-common.h mm: move MAP_SYNC to asm-generic/mman-common.h device-dax: "Hotremove" persistent memory that is used like normal RAM mm/hotplug: make remove_memory() interface usable device-dax: fix memory and resource leak if hotplug fails include/linux/lz4.h: fix spelling and copy-paste errors in documentation ipc/mqueue.c: only perform resource calculation if user valid include/asm-generic/bug.h: fix "cut here" for WARN_ON for __WARN_TAINT architectures scripts/gdb: add helpers to find and list devices scripts/gdb: add lx-genpd-summary command drivers/pps/pps.c: clear offset flags in PPS_SETPARAMS ioctl kernel/pid.c: convert struct pid count to refcount_t drivers/rapidio/devices/rio_mport_cdev.c: NUL terminate some strings select: shift restore_saved_sigmask_unless() into poll_select_copy_remaining() select: change do_poll() to return -ERESTARTNOHAND rather than -EINTR ...
2019-07-16init/Kconfig: fix neighboring typosKees Cook1-2/+2
This fixes a couple typos I noticed in the slab Kconfig: sacrifies -> sacrifices accellerate -> accelerate Seeing as no other instances of these typos are found elsewhere in the kernel and that I originally added one of the two, I can only assume working on slab must have caused damage to the spelling centers of my brain. Link: http://lkml.kernel.org/r/201905292203.CD000546EB@keescook Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-07-15docs: cgroup-v1: add it to the admin-guide bookMauro Carvalho Chehab1-2/+2
Those files belong to the admin guide, so add them. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
2019-07-15docs: accounting: convert to ReSTMauro Carvalho Chehab1-1/+1
Rename the accounting documentation files to ReST, add an index for them and adjust in order to produce a nice html output via the Sphinx build system. At its new index.rst, let's add a :orphan: while this is not linked to the main index.rst file, in order to avoid build warnings. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
2019-07-12Merge tag 'kbuild-v5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuildLinus Torvalds1-0/+33
Pull Kbuild updates from Masahiro Yamada: - remove headers_{install,check}_all targets - remove unreasonable 'depends on !UML' from CONFIG_SAMPLES - re-implement 'make headers_install' more cleanly - add new header-test-y syntax to compile-test headers - compile-test exported headers to ensure they are compilable in user-space - compile-test headers under include/ to ensure they are self-contained - remove -Waggregate-return, -Wno-uninitialized, -Wno-unused-value flags - add -Werror=unknown-warning-option for Clang - add 128-bit built-in types support to genksyms - fix missed rebuild of modules.builtin - propagate 'No space left on device' error in fixdep to Make - allow Clang to use its integrated assembler - improve some coccinelle scripts - add a new flag KBUILD_ABS_SRCTREE to request Kbuild to use absolute path for $(srctree). - do not ignore errors when compression utility is missing - misc cleanups * tag 'kbuild-v5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (49 commits) kbuild: use -- separater intead of $(filter-out ...) for cc-cross-prefix kbuild: Inform user to pass ARCH= for make mrproper kbuild: fix compression errors getting ignored kbuild: add a flag to force absolute path for srctree kbuild: replace KBUILD_SRCTREE with boolean building_out_of_srctree kbuild: remove src and obj from the top Makefile scripts/tags.sh: remove unused environment variables from comments scripts/tags.sh: drop SUBARCH support for ARM kbuild: compile-test kernel headers to ensure they are self-contained kheaders: include only headers into kheaders_data.tar.xz kheaders: remove meaningless -R option of 'ls' kbuild: support header-test-pattern-y kbuild: do not create wrappers for header-test-y kbuild: compile-test exported headers to ensure they are self-contained init/Kconfig: add CONFIG_CC_CAN_LINK kallsyms: exclude kasan local symbols on s390 kbuild: add more hints about SUBDIRS replacement coccinelle: api/stream_open: treat all wait_.*() calls as blocking coccinelle: put_device: Add a cast to an expression for an assignment coccinelle: put_device: Adjust a message construction ...
2019-07-09Merge tag 'docs-5.3' of git://git.lwn.net/linuxLinus Torvalds1-3/+3
Pull Documentation updates from Jonathan Corbet: "It's been a relatively busy cycle for docs: - A fair pile of RST conversions, many from Mauro. These create more than the usual number of simple but annoying merge conflicts with other trees, unfortunately. He has a lot more of these waiting on the wings that, I think, will go to you directly later on. - A new document on how to use merges and rebases in kernel repos, and one on Spectre vulnerabilities. - Various improvements to the build system, including automatic markup of function() references because some people, for reasons I will never understand, were of the opinion that :c:func:``function()`` is unattractive and not fun to type. - We now recommend using sphinx 1.7, but still support back to 1.4. - Lots of smaller improvements, warning fixes, typo fixes, etc" * tag 'docs-5.3' of git://git.lwn.net/linux: (129 commits) docs: automarkup.py: ignore exceptions when seeking for xrefs docs: Move binderfs to admin-guide Disable Sphinx SmartyPants in HTML output doc: RCU callback locks need only _bh, not necessarily _irq docs: format kernel-parameters -- as code Doc : doc-guide : Fix a typo platform: x86: get rid of a non-existent document Add the RCU docs to the core-api manual Documentation: RCU: Add TOC tree hooks Documentation: RCU: Rename txt files to rst Documentation: RCU: Convert RCU UP systems to reST Documentation: RCU: Convert RCU linked list to reST Documentation: RCU: Convert RCU basic concepts to reST docs: filesystems: Remove uneeded .rst extension on toctables scripts/sphinx-pre-install: fix out-of-tree build docs: zh_CN: submitting-drivers.rst: Remove a duplicated Documentation/ Documentation: PGP: update for newer HW devices Documentation: Add section about CPU vulnerabilities for Spectre Documentation: platform: Delete x86-laptop-drivers.txt docs: Note that :c:func: should no longer be used ...
2019-07-09Merge tag 'for-5.3/block-20190708' of git://git.kernel.dk/linux-blockLinus Torvalds1-8/+0
Pull block updates from Jens Axboe: "This is the main block updates for 5.3. Nothing earth shattering or major in here, just fixes, additions, and improvements all over the map. This contains: - Series of documentation fixes (Bart) - Optimization of the blk-mq ctx get/put (Bart) - null_blk removal race condition fix (Bob) - req/bio_op() cleanups (Chaitanya) - Series cleaning up the segment accounting, and request/bio mapping (Christoph) - Series cleaning up the page getting/putting for bios (Christoph) - block cgroup cleanups and moving it to where it is used (Christoph) - block cgroup fixes (Tejun) - Series of fixes and improvements to bcache, most notably a write deadlock fix (Coly) - blk-iolatency STS_AGAIN and accounting fixes (Dennis) - Series of improvements and fixes to BFQ (Douglas, Paolo) - debugfs_create() return value check removal for drbd (Greg) - Use struct_size(), where appropriate (Gustavo) - Two lighnvm fixes (Heiner, Geert) - MD fixes, including a read balance and corruption fix (Guoqing, Marcos, Xiao, Yufen) - block opal shadow mbr additions (Jonas, Revanth) - sbitmap compare-and-exhange improvemnts (Pavel) - Fix for potential bio->bi_size overflow (Ming) - NVMe pull requests: - improved PCIe suspent support (Keith Busch) - error injection support for the admin queue (Akinobu Mita) - Fibre Channel discovery improvements (James Smart) - tracing improvements including nvmetc tracing support (Minwoo Im) - misc fixes and cleanups (Anton Eidelman, Minwoo Im, Chaitanya Kulkarni)" - Various little fixes and improvements to drivers and core" * tag 'for-5.3/block-20190708' of git://git.kernel.dk/linux-block: (153 commits) blk-iolatency: fix STS_AGAIN handling block: nr_phys_segments needs to be zero for REQ_OP_WRITE_ZEROES blk-mq: simplify blk_mq_make_request() blk-mq: remove blk_mq_put_ctx() sbitmap: Replace cmpxchg with xchg block: fix .bi_size overflow block: sed-opal: check size of shadow mbr block: sed-opal: ioctl for writing to shadow mbr block: sed-opal: add ioctl for done-mark of shadow mbr block: never take page references for ITER_BVEC direct-io: use bio_release_pages in dio_bio_complete block_dev: use bio_release_pages in bio_unmap_user block_dev: use bio_release_pages in blkdev_bio_end_io iomap: use bio_release_pages in iomap_dio_bio_end_io block: use bio_release_pages in bio_map_user_iov block: use bio_release_pages in bio_unmap_user block: optionally mark pages dirty in bio_release_pages block: move the BIO_NO_PAGE_REF check into bio_release_pages block: skd_main.c: Remove call to memset after dma_alloc_coherent block: mtip32xx: Remove call to memset after dma_alloc_coherent ...
2019-07-09kbuild: compile-test kernel headers to ensure they are self-containedMasahiro Yamada1-0/+11
The headers in include/ are globally used in the kernel source tree to provide common APIs. They are included from external modules, too. It will be useful to make as many headers self-contained as possible so that we do not have to rely on a specific include order. There are more than 4000 headers in include/. In my rough analysis, 70% of them are already self-contained. With efforts, most of them can be self-contained. For now, we must exclude more than 1000 headers just because they cannot be compiled as standalone units. I added them to header-test-. The blacklist was mostly generated by a script, so the reason of the breakage should be checked later. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Tested-by: Jani Nikula <jani.nikula@intel.com> Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
2019-07-08Merge branch 'for-5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroupLinus Torvalds1-1/+1
Pull cgroup updates from Tejun Heo: "Documentation updates and the addition of cgroup_parse_float() which will be used by new controllers including blk-iocost" * 'for-5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: docs: cgroup-v1: convert docs to ReST and rename to *.rst cgroup: Move cgroup_parse_float() implementation out of CONFIG_SYSFS cgroup: add cgroup_parse_float()
2019-07-08kbuild: compile-test exported headers to ensure they are self-containedMasahiro Yamada1-0/+10
Multiple people have suggested compile-testing UAPI headers to ensure they can be really included from user-space. "make headers_check" is obviously not enough to catch bugs, and we often leak unresolved references to user-space. Use the new header-test-y syntax to implement it. Please note exported headers are compile-tested with a completely different set of compiler flags. The header search path is set to $(objtree)/usr/include since exported headers should not include unexported ones. We use -std=gnu89 for the kernel space since the kernel code highly depends on GNU extensions. On the other hand, UAPI headers should be written in more standardized C, so they are compiled with -std=c90. This will emit errors if C++ style comments, the keyword 'inline', etc. are used. Please use C style comments (/* ... */), '__inline__', etc. in UAPI headers. There is additional compiler requirement to enable this test because many of UAPI headers include <stdlib.h>, <sys/ioctl.h>, <sys/time.h>, etc. directly or indirectly. You cannot use kernel.org pre-built toolchains [1] since they lack <stdlib.h>. I reused CONFIG_CC_CAN_LINK to check the system header availability. The intention is slightly different, but a compiler that can link userspace programs provide system headers. For now, a lot of headers need to be excluded because they cannot be compiled standalone, but this is a good start point. [1] https://mirrors.edge.kernel.org/pub/tools/crosstool/index.html Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
2019-07-08init/Kconfig: add CONFIG_CC_CAN_LINKMasahiro Yamada1-0/+3
Currently, scripts/cc-can-link.sh is run just for BPFILTER_UMH, but defining CC_CAN_LINK will be useful in other places. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-06-24sched/uclamp: Add CPU's clamp buckets refcountingPatrick Bellasi1-0/+53
Utilization clamping allows to clamp the CPU's utilization within a [util_min, util_max] range, depending on the set of RUNNABLE tasks on that CPU. Each task references two "clamp buckets" defining its minimum and maximum (util_{min,max}) utilization "clamp values". A CPU's clamp bucket is active if there is at least one RUNNABLE tasks enqueued on that CPU and refcounting that bucket. When a task is {en,de}queued {on,from} a rq, the set of active clamp buckets on that CPU can change. If the set of active clamp buckets changes for a CPU a new "aggregated" clamp value is computed for that CPU. This is because each clamp bucket enforces a different utilization clamp value. Clamp values are always MAX aggregated for both util_min and util_max. This ensures that no task can affect the performance of other co-scheduled tasks which are more boosted (i.e. with higher util_min clamp) or less capped (i.e. with higher util_max clamp). A task has: task_struct::uclamp[clamp_id]::bucket_id to track the "bucket index" of the CPU's clamp bucket it refcounts while enqueued, for each clamp index (clamp_id). A runqueue has: rq::uclamp[clamp_id]::bucket[bucket_id].tasks to track how many RUNNABLE tasks on that CPU refcount each clamp bucket (bucket_id) of a clamp index (clamp_id). It also has a: rq::uclamp[clamp_id]::bucket[bucket_id].value to track the clamp value of each clamp bucket (bucket_id) of a clamp index (clamp_id). The rq::uclamp::bucket[clamp_id][] array is scanned every time it's needed to find a new MAX aggregated clamp value for a clamp_id. This operation is required only when it's dequeued the last task of a clamp bucket tracking the current MAX aggregated clamp value. In this case, the CPU is either entering IDLE or going to schedule a less boosted or more clamped task. The expected number of different clamp values configured at build time is small enough to fit the full unordered array into a single cache line, for configurations of up to 7 buckets. Add to struct rq the basic data structures required to refcount the number of RUNNABLE tasks for each clamp bucket. Add also the max aggregation required to update the rq's clamp value at each enqueue/dequeue event. Use a simple linear mapping of clamp values into clamp buckets. Pre-compute and cache bucket_id to avoid integer divisions at enqueue/dequeue time. Signed-off-by: Patrick Bellasi <patrick.bellasi@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alessio Balsini <balsini@android.com> Cc: Dietmar Eggemann <dietmar.eggemann@arm.com> Cc: Joel Fernandes <joelaf@google.com> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Morten Rasmussen <morten.rasmussen@arm.com> Cc: Paul Turner <pjt@google.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Quentin Perret <quentin.perret@arm.com> Cc: Rafael J . Wysocki <rafael.j.wysocki@intel.com> Cc: Steve Muckle <smuckle@google.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Todd Kjos <tkjos@google.com> Cc: Vincent Guittot <vincent.guittot@linaro.org> Cc: Viresh Kumar <viresh.kumar@linaro.org> Link: https://lkml.kernel.org/r/20190621084217.8167-2-patrick.bellasi@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-06-20block: rename CONFIG_DEBUG_BLK_CGROUP to CONFIG_BFQ_CGROUP_DEBUGChristoph Hellwig1-8/+0
This option is entirely bfq specific, give it an appropinquate name. Also make it depend on CONFIG_BFQ_GROUP_IOSCHED in Kconfig, as all the functionality already does so anyway. Acked-by: Tejun Heo <tj@kernel.org> Acked-by: Paolo Valente <paolo.valente@linaro.org> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-06-15kbuild: add support for ensuring headers are self-containedJani Nikula1-0/+9
Sometimes it's useful to be able to explicitly ensure certain headers remain self-contained, i.e. that they are compilable as standalone units, by including and/or forward declaring everything they depend on. Add special target header-test-y where individual Makefiles can add headers to be tested if CONFIG_HEADER_TEST is enabled. This will generate a dummy C file per header that gets built as part of extra-y. Signed-off-by: Jani Nikula <jani.nikula@intel.com> Reviewed-by: Sam Ravnborg <sam@ravnborg.org> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-06-14docs: scheduler: convert docs to ReST and rename to *.rstMauro Carvalho Chehab1-3/+3
In order to prepare to add them to the Kernel API book, convert the files to ReST format. The conversion is actually: - add blank lines and identation in order to identify paragraphs; - fix tables markups; - add some lists markups; - mark literal blocks; - adjust title markups. At its new index.rst, let's add a :orphan: while this is not linked to the main index.rst file, in order to avoid build warnings. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-06-14docs: cgroup-v1: convert docs to ReST and rename to *.rstMauro Carvalho Chehab1-1/+1
Convert the cgroup-v1 files to ReST format, in order to allow a later addition to the admin-guide. The conversion is actually: - add blank lines and identation in order to identify paragraphs; - fix tables markups; - add some lists markups; - mark literal blocks; - adjust title markups. At its new index.rst, let's add a :orphan: while this is not linked to the main index.rst file, in order to avoid build warnings. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Tejun Heo <tj@kernel.org>
2019-06-08Merge tag 'char-misc-5.2-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-miscLinus Torvalds1-9/+8
Pull char/misc driver fixes from Greg KH: "Here are some small char and misc driver fixes for 5.2-rc4 to resolve a number of reported issues. The most "notable" one here is the kernel headers in proc^Wsysfs fixes. Those changes move the header file info into sysfs and fixes the build issues that you reported. Other than that, a bunch of small habanalabs driver fixes, some fpga driver fixes, and a few other tiny driver fixes. All of these have been in linux-next for a while with no reported issues" * tag 'char-misc-5.2-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: habanalabs: Read upper bits of trace buffer from RWPHI habanalabs: Fix virtual address access via debugfs for 2MB pages fpga: zynqmp-fpga: Correctly handle error pointer habanalabs: fix bug in checking huge page optimization habanalabs: Avoid using a non-initialized MMU cache mutex habanalabs: fix debugfs code uapi/habanalabs: add opcode for enable/disable device debug mode habanalabs: halt debug engines on user process close test_firmware: Use correct snprintf() limit genwqe: Prevent an integer overflow in the ioctl parport: Fix mem leak in parport_register_dev_model fpga: dfl: expand minor range when registering chrdev region fpga: dfl: Add lockdep classes for pdata->lock fpga: dfl: afu: Pass the correct device to dma_mapping_error() fpga: stratix10-soc: fix use-after-free on s10_init() w1: ds2408: Fix typo after 49695ac46861 (reset on output_write retry with readback) kheaders: Do not regenerate archive if config is not changed kheaders: Move from proc to sysfs lkdtm/bugs: Adjust recursion test to avoid elision lkdtm/usercopy: Moves the KERNEL_DS test to non-canonical
2019-05-24kheaders: Move from proc to sysfsJoel Fernandes (Google)1-9/+8
The kheaders archive consisting of the kernel headers used for compiling bpf programs is in /proc. However there is concern that moving it here will make it permanent. Let us move it to /sys/kernel as discussed [1]. [1] https://lore.kernel.org/patchwork/patch/1067310/#1265969 Suggested-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-21treewide: Add SPDX license identifier - Makefile/KconfigThomas Gleixner1-0/+1
Add SPDX license identifiers to all Make/Kconfig files which: - Have no license information of any form These files fall under the project license, GPL v2 only. The resulting SPDX license identifier is: GPL-2.0-only Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-14mm: shuffle initial free memory to improve memory-side-cache utilizationDan Williams1-0/+24
Patch series "mm: Randomize free memory", v10. This patch (of 3): Randomization of the page allocator improves the average utilization of a direct-mapped memory-side-cache. Memory side caching is a platform capability that Linux has been previously exposed to in HPC (high-performance computing) environments on specialty platforms. In that instance it was a smaller pool of high-bandwidth-memory relative to higher-capacity / lower-bandwidth DRAM. Now, this capability is going to be found on general purpose server platforms where DRAM is a cache in front of higher latency persistent memory [1]. Robert offered an explanation of the state of the art of Linux interactions with memory-side-caches [2], and I copy it here: It's been a problem in the HPC space: http://www.nersc.gov/research-and-development/knl-cache-mode-performance-coe/ A kernel module called zonesort is available to try to help: https://software.intel.com/en-us/articles/xeon-phi-software and this abandoned patch series proposed that for the kernel: https://lkml.kernel.org/r/20170823100205.17311-1-lukasz.daniluk@intel.com Dan's patch series doesn't attempt to ensure buffers won't conflict, but also reduces the chance that the buffers will. This will make performance more consistent, albeit slower than "optimal" (which is near impossible to attain in a general-purpose kernel). That's better than forcing users to deploy remedies like: "To eliminate this gradual degradation, we have added a Stream measurement to the Node Health Check that follows each job; nodes are rebooted whenever their measured memory bandwidth falls below 300 GB/s." A replacement for zonesort was merged upstream in commit cc9aec03e58f ("x86/numa_emulation: Introduce uniform split capability"). With this numa_emulation capability, memory can be split into cache sized ("near-memory" sized) numa nodes. A bind operation to such a node, and disabling workloads on other nodes, enables full cache performance. However, once the workload exceeds the cache size then cache conflicts are unavoidable. While HPC environments might be able to tolerate time-scheduling of cache sized workloads, for general purpose server platforms, the oversubscribed cache case will be the common case. The worst case scenario is that a server system owner benchmarks a workload at boot with an un-contended cache only to see that performance degrade over time, even below the average cache performance due to excessive conflicts. Randomization clips the peaks and fills in the valleys of cache utilization to yield steady average performance. Here are some performance impact details of the patches: 1/ An Intel internal synthetic memory bandwidth measurement tool, saw a 3X speedup in a contrived case that tries to force cache conflicts. The contrived cased used the numa_emulation capability to force an instance of the benchmark to be run in two of the near-memory sized numa nodes. If both instances were placed on the same emulated they would fit and cause zero conflicts. While on separate emulated nodes without randomization they underutilized the cache and conflicted unnecessarily due to the in-order allocation per node. 2/ A well known Java server application benchmark was run with a heap size that exceeded cache size by 3X. The cache conflict rate was 8% for the first run and degraded to 21% after page allocator aging. With randomization enabled the rate levelled out at 11%. 3/ A MongoDB workload did not observe measurable difference in cache-conflict rates, but the overall throughput dropped by 7% with randomization in one case. 4/ Mel Gorman ran his suite of performance workloads with randomization enabled on platforms without a memory-side-cache and saw a mix of some improvements and some losses [3]. While there is potentially significant improvement for applications that depend on low latency access across a wide working-set, the performance may be negligible to negative for other workloads. For this reason the shuffle capability defaults to off unless a direct-mapped memory-side-cache is detected. Even then, the page_alloc.shuffle=0 parameter can be specified to disable the randomization on those systems. Outside of memory-side-cache utilization concerns there is potentially security benefit from randomization. Some data exfiltration and return-oriented-programming attacks rely on the ability to infer the location of sensitive data objects. The kernel page allocator, especially early in system boot, has predictable first-in-first out behavior for physical pages. Pages are freed in physical address order when first onlined. Quoting Kees: "While we already have a base-address randomization (CONFIG_RANDOMIZE_MEMORY), attacks against the same hardware and memory layouts would certainly be using the predictability of allocation ordering (i.e. for attacks where the base address isn't important: only the relative positions between allocated memory). This is common in lots of heap-style attacks. They try to gain control over ordering by spraying allocations, etc. I'd really like to see this because it gives us something similar to CONFIG_SLAB_FREELIST_RANDOM but for the page allocator." While SLAB_FREELIST_RANDOM reduces the predictability of some local slab caches it leaves vast bulk of memory to be predictably in order allocated. However, it should be noted, the concrete security benefits are hard to quantify, and no known CVE is mitigated by this randomization. Introduce shuffle_free_memory(), and its helper shuffle_zone(), to perform a Fisher-Yates shuffle of the page allocator 'free_area' lists when they are initially populated with free memory at boot and at hotplug time. Do this based on either the presence of a page_alloc.shuffle=Y command line parameter, or autodetection of a memory-side-cache (to be added in a follow-on patch). The shuffling is done in terms of CONFIG_SHUFFLE_PAGE_ORDER sized free pages where the default CONFIG_SHUFFLE_PAGE_ORDER is MAX_ORDER-1 i.e. 10, 4MB this trades off randomization granularity for time spent shuffling. MAX_ORDER-1 was chosen to be minimally invasive to the page allocator while still showing memory-side cache behavior improvements, and the expectation that the security implications of finer granularity randomization is mitigated by CONFIG_SLAB_FREELIST_RANDOM. The performance impact of the shuffling appears to be in the noise compared to other memory initialization work. This initial randomization can be undone over time so a follow-on patch is introduced to inject entropy on page free decisions. It is reasonable to ask if the page free entropy is sufficient, but it is not enough due to the in-order initial freeing of pages. At the start of that process putting page1 in front or behind page0 still keeps them close together, page2 is still near page1 and has a high chance of being adjacent. As more pages are added ordering diversity improves, but there is still high page locality for the low address pages and this leads to no significant impact to the cache conflict rate. [1]: https://itpeernetwork.intel.com/intel-optane-dc-persistent-memory-operating-modes/ [2]: https://lkml.kernel.org/r/AT5PR8401MB1169D656C8B5E121752FC0F8AB120@AT5PR8401MB1169.NAMPRD84.PROD.OUTLOOK.COM [3]: https://lkml.org/lkml/2018/10/12/309 [dan.j.williams@intel.com: fix shuffle enable] Link: http://lkml.kernel.org/r/154943713038.3858443.4125180191382062871.stgit@dwillia2-desk3.amr.corp.intel.com [cai@lca.pw: fix SHUFFLE_PAGE_ALLOCATOR help texts] Link: http://lkml.kernel.org/r/20190425201300.75650-1-cai@lca.pw Link: http://lkml.kernel.org/r/154899811738.3165233.12325692939590944259.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Qian Cai <cai@lca.pw> Reviewed-by: Kees Cook <keescook@chromium.org> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Keith Busch <keith.busch@intel.com> Cc: Robert Elliott <elliott@hpe.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-05-07Merge tag 'driver-core-5.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-coreLinus Torvalds1-1/+10
Pull driver core/kobject updates from Greg KH: "Here is the "big" set of driver core patches for 5.2-rc1 There are a number of ACPI patches in here as well, as Rafael said they should go through this tree due to the driver core changes they required. They have all been acked by the ACPI developers. There are also a number of small subsystem-specific changes in here, due to some changes to the kobject core code. Those too have all been acked by the various subsystem maintainers. As for content, it's pretty boring outside of the ACPI changes: - spdx cleanups - kobject documentation updates - default attribute groups for kobjects - other minor kobject/driver core fixes All have been in linux-next for a while with no reported issues" * tag 'driver-core-5.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (47 commits) kobject: clean up the kobject add documentation a bit more kobject: Fix kernel-doc comment first line kobject: Remove docstring reference to kset firmware_loader: Fix a typo ("syfs" -> "sysfs") kobject: fix dereference before null check on kobj Revert "driver core: platform: Fix the usage of platform device name(pdev->name)" init/config: Do not select BUILD_BIN2C for IKCONFIG Provide in-kernel headers to make extending kernel easier kobject: Improve doc clarity kobject_init_and_add() kobject: Improve docs for kobject_add/del driver core: platform: Fix the usage of platform device name(pdev->name) livepatch: Replace klp_ktype_patch's default_attrs with groups cpufreq: schedutil: Replace default_attrs field with groups padata: Replace padata_attr_type default_attrs field with groups irqdesc: Replace irq_kobj_type's default_attrs field with groups net-sysfs: Replace ktype default_attrs field with groups block: Replace all ktype default_attrs with groups samples/kobject: Replace foo_ktype's default_attrs field with groups kobject: Add support for default attribute groups to kobj_type driver core: Postpone DMA tear-down until after devres release for probe failure ...
2019-04-29init/config: Do not select BUILD_BIN2C for IKCONFIGJoel Fernandes (Google)1-1/+0
Since commit 13610aa908dc ("kernel/configs: use .incbin directive to embed config_data.gz"), IKCONFIG no longer uses BUILD_BIN2C so prevent it from being selected in Kconfig. Reviewed-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-29Provide in-kernel headers to make extending kernel easierJoel Fernandes (Google)1-0/+10
Introduce in-kernel headers which are made available as an archive through proc (/proc/kheaders.tar.xz file). This archive makes it possible to run eBPF and other tracing programs that need to extend the kernel for tracing purposes without any dependency on the file system having headers. A github PR is sent for the corresponding BCC patch at: https://github.com/iovisor/bcc/pull/2312 On Android and embedded systems, it is common to switch kernels but not have kernel headers available on the file system. Further once a different kernel is booted, any headers stored on the file system will no longer be useful. This is an issue even well known to distros. By storing the headers as a compressed archive within the kernel, we can avoid these issues that have been a hindrance for a long time. The best way to use this feature is by building it in. Several users have a need for this, when they switch debug kernels, they do not want to update the filesystem or worry about it where to store the headers on it. However, the feature is also buildable as a module in case the user desires it not being part of the kernel image. This makes it possible to load and unload the headers from memory on demand. A tracing program can load the module, do its operations, and then unload the module to save kernel memory. The total memory needed is 3.3MB. By having the archive available at a fixed location independent of filesystem dependencies and conventions, all debugging tools can directly refer to the fixed location for the archive, without concerning with where the headers on a typical filesystem which significantly simplifies tooling that needs kernel headers. The code to read the headers is based on /proc/config.gz code and uses the same technique to embed the headers. Other approaches were discussed such as having an in-memory mountable filesystem, but that has drawbacks such as requiring an in-kernel xz decompressor which we don't have today, and requiring usage of 42 MB of kernel memory to host the decompressed headers at anytime. Also this approach is simpler than such approaches. Reviewed-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-19Make anon_inodes unconditionalDavid Howells1-10/+0
Make the anon_inodes facility unconditional so that it can be used by core VFS code and pidfd code. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> [christian@brauner.io: adapt commit message to mention pidfds] Signed-off-by: Christian Brauner <christian@brauner.io>
2019-03-10Merge tag 'kbuild-v5.1' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuildLinus Torvalds1-1/+18
Pull Kbuild updates from Masahiro Yamada: - do not generate unneeded top-level built-in.a - let git ignore O= directory entirely - optimize scripts/kallsyms slightly - exclude DWARF info from *.s regardless of config options - fix GCC toolchain search path for Clang to prepare ld.lld support - do not generate modules.order when CONFIG_MODULES is disabled - simplify single target rules and remove VPATH for external module build - allow to add optional flags to dpkg-buildpackage when building deb-pkg - move some compiler option tests from Makefile to Kconfig - various Makefile cleanups * tag 'kbuild-v5.1' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (40 commits) kbuild: remove scripts/basic/% build target kbuild: use -Werror=implicit-... instead of -Werror-implicit-... kbuild: clean up scripts/gcc-version.sh kbuild: remove cc-version macro kbuild: update comment block of scripts/clang-version.sh kbuild: remove commented-out INITRD_COMPRESS kbuild: move -gsplit-dwarf, -gdwarf-4 option tests to Kconfig kbuild: [bin]deb-pkg: add DPKG_FLAGS variable kbuild: move ".config not found!" message from Kconfig to Makefile kbuild: invoke syncconfig if include/config/auto.conf.cmd is missing kbuild: simplify single target rules kbuild: remove empty rules for makefiles kbuild: make -r/-R effective in top Makefile for old Make versions kbuild: move tools_silent to a more relevant place kbuild: compute false-positive -Wmaybe-uninitialized cases in Kconfig kbuild: refactor cc-cross-prefix implementation kbuild: hardcode genksyms path and remove GENKSYMS variable scripts/gdb: refactor rules for symlink creation kbuild: create symlink to vmlinux-gdb.py in scripts_gdb target scripts/gdb: do not descend into scripts/gdb from scripts ...
2019-03-10Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds1-0/+1
Pull timer fix from Thomas Gleixner: "A single fix to prevent a unmet dependencies warning in Kconfig" * 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: time: Make VIRT_CPU_ACCOUNTING_GEN depend on GENERIC_CLOCKEVENTS
2019-03-06time: Make VIRT_CPU_ACCOUNTING_GEN depend on GENERIC_CLOCKEVENTSArnd Bergmann1-0/+1
Moving the CONTEXT_TRACKING Kconfig option into kernel/time/Kconfig added an implicit dependency on the surrounding GENERIC_CLOCKEVENTS option, but this is not always enabled when it is possible to select VIRT_CPU_ACCOUNTING_GEN: WARNING: unmet direct dependencies detected for CONTEXT_TRACKING Depends on [n]: GENERIC_CLOCKEVENTS [=n] Selected by [y]: - VIRT_CPU_ACCOUNTING_GEN [=y] && <choice> && HAVE_CONTEXT_TRACKING [=y] && HAVE_VIRT_CPU_ACCOUNTING_GEN [=y] Platforms without GENERIC_CLOCKEVENTS are rare enough so that corner case can be just ignored. Make it a dependency for VIRT_CPU_ACCOUNTING_GEN to simplify the configuration. Fixes: a4cffdad7314 ("time: Move CONTEXT_TRACKING to kernel/time/Kconfig") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: "Paul E . McKenney" <paulmck@linux.ibm.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Link: https://lkml.kernel.org/r/20190304200202.1163250-1-arnd@arndb.de
2019-03-04kbuild: clean up scripts/gcc-version.shMasahiro Yamada1-1/+1
Now that the Kconfig is the only user of this script, we can drop unneeded code. Remove the -p option, and stop prepending the output with zero, so that Kconfig can directly use the output from this script. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-02-28Add io_uring IO interfaceJens Axboe1-0/+9
The submission queue (SQ) and completion queue (CQ) rings are shared between the application and the kernel. This eliminates the need to copy data back and forth to submit and complete IO. IO submissions use the io_uring_sqe data structure, and completions are generated in the form of io_uring_cqe data structures. The SQ ring is an index into the io_uring_sqe array, which makes it possible to submit a batch of IOs without them being contiguous in the ring. The CQ ring is always contiguous, as completion events are inherently unordered, and hence any io_uring_cqe entry can point back to an arbitrary submission. Two new system calls are added for this: io_uring_setup(entries, params) Sets up an io_uring instance for doing async IO. On success, returns a file descriptor that the application can mmap to gain access to the SQ ring, CQ ring, and io_uring_sqes. io_uring_enter(fd, to_submit, min_complete, flags, sigset, sigsetsize) Initiates IO against the rings mapped to this fd, or waits for them to complete, or both. The behavior is controlled by the parameters passed in. If 'to_submit' is non-zero, then we'll try and submit new IO. If IORING_ENTER_GETEVENTS is set, the kernel will wait for 'min_complete' events, if they aren't already available. It's valid to set IORING_ENTER_GETEVENTS and 'min_complete' == 0 at the same time, this allows the kernel to return already completed events without waiting for them. This is useful only for polling, as for IRQ driven IO, the application can just check the CQ ring without entering the kernel. With this setup, it's possible to do async IO with a single system call. Future developments will enable polled IO with this interface, and polled submission as well. The latter will enable an application to do IO without doing ANY system calls at all. For IRQ driven IO, an application only needs to enter the kernel for completions if it wants to wait for them to occur. Each io_uring is backed by a workqueue, to support buffered async IO as well. We will only punt to an async context if the command would need to wait for IO on the device side. Any data that can be accessed directly in the page cache is done inline. This avoids the slowness issue of usual threadpools, since cached data is accessed as quickly as a sync interface. Sample application: http://git.kernel.dk/cgit/fio/plain/t/io_uring.c Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-02-27kbuild: compute false-positive -Wmaybe-uninitialized cases in KconfigMasahiro Yamada1-0/+17
Since -Wmaybe-uninitialized was introduced by GCC 4.7, we have patched various false positives: - commit e74fc973b6e5 ("Turn off -Wmaybe-uninitialized when building with -Os") turned off this option for -Os. - commit 815eb71e7149 ("Kbuild: disable 'maybe-uninitialized' warning for CONFIG_PROFILE_ALL_BRANCHES") turned off this option for CONFIG_PROFILE_ALL_BRANCHES - commit a76bcf557ef4 ("Kbuild: enable -Wmaybe-uninitialized warning for "make W=1"") turned off this option for GCC < 4.9 Arnd provided more explanation in https://lkml.org/lkml/2017/3/14/903 I think this looks better by shifting the logic from Makefile to Kconfig. Link: https://github.com/ClangBuiltLinux/linux/issues/350 Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Reviewed-by: Nathan Chancellor <natechancellor@gmail.com> Tested-by: Nick Desaulniers <ndesaulniers@google.com>
2019-02-01psi: clarify the Kconfig text for the default-disable optionJohannes Weiner1-0/+11
The current help text caused some confusion in online forums about whether or not to default-enable or default-disable psi in vendor kernels. This is because it doesn't communicate the reason for why we made this setting configurable in the first place: that the overhead is non-zero in an artificial scheduler stress test. Since this isn't representative of real workloads, and the effect was not measurable in scheduler-heavy real world applications such as the webservers and memcache installations at Facebook, it's fair to point out that this is a pretty cautious option to select. Link: http://lkml.kernel.org/r/20190129233617.16767-1-hannes@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-02-01init/Kconfig: fix grammar by moving a closing parenthesisJonathan Neuschäfer1-1/+1
Link: http://lkml.kernel.org/r/20190129150813.15785-1-j.neuschaefer@gmx.net Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-01-14kbuild: Disable LD_DEAD_CODE_DATA_ELIMINATION with ftrace & GCC <= 4.7Paul Burton1-0/+1
When building using GCC 4.7 or older, -ffunction-sections & the -pg flag used by ftrace are incompatible. This causes warnings or build failures (where -Werror applies) such as the following: arch/mips/generic/init.c: error: -ffunction-sections disabled; it makes profiling impossible This used to be taken into account by the ordering of calls to cc-option from within the top-level Makefile, which was introduced by commit 90ad4052e85c ("kbuild: avoid conflict between -ffunction-sections and -pg on gcc-4.7"). Unfortunately this was broken when the CONFIG_LD_DEAD_CODE_DATA_ELIMINATION cc-option check was moved to Kconfig in commit e85d1d65cd8a ("kbuild: test dead code/data elimination support in Kconfig"), because the flags used by this check no longer include -pg. Fix this by not allowing CONFIG_LD_DEAD_CODE_DATA_ELIMINATION to be enabled at the same time as ftrace/CONFIG_FUNCTION_TRACER when building using GCC 4.7 or older. Signed-off-by: Paul Burton <paul.burton@mips.com> Fixes: e85d1d65cd8a ("kbuild: test dead code/data elimination support in Kconfig") Reported-by: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: stable@vger.kernel.org # v4.19+ Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-01-06jump_label: move 'asm goto' support test to KconfigMasahiro Yamada1-0/+3
Currently, CONFIG_JUMP_LABEL just means "I _want_ to use jump label". The jump label is controlled by HAVE_JUMP_LABEL, which is defined like this: #if defined(CC_HAVE_ASM_GOTO) && defined(CONFIG_JUMP_LABEL) # define HAVE_JUMP_LABEL #endif We can improve this by testing 'asm goto' support in Kconfig, then make JUMP_LABEL depend on CC_HAS_ASM_GOTO. Ugly #ifdef HAVE_JUMP_LABEL will go away, and CONFIG_JUMP_LABEL will match to the real kernel capability. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
2018-12-27Merge tag 'audit-pr-20181224' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/auditLinus Torvalds1-9/+0
Pull audit updates from Paul Moore: "In the finest of holiday of traditions, I have a number of gifts to share today. While most of them are re-gifts from others, unlike the typical re-gift, these are things you will want in and around your tree; I promise. This pull request is perhaps a bit larger than our typical PR, but most of it comes from Jan's rework of audit's fanotify code; a very welcome improvement. We ran this through our normal regression tests, as well as some newly created stress tests and everything looks good. Richard added a few patches, mostly cleaning up a few things and and shortening some of the audit records that we send to userspace; a change the userspace folks are quite happy about. Finally YueHaibing and I kick in a few patches to simplify things a bit and make the code less prone to errors. Lastly, I want to say thanks one more time to everyone who has contributed patches, testing, and code reviews for the audit subsystem over the past year. The project is what it is due to your help and contributions - thank you" * tag 'audit-pr-20181224' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit: (22 commits) audit: remove duplicated include from audit.c audit: shorten PATH cap values when zero audit: use current whenever possible audit: minimize our use of audit_log_format() audit: remove WATCH and TREE config options audit: use session_info helper audit: localize audit_log_session_info prototype audit: Use 'mark' name for fsnotify_mark variables audit: Replace chunk attached to mark instead of replacing mark audit: Simplify locking around untag_chunk() audit: Drop all unused chunk nodes during deletion audit: Guarantee forward progress of chunk untagging audit: Allocate fsnotify mark independently of chunk audit: Provide helper for dropping mark's chunk reference audit: Remove pointless check in insert_hash() audit: Factor out chunk replacement code audit: Make hash table insertion safe against concurrent lookups audit: Embed key into chunk audit: Fix possible tagging failures audit: Fix possible spurious -ENOSPC error ...
2018-12-14psi: fix reference to kernel commandline enableBaruch Siach1-2/+2
The kernel commandline parameter named in CONFIG_PSI_DEFAULT_DISABLED help text contradicts the documentation in kernel-parameters.txt, and the code. Fix that. Link: http://lkml.kernel.org/r/20181203213416.GA12627@cmpxchg.org Fixes: e0c274472d ("psi: make disabling/enabling easier for vendor kernels") Signed-off-by: Baruch Siach <baruch@tkos.co.il> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-11-30psi: make disabling/enabling easier for vendor kernelsJohannes Weiner1-0/+9
Mel Gorman reports a hackbench regression with psi that would prohibit shipping the suse kernel with it default-enabled, but he'd still like users to be able to opt in at little to no cost to others. With the current combination of CONFIG_PSI and the psi_disabled bool set from the commandline, this is a challenge. Do the following things to make it easier: 1. Add a config option CONFIG_PSI_DEFAULT_DISABLED that allows distros to enable CONFIG_PSI in their kernel but leave the feature disabled unless a user requests it at boot-time. To avoid double negatives, rename psi_disabled= to psi=. 2. Make psi_disabled a static branch to eliminate any branch costs when the feature is disabled. In terms of numbers before and after this patch, Mel says: : The following is a comparision using CONFIG_PSI=n as a baseline against : your patch and a vanilla kernel : : 4.20.0-rc4 4.20.0-rc4 4.20.0-rc4 : kconfigdisable-v1r1 vanilla psidisable-v1r1 : Amean 1 1.3100 ( 0.00%) 1.3923 ( -6.28%) 1.3427 ( -2.49%) : Amean 3 3.8860 ( 0.00%) 4.1230 * -6.10%* 3.8860 ( -0.00%) : Amean 5 6.8847 ( 0.00%) 8.0390 * -16.77%* 6.7727 ( 1.63%) : Amean 7 9.9310 ( 0.00%) 10.8367 * -9.12%* 9.9910 ( -0.60%) : Amean 12 16.6577 ( 0.00%) 18.2363 * -9.48%* 17.1083 ( -2.71%) : Amean 18 26.5133 ( 0.00%) 27.8833 * -5.17%* 25.7663 ( 2.82%) : Amean 24 34.3003 ( 0.00%) 34.6830 ( -1.12%) 32.0450 ( 6.58%) : Amean 30 40.0063 ( 0.00%) 40.5800 ( -1.43%) 41.5087 ( -3.76%) : Amean 32 40.1407 ( 0.00%) 41.2273 ( -2.71%) 39.9417 ( 0.50%) : : It's showing that the vanilla kernel takes a hit (as the bisection : indicated it would) and that disabling PSI by default is reasonably : close in terms of performance for this particular workload on this : particular machine so; Link: http://lkml.kernel.org/r/20181127165329.GA29728@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Tested-by: Mel Gorman <mgorman@techsingularity.net> Reported-by: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-11-19audit: remove WATCH and TREE config optionsRichard Guy Briggs1-9/+0
Remove the CONFIG_AUDIT_WATCH and CONFIG_AUDIT_TREE config options since they are both dependent on CONFIG_AUDITSYSCALL and force CONFIG_FSNOTIFY. Signed-off-by: Richard Guy Briggs <rgb@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2018-10-26psi: cgroup supportJohannes Weiner1-0/+4
On a system that executes multiple cgrouped jobs and independent workloads, we don't just care about the health of the overall system, but also that of individual jobs, so that we can ensure individual job health, fairness between jobs, or prioritize some jobs over others. This patch implements pressure stall tracking for cgroups. In kernels with CONFIG_PSI=y, cgroup2 groups will have cpu.pressure, memory.pressure, and io.pressure files that track aggregate pressure stall times for only the tasks inside the cgroup. Link: http://lkml.kernel.org/r/20180828172258.3185-10-hannes@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Tejun Heo <tj@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Daniel Drake <drake@endlessm.com> Tested-by: Suren Baghdasaryan <surenb@google.com> Cc: Christopher Lameter <cl@linux.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Johannes Weiner <jweiner@fb.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Enderborg <peter.enderborg@sony.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Shakeel Butt <shakeelb@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>
2018-10-26psi: pressure stall information for CPU, memory, and IOJohannes Weiner1-0/+15
When systems are overcommitted and resources become contended, it's hard to tell exactly the impact this has on workload productivity, or how close the system is to lockups and OOM kills. In particular, when machines work multiple jobs concurrently, the impact of overcommit in terms of latency and throughput on the individual job can be enormous. In order to maximize hardware utilization without sacrificing individual job health or risk complete machine lockups, this patch implements a way to quantify resource pressure in the system. A kernel built with CONFIG_PSI=y creates files in /proc/pressure/ that expose the percentage of time the system is stalled on CPU, memory, or IO, respectively. Stall states are aggregate versions of the per-task delay accounting delays: cpu: some tasks are runnable but not executing on a CPU memory: tasks are reclaiming, or waiting for swapin or thrashing cache io: tasks are waiting for io completions These percentages of walltime can be thought of as pressure percentages, and they give a general sense of system health and productivity loss incurred by resource overcommit. They can also indicate when the system is approaching lockup scenarios and OOMs. To do this, psi keeps track of the task states associated with each CPU and samples the time they spend in stall states. Every 2 seconds, the samples are averaged across CPUs - weighted by the CPUs' non-idle time to eliminate artifacts from unused CPUs - and translated into percentages of walltime. A running average of those percentages is maintained over 10s, 1m, and 5m periods (similar to the loadaverage). [hannes@cmpxchg.org: doc fixlet, per Randy] Link: http://lkml.kernel.org/r/20180828205625.GA14030@cmpxchg.org [hannes@cmpxchg.org: code optimization] Link: http://lkml.kernel.org/r/20180907175015.GA8479@cmpxchg.org [hannes@cmpxchg.org: rename psi_clock() to psi_update_work(), per Peter] Link: http://lkml.kernel.org/r/20180907145404.GB11088@cmpxchg.org [hannes@cmpxchg.org: fix build] Link: http://lkml.kernel.org/r/20180913014222.GA2370@cmpxchg.org Link: http://lkml.kernel.org/r/20180828172258.3185-9-hannes@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Daniel Drake <drake@endlessm.com> Tested-by: Suren Baghdasaryan <surenb@google.com> Cc: Christopher Lameter <cl@linux.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Johannes Weiner <jweiner@fb.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Enderborg <peter.enderborg@sony.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Shakeel Butt <shakeelb@google.com> Cc: Tejun Heo <tj@kernel.org> Cc: Vinayak Menon <vinmenon@codeaurora.org> Cc: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-10-02sched/pelt: Fix warning and clean up IRQ PELT configVincent Guittot1-0/+5
Create a config for enabling irq load tracking in the scheduler. irq load tracking is useful only when irq or paravirtual time is accounted but it's only possible with SMP for now. Also use __maybe_unused to remove the compilation warning in update_rq_clock_task() that has been introduced by: 2e62c4743adc ("sched/fair: Remove #ifdefs from scale_rt_capacity()") Suggested-by: Ingo Molnar <mingo@redhat.com> Reported-by: Dou Liyang <douly.fnst@cn.fujitsu.com> Reported-by: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com> Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: bp@alien8.de Cc: dou_liyang@163.com Fixes: 2e62c4743adc ("sched/fair: Remove #ifdefs from scale_rt_capacity()") Link: http://lkml.kernel.org/r/1537867062-27285-1-git-send-email-vincent.guittot@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-08-25Merge tag 'kbuild-v4.19-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuildLinus Torvalds1-0/+2
Pull more Kbuild updates from Masahiro Yamada: - add build_{menu,n,g,x}config targets for compile-testing Kconfig - fix and improve recursive dependency detection in Kconfig - fix parallel building of menuconfig/nconfig - fix syntax error in clang-version.sh - suppress distracting log from syncconfig - remove obsolete "rpm" target - remove VMLINUX_SYMBOL(_STR) macro entirely - fix microblaze build with CONFIG_DYNAMIC_FTRACE - move compiler test for dead code/data elimination to Kconfig - rename well-known LDFLAGS variable to KBUILD_LDFLAGS - misc fixes and cleanups * tag 'kbuild-v4.19-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: kbuild: rename LDFLAGS to KBUILD_LDFLAGS kbuild: pass LDFLAGS to recordmcount.pl kbuild: test dead code/data elimination support in Kconfig initramfs: move gen_initramfs_list.sh from scripts/ to usr/ vmlinux.lds.h: remove stale <linux/export.h> include export.h: remove VMLINUX_SYMBOL() and VMLINUX_SYMBOL_STR() Coccinelle: remove pci_alloc_consistent semantic to detect in zalloc-simple.cocci kbuild: make sorting initramfs contents independent of locale kbuild: remove "rpm" target, which is alias of "rpm-pkg" kbuild: Fix LOADLIBES rename in Documentation/kbuild/makefiles.txt kconfig: suppress "configuration written to .config" for syncconfig kconfig: fix "Can't open ..." in parallel build kbuild: Add a space after `!` to prevent parsing as file pattern scripts: modpost: check memory allocation results kconfig: improve the recursive dependency report kconfig: report recursive dependency involving 'imply' kconfig: error out when seeing recursive dependency kconfig: add build-only configurator targets scripts/dtc: consolidate include path options in Makefile
2018-08-24kbuild: test dead code/data elimination support in KconfigMasahiro Yamada1-0/+2
This config option should be enabled only when both the compiler and the linker support necessary flags. Add proper dependencies to Kconfig. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-08-22init/Kconfig: remove EXPERT from CHECKPOINT_RESTOREAdrian Reber1-12/+12
The CHECKPOINT_RESTORE configuration option was introduced in 2012 and combined with EXPERT. CHECKPOINT_RESTORE is already enabled in many distribution kernels and also part of the defconfigs of various architectures. To make it easier for distributions to enable CHECKPOINT_RESTORE this removes EXPERT and moves the configuration option out of the EXPERT block. Link: http://lkml.kernel.org/r/20180712130733.11510-1-adrian@lisas.de Signed-off-by: Adrian Reber <adrian@lisas.de> Acked-by: Oleg Nesterov <oleg@redhat.com> Reviewed-by: Hendrik Brueckner <brueckner@linux.ibm.com> Acked-by: Pavel Emelyanov <xemul@virtuozzo.com> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Andrei Vagin <avagin@virtuozzo.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22init/Kconfig: fix its typosRandy Dunlap1-2/+2
Correct typos of "it's" to "its. Link: http://lkml.kernel.org/r/0ac627b6-5527-55f4-0489-1631aa34fc11@infradead.org Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-17mm: introduce CONFIG_MEMCG_KMEM as combination of CONFIG_MEMCG && !CONFIG_SLOBKirill Tkhai1-0/+5
Introduce new config option, which is used to replace repeating CONFIG_MEMCG && !CONFIG_SLOB pattern. Next patches add a little more memcg+kmem related code, so let's keep the defines more clearly. Link: http://lkml.kernel.org/r/153063053670.1818.15013136946600481138.stgit@localhost.localdomain Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com> Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com> Tested-by: Shakeel Butt <shakeelb@google.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Guenter Roeck <linux@roeck-us.net> Cc: "Huang, Ying" <ying.huang@intel.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Josef Bacik <jbacik@fb.com> Cc: Li RongQing <lirongqing@baidu.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Matthias Kaehlcke <mka@chromium.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Michal Hocko <mhocko@kernel.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Philippe Ombredanne <pombredanne@nexb.com> Cc: Roman Gushchin <guro@fb.com> Cc: Sahitya Tummala <stummala@codeaurora.org> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Waiman Long <longman@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-15Merge tag 'kconfig-v4.19-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuildLinus Torvalds1-3/+11
Pull Kconfig consolidation from Masahiro Yamada: "Consolidation of Kconfig files by Christoph Hellwig. Move the source statements of arch-independent Kconfig files instead of duplicating the includes in every arch/$(SRCARCH)/Kconfig" * tag 'kconfig-v4.19-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: kconfig: add a Memory Management options" menu kconfig: move the "Executable file formats" menu to fs/Kconfig.binfmt kconfig: use a menu in arch/Kconfig to reduce clutter kconfig: include kernel/Kconfig.preempt from init/Kconfig Kconfig: consolidate the "Kernel hacking" menu kconfig: include common Kconfig files from top-level Kconfig kconfig: remove duplicate SWAP symbol defintions um: create a proper drivers Kconfig um: cleanup Kconfig files um: stop abusing KBUILD_KCONFIG
2018-08-15Merge tag 'kconfig-v4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuildLinus Torvalds1-2/+2
Pull Kconfig updates from Masahiro Yamada: - show clearer error messages where pkg-config is needed, but not installed - rename SYMBOL_AUTO to SYMBOL_NO_WRITE to reflect its semantics - create all necessary directories by Kconfig tool itself instead of Makefile - update the .config unconditionally when syncconfig is invoked - use 'include' directive instead of '-include' where include/config/{auto,tristate}.conf is mandatory - do not try to update the .config when running install targets - add .DELETE_ON_ERROR to delete partially updated files - misc cleanups and fixes * tag 'kconfig-v4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: kconfig: remove P_ENV property type kconfig: remove unused sym_get_env_prop() function kconfig: fix the rule of mainmenu_stmt symbol init/Kconfig: Use short unix-style option instead of --longname Kbuild: Makefile.modbuiltin: include auto.conf and tristate.conf mandatory kbuild: remove auto.conf from prerequisite of phony targets kbuild: do not update config for 'make kernelrelease' kbuild: do not update config when running install targets kbuild: add .DELETE_ON_ERROR special target kbuild: use 'include' directive to load auto.conf from top Makefile kconfig: allow all config targets to write auto.conf if missing kconfig: make syncconfig update .config regardless of sym_change_count kconfig: create directories needed for syncconfig by itself kconfig: remove unneeded directory generation from local*config kconfig: split out useful helpers in confdata.c kconfig: rename file_write_dep and move it to confdata.c kconfig: fix typos in description of "choice" in kconfig-language.txt kconfig: handle format string before calling conf_message_callback() kconfig: rename SYMBOL_AUTO to SYMBOL_NO_WRITE kconfig: check for pkg-config on make {menu,n,g,x}config
2018-08-15Merge tag 'kbuild-v4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuildLinus Torvalds1-0/+9
Pull Kbuild updates from Masahiro Yamada: - verify depmod is installed before modules_install - support build salt in case build ids must be unique between builds - allow users to specify additional host compiler flags via HOST*FLAGS, and rename internal variables to KBUILD_HOST*FLAGS - update buildtar script to drop vax support, add arm64 support - update builddeb script for better debarch support - document the pit-fall of if_changed usage - fix parallel build of UML with O= option - make 'samples' target depend on headers_install to fix build errors - remove deprecated host-progs variable - add a new coccinelle script for refcount_t vs atomic_t check - improve double-test coccinelle script - misc cleanups and fixes * tag 'kbuild-v4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (41 commits) coccicheck: return proper error code on fail Coccinelle: doubletest: reduce side effect false positives kbuild: remove deprecated host-progs variable kbuild: make samples really depend on headers_install um: clean up archheaders recipe kbuild: add %asm-generic to no-dot-config-targets um: fix parallel building with O= option scripts: Add Python 3 support to tracing/draw_functrace.py builddeb: Add automatic support for sh{3,4}{,eb} architectures builddeb: Add automatic support for riscv* architectures builddeb: Add automatic support for m68k architecture builddeb: Add automatic support for or1k architecture builddeb: Add automatic support for sparc64 architecture builddeb: Add automatic support for mips{,64}r6{,el} architectures builddeb: Add automatic support for mips64el architecture builddeb: Add automatic support for ppc64 and powerpcspe architectures builddeb: Introduce functions to simplify kconfig tests in set_debarch builddeb: Drop check for 32-bit s390 builddeb: Change architecture detection fallback to use dpkg-architecture builddeb: Skip architecture detection when KBUILD_DEBARCH is set ...
2018-08-13Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linuxLinus Torvalds1-1/+14
Pull s390 updates from Heiko Carstens: "Since Martin is on vacation you get the s390 pull request from me: - Host large page support for KVM guests. As the patches have large impact on arch/s390/mm/ this series goes out via both the KVM and the s390 tree. - Add an option for no compression to the "Kernel compression mode" menu, this will come in handy with the rework of the early boot code. - A large rework of the early boot code that will make life easier for KASAN and KASLR. With the rework the bootable uncompressed image is not generated anymore, only the bzImage is available. For debuggung purposes the new "no compression" option is used. - Re-enable the gcc plugins as the issue with the latent entropy plugin is solved with the early boot code rework. - More spectre relates changes: + Detect the etoken facility and remove expolines automatically. + Add expolines to a few more indirect branches. - A rewrite of the common I/O layer trace points to make them consumable by 'perf stat'. - Add support for format-3 PCI function measurement blocks. - Changes for the zcrypt driver: + Add attributes to indicate the load of cards and queues. + Restructure some code for the upcoming AP device support in KVM. - Build flags improvements in various Makefiles. - A few fixes for the kdump support. - A couple of patches for gcc 8 compile warning cleanup. - Cleanup s390 specific proc handlers. - Add s390 support to the restartable sequence self tests. - Some PTR_RET vs PTR_ERR_OR_ZERO cleanup. - Lots of bug fixes" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (107 commits) s390/dasd: fix hanging offline processing due to canceled worker s390/dasd: fix panic for failed online processing s390/mm: fix addressing exception after suspend/resume rseq/selftests: add s390 support s390: fix br_r1_trampoline for machines without exrl s390/lib: use expoline for all bcr instructions s390/numa: move initial setup of node_to_cpumask_map s390/kdump: Fix elfcorehdr size calculation s390/cpum_sf: save TOD clock base in SDBs for time conversion KVM: s390: Add huge page enablement control s390/mm: Add huge page gmap linking support s390/mm: hugetlb pages within a gmap can not be freed KVM: s390: Add skey emulation fault handling s390/mm: Add huge pmd storage key handling s390/mm: Clear skeys for newly mapped huge guest pmds s390/mm: Clear huge page storage keys on enable_skey s390/mm: Add huge page dirty sync support s390/mm: Add gmap pmd invalidation and clearing s390/mm: Add gmap pmd notification bit setting s390/mm: Add gmap pmd linking ...