Commits · 0day-ci/linux

Document libumcg. Signed-off-by: Peter Oskolkov <posk@google.com>

Document User Managed Concurrency Groups syscalls, data structures, state transitions, etc. in UMGG kernel API. Signed-off-by: Peter Oskolkov <posk@google.com>

Implement libumcg in tools/lib/umcg. Define higher-level UMCG API that hides kernel-level UMCG API intricacies. As a higher-level API, libumcg makes subtle changes to server/worker interactions, compared to the kernel UMCG API, and introduces the following new concepts: - UMCG Group: a collection of servers and workers in a process that can interact with each other; UMCG groups are useful to partition servers and workers within a process in order to, for example, affine work to specific NUMA nodes; - UMCG basic tasks: these are UMCG servers, from the kernel point of view; they do not interact with UMCG workers and thus do not need in UMCG groups; used for cooperative wait/wake/swap operations. The main difference of server/worker interaction in libumcg vs the kernel-side UMCG API is that a wakeup can be queued: if umcg_wake() is called on a RUNNING UMCG task, the fact is recorded (in the userspace), and when the task calls umcg_wait() or umcg_swap(), the wakeup is consumed and the task is not marked IDLE. Libumcg exports the following API: umcg_enabled() umcg_get_utid() umcg_set_task_tag() umcg_get_task_tag() umcg_create_group() umcg_destroy_group() umcg_register_basic_task() umcg_register_worker() umcg_register_server() umcg_unregister_task() umcg_wait() umcg_wake() umcg_swap() umcg_get_idle_worker() umcg_run_worker() umcg_preempt_worker() umcg_get_time_ns() See tools/lib/umcg/libumcg.txt for details. Notes: - this is still somewhat work-in-progress: while the kernel side code has been more or less stable over the last couple of months, the userspace side of things is less so; - while libumcg is intended to be the main/primary/only direct user of the kernel UMCG API, at the moment the implementation is more geared more towards testing and correctness than live production usage, with a lot of asserts and similar development helpers; - I have a number of umcg selftests that I plan to clean up and post shortly. Signed-off-by: Peter Oskolkov <posk@google.com>

Define struct umcg_task and two syscalls: sys_umcg_ctl sys_umcg_wait. User Managed Concurrency Groups is an M:N threading toolkit that allows constructing user space schedulers designed to efficiently manage heterogeneous in-process workloads while maintaining high CPU utilization (95%+). In addition, M:N threading and cooperative user space scheduling enables synchronous coding style and better cache locality when compared to asynchronous callback/continuation style of programming. UMCG kernel API is build around the following ideas: * UMCG server: a task/thread representing "kernel threads", or (v)CPUs; * UMCG worker: a task/thread representing "application threads", to be scheduled over servers; * UMCG task state: (NONE), RUNNING, BLOCKED, IDLE: states a UMCG task (a server or a worker) can be in; * UMCG task state flag: LOCKED, PREEMPTED: additional state flags that can be ORed with the task state to communicate additional information to the kernel; * struct umcg_task: a per-task userspace set of data fields, usually residing in the TLS, that fully reflects the current task's UMCG state and controls the way the kernel manages the task; * sys_umcg_ctl(): a syscall used to register the current task/thread as a server or a worker, or to unregister a UMCG task; * sys_umcg_wait(): a syscall used to put the current task to sleep and/or wake another task, pontentially context-switching between the two tasks on-CPU synchronously. In short, servers can be thought of as CPUs over which application threads (workers) are scheduled; at any one time a worker is either: - RUNNING: has a server and is schedulable by the kernel; - BLOCKED: blocked in the kernel (e.g. on I/O, or a futex); - IDLE: is not blocked, but cannot be scheduled by the kernel to run because it has no server assigned to it (e.g. because all available servers are busy "running" other workers). Usually the number of servers in a process is equal to the number of CPUs available to the kernel if the process is supposed to consume the whole machine, or less than the number of CPUs available if the process is sharing the machine with other workloads. The number of workers in a process can grow very large: tens of thousands is normal; hundreds of thousands and more (millions) is something that would be desirable to achieve in the future, as lightweight userspace threads in Java and Go easily scale to millions, and UMCG workers are (intended to be) conceptually similar to those. Detailed use cases and API behavior are provided in Documentation/userspace-api/umcg.txt (see sibling patches). Some high-level implementation notes: UMCG tasks (workers and servers) are "tagged" with struct umcg_task residing in userspace (usually in TLS) to facilitate kernel/userspace communication. This makes the kernel-side code much simpler (see e.g. the implementation of sys_umcg_wait), but also requires some careful uaccess handling and page pinning (see below). The main UMCG server/worker interaction looks like: a. worker W1 is RUNNING, with a server S attached to it sleeping in IDLE state; b. worker W1 blocks in the kernel, e.g. on I/O; c. the kernel marks W1 as BLOCKED, the attached server S as RUNNING, and wakes S (the "block detection" event); d. the server now picks another IDLE worker W2 to run: marks W2 as RUNNING, itself as IDLE, ands calls sys_umcg_wait(); e. when the blocking operation of W1 completes, the worker is marked by the kernel as IDLE and added to idle workers list (see struct umcg_task) for the userspace to pick up and later run (the "wake detection" event). While there are additional operations such as worker-to-worker context switch, preemption, workers "yielding", etc., the "workflow" above is the main worker/server interaction that drives the implementation. Specifically: - most operations are conceptually context switches: - scheduling a worker: a running server goes to sleep and "runs" a worker in its place; - block detection: worker is descheduled, and its server is woken; - wake detection: woken worker, running in the kernel, is descheduled, and if there is an idle server, it is woken to process the wake detection event; - to faciliate low scheduling latencies and cache locality, most server/worker interactions described above are performed synchronously "on CPU" via WF_CURRENT_CPU flag passed to ttwu; while at the moment the context switches are simulated by putting the switch-out task to sleep and waking the switch-into task on the same cpu, it is very much the long-term goal of this project to make the context switch much lighter, by tweaking runtime accounting and, maybe, even bypassing __schedule(); - worker blocking is detected in a hook to sched_submit_work; as mentioned above, the server is to be woken on the same CPU, synchronously; this code may not pagefault, so to access worker's and server's userspace memory (struct umcg_task), memory pages containing the worker's and the server's structs umcg_task are pinned when the worker is exiting to the userspace, and unpinned when the worker is descheduled; - worker wakeup is detected in a hook to sched_update_worker, and processed in the exit to usermode loop (via TIF_NOTIFY_RESUME); workers CAN pagefault on the wakeup path; - worker preemption is implemented by the userspace tagging the worker with UMCG_TF_PREEMPTED state flag and sending a NOOP signal to it; on the exit to usermode the worker is intercepted and its server is woken (see Documentation/userspace-api/umcg.txt for more details); - each state change is tagged with a unique timestamp (of MONOTONIC variety), so that - scheduling instrumentation is naturally available; - racing state changes are easily detected and ABA issues are avoided; see umcg_update_state() in umcg.c for implementation details, and Documentation/userspace-api/umcg.txt for a higher-level description. The previous version of the patchset can be found at https://lore.kernel.org/all/20211012232522.714898-1-posk@google.com/ containing some additional context and links to earlier discussions. More details are available in Documentation/userspace-api/umcg.txt in sibling patches, and in doc-comments in the code. Signed-off-by: Peter Oskolkov <posk@google.com>

In addition to futexes needing to do atomic operations in the userspace, a second use case is now in the works (UMCG, see https://lore.kernel.org/all/20210917180323.278250-1-posk@google.com/), so a generic facility to perform these operations has been called for (see https://lore.kernel.org/all/87ilyk9xc0.ffs@tglx/). Add a set of generic helpers to perform 32/64-bit xchg and cmpxchg operations in the userspace. Also implement the required architecture-specific support on x86_64. Signed-off-by: Peter Oskolkov <posk@google.com>

Add WF_CURRENT_CPU wake flag that advices the scheduler to move the wakee to the current CPU. This is useful for fast on-CPU context switching use cases such as UMCG. In addition, make ttwu external rather than static so that the flag could be passed to it from outside of sched/core.c. Signed-off-by: Peter Oskolkov <posk@google.com>

We've noticed cases where tasks in a cgroup are stalled on memory but there is little memory FULL pressure since tasks stay on the runqueue in reclaim. A simple example involves a single threaded program that keeps leaking and touching large amounts of memory. It runs in a cgroup with swap enabled, memory.high set at 10M and cpu.max ratio set at 5%. Though there is significant CPU pressure and memory SOME, there is barely any memory FULL since the task enters reclaim and stays on the runqueue. However, this memory-bound task is effectively stalled on memory and we expect memory FULL to match memory SOME in this scenario. The code is confused about memstall && running, thinking there is a stalled task and a productive task when there's only one task: a reclaimer that's counted as both. To fix this, we redefine the condition for PSI_MEM_FULL to check that all running tasks are in an active memstall instead of checking that there are no running tasks. case PSI_MEM_FULL: - return unlikely(tasks[NR_MEMSTALL] && !tasks[NR_RUNNING]); + return unlikely(tasks[NR_MEMSTALL] && + tasks[NR_RUNNING] == tasks[NR_MEMSTALL_RUNNING]); This will capture reclaimers. It will also capture tasks that called psi_memstall_enter() and are about to sleep, but this should be negligible noise. Signed-off-by: Brian Chen <brianchen118@gmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Link: https://lore.kernel.org/r/20211110213312.310243-1-brianchen118@gmail.com

Adds accounting for "forced idle" time, which is time where a cookie'd task forces its SMT sibling to idle, despite the presence of runnable tasks. Forced idle time is one means to measure the cost of enabling core scheduling (ie. the capacity lost due to the need to force idle). Forced idle time is attributed to the thread responsible for causing the forced idle. A few details: - Forced idle time is displayed via /proc/PID/sched. It also requires that schedstats is enabled. - Forced idle is only accounted when a sibling hyperthread is held idle despite the presence of runnable tasks. No time is charged if a sibling is idle but has no runnable tasks. - Tasks with 0 cookie are never charged forced idle. - For SMT > 2, we scale the amount of forced idle charged based on the number of forced idle siblings. Additionally, we split the time up and evenly charge it to all running tasks, as each is equally responsible for the forced idle. Signed-off-by: Josh Don <joshdon@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20211018203428.2025792-1-joshdon@google.com

Add the missing SPDX license header to include/linux/psi.h include/linux/psi_types.h kernel/sched/psi.c Signed-off-by: Liu Xinpeng <liuxp11@chinatelecom.cn> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Link: https://lore.kernel.org/r/1635133586-84611-2-git-send-email-liuxp11@chinatelecom.cn

Comment in function psi_task_switch,there are two same lines. ... * runtime state, the cgroup that contains both tasks * runtime state, the cgroup that contains both tasks ... Signed-off-by: Liu Xinpeng <liuxp11@chinatelecom.cn> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Link: https://lore.kernel.org/r/1635133586-84611-1-git-send-email-liuxp11@chinatelecom.cn

Add Kconfig support for -Wimplicit-fallthrough for both GCC and Clang. The compiler option is under configuration CC_IMPLICIT_FALLTHROUGH, which is enabled by default. Special thanks to Nathan Chancellor who fixed the Clang bug[1][2]. This bugfix only appears in Clang 14.0.0, so older versions still contain the bug and -Wimplicit-fallthrough won't be enabled for them, for now. This concludes a long journey and now we are finally getting rid of the unintentional fallthrough bug-class in the kernel, entirely. :) Link: llvm/llvm-project@9ed4a94 [1] Link: https://bugs.llvm.org/show_bug.cgi?id=51094 [2] Link: KSPP#115 Link: ClangBuiltLinux#236 Co-developed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Kees Cook <keescook@chromium.org> Co-developed-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> Reviewed-by: Nathan Chancellor <nathan@kernel.org> Tested-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

…fs-linux Pull xfs cleanups from Darrick Wong: "The most 'exciting' aspect of this branch is that the xfsprogs maintainer and I have worked through the last of the code discrepancies between kernel and userspace libxfs such that there are no code differences between the two except for #includes. IOWs, diff suffices to demonstrate that the userspace tools behave the same as the kernel, and kernel-only bits are clearly marked in the /kernel/ source code instead of just the userspace source. Summary: - Clean up open-coded swap() calls. - A little bit of #ifdef golf to complete the reunification of the kernel and userspace libxfs source code" * tag 'xfs-5.16-merge-5' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: xfs: sync xfs_btree_split macros with userspace libxfs xfs: #ifdef out perag code for userspace xfs: use swap() to make dabtree code cleaner

…ernel/git/deller/parisc-linux Pull more parisc fixes from Helge Deller: "Fix a build error in stracktrace.c, fix resolving of addresses to function names in backtraces, fix single-stepping in assembly code and flush userspace pte's when using set_pte_at()" * tag 'for-5.16/parisc-3' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux: parisc/entry: fix trace test in syscall exit path parisc: Flush kernel data mapping in set_pte_at() when installing pte for user page parisc: Fix implicit declaration of function '__kernel_text_address' parisc: Fix backtrace to always include init funtion names

Pull arch/sh updates from Rich Felker. * tag 'sh-for-5.16' of git://git.libc.org/linux-sh: sh: pgtable-3level: Fix cast to pointer from integer of different size sh: fix READ/WRITE redefinition warnings sh: define __BIG_ENDIAN for math-emu sh: math-emu: drop unused functions sh: fix kconfig unmet dependency warning for FRAME_POINTER sh: Cleanup about SPARSE_IRQ sh: kdump: add some attribute to function maple: fix wrong return value of maple_bus_init(). sh: boot: avoid unneeded rebuilds under arch/sh/boot/compressed/ sh: boot: add intermediate vmlinux.bin* to targets instead of extra-y sh: boards: Fix the cacography in irq.c sh: check return code of request_irq sh: fix trivial misannotations

Pull ARM fixes from Russell King: - Fix early_iounmap - Drop cc-option fallbacks for architecture selection * tag 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm: ARM: 9156/1: drop cc-option fallbacks for architecture selection ARM: 9155/1: fix early early_iounmap()

…cm/linux/kernel/git/robh/linux Pull devicetree fixes from Rob Herring: - Two fixes due to DT node name changes on Arm, Ltd. boards - Treewide rename of Ingenic CGU headers - Update ST email addresses - Remove Netlogic DT bindings - Dropping few more cases of redundant 'maxItems' in schemas - Convert toshiba,tc358767 bridge binding to schema * tag 'devicetree-fixes-for-5.16-1' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux: dt-bindings: watchdog: sunxi: fix error in schema bindings: media: venus: Drop redundant maxItems for power-domain-names dt-bindings: Remove Netlogic bindings clk: versatile: clk-icst: Ensure clock names are unique of: Support using 'mask' in making device bus id dt-bindings: treewide: Update @st.com email address to @foss.st.com dt-bindings: media: Update maintainers for st,stm32-hwspinlock.yaml dt-bindings: media: Update maintainers for st,stm32-cec.yaml dt-bindings: mfd: timers: Update maintainers for st,stm32-timers dt-bindings: timer: Update maintainers for st,stm32-timer dt-bindings: i2c: imx: hardware do not restrict clock-frequency to only 100 and 400 kHz dt-bindings: display: bridge: Convert toshiba,tc358767.txt to yaml dt-bindings: Rename Ingenic CGU headers to ingenic,*.h

…linux/kernel/git/tip/tip Pull timer fix from Thomas Gleixner: "A single fix for POSIX CPU timers to address a problem where POSIX CPU timer delivery stops working for a new child task because copy_process() copies state information which is only valid for the parent task" * tag 'timers-urgent-2021-11-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: posix-cpu-timers: Clear task::posix_cputimers_work in copy_process()

…ux/kernel/git/tip/tip Pull irq fixes from Thomas Gleixner: "A set of fixes for the interrupt subsystem Core code: - A regression fix for the Open Firmware interrupt mapping code where a interrupt controller property in a node caused a map property in the same node to be ignored. Interrupt chip drivers: - Workaround a limitation in SiFive PLIC interrupt chip which silently ignores an EOI when the interrupt line is masked. - Provide the missing mask/unmask implementation for the CSKY MP interrupt controller. PCI/MSI: - Prevent a use after free when PCI/MSI interrupts are released by destroying the sysfs entries before freeing the memory which is accessed in the sysfs show() function. - Implement a mask quirk for the Nvidia ION AHCI chip which does not advertise masking capability despite implementing it. Even worse the chip comes out of reset with all MSI entries masked, which due to the missing masking capability never get unmasked. - Move the check which prevents accessing the MSI[X] masking for XEN back into the low level accessors. The recent consolidation missed that these accessors can be invoked from places which do not have that check which broke XEN. Move them back to he original place instead of sprinkling tons of these checks all over the code" * tag 'irq-urgent-2021-11-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: of/irq: Don't ignore interrupt-controller when interrupt-map failed irqchip/sifive-plic: Fixup EOI failed when masked irqchip/csky-mpintc: Fixup mask/unmask implementation PCI/MSI: Destroy sysfs before freeing entries PCI: Add MSI masking quirk for Nvidia ION AHCI PCI/MSI: Deal with devices lying about their MSI mask capability PCI/MSI: Move non-mask check back into low level accessors

…/linux/kernel/git/tip/tip Pull x86 static call update from Thomas Gleixner: "A single fix for static calls to make the trampoline patching more robust by placing explicit signature bytes after the call trampoline to prevent patching random other jumps like the CFI jump table entries" * tag 'locking-urgent-2021-11-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: static_call,x86: Robustify trampoline patching

…m/linux/kernel/git/tip/tip Pull scheduler fixes from Borislav Petkov: - Avoid touching ~100 config files in order to be able to select the preemption model - clear cluster CPU masks too, on the CPU unplug path - prevent use-after-free in cfs - Prevent a race condition when updating CPU cache domains - Factor out common shared part of smp_prepare_cpus() into a common helper which can be called by both baremetal and Xen, in order to fix a booting of Xen PV guests * tag 'sched_urgent_for_v5.16_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: preempt: Restore preemption model selection configs arch_topology: Fix missing clear cluster_cpumask in remove_cpu_topology() sched/fair: Prevent dead task groups from regaining cfs_rq's sched/core: Mitigate race cpus_share_cache()/update_top_cache_domain() x86/smp: Factor out parts of native_smp_prepare_cpus()

…/linux/kernel/git/tip/tip Pull perf fixes from Borislav Petkov: - Prevent unintentional page sharing by checking whether a page reference to a PMU samples page has been acquired properly before that - Make sure the LBR_SELECT MSR is saved/restored too - Reset the LBR_SELECT MSR when resetting the LBR PMU to clear any residual data left * tag 'perf_urgent_for_v5.16_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf/core: Avoid put_page() when GUP fails perf/x86/vlbr: Add c->flags to vlbr event constraints perf/x86/lbr: Reset LBR_SELECT during vlbr reset

…linux/kernel/git/tip/tip Pull x86 fixes from Borislav Petkov: - Add the model number of a new, Raptor Lake CPU, to intel-family.h - Do not log spurious corrected MCEs on SKL too, due to an erratum - Clarify the path of paravirt ops patches upstream - Add an optimization to avoid writing out AMX components to sigframes when former are in init state * tag 'x86_urgent_for_v5.16_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/cpu: Add Raptor Lake to Intel family x86/mce: Add errata workaround for Skylake SKX37 MAINTAINERS: Add some information to PARAVIRT_OPS entry x86/fpu: Optimize out sigframe xfeatures when in init state

…ub/scm/linux/kernel/git/acme/linux Pull more perf tools updates from Arnaldo Carvalho de Melo: "Hardware tracing: - ARM: * Print the size of the buffer size consistently in hexadecimal in ARM Coresight. * Add Coresight snapshot mode support. * Update --switch-events docs in 'perf record'. * Support hardware-based PID tracing. * Track task context switch for cpu-mode events. - Vendor events: * Add metric events JSON file for power10 platform perf test: - Get 'perf test' unit tests closer to kunit. - Topology tests improvements. - Remove bashisms from some tests. perf bench: - Fix memory leak of perf_cpu_map__new() in the futex benchmarks. libbpf: - Add some more weak libbpf functions o allow building with the libbpf versions, old ones, present in distros. libbeauty: - Translate [gs]setsockopt 'level' argument integer values to strings. tools headers UAPI: - Sync futex_waitv, arch prctl, sound, i195_drm and msr-index files with the kernel sources. Documentation: - Add documentation to 'struct symbol'. - Synchronize the definition of enum perf_hw_id with code in tools/perf/design.txt" * tag 'perf-tools-for-v5.16-2021-11-13' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux: (67 commits) perf tests: Remove bash constructs from stat_all_pmu.sh perf tests: Remove bash construct from record+zstd_comp_decomp.sh perf test: Remove bash construct from stat_bpf_counters.sh test perf bench futex: Fix memory leak of perf_cpu_map__new() tools arch x86: Sync the msr-index.h copy with the kernel sources tools headers UAPI: Sync drm/i915_drm.h with the kernel sources tools headers UAPI: Sync sound/asound.h with the kernel sources tools headers UAPI: Sync linux/prctl.h with the kernel sources tools headers UAPI: Sync arch prctl headers with the kernel sources perf tools: Add more weak libbpf functions perf bpf: Avoid memory leak from perf_env__insert_btf() perf symbols: Factor out annotation init/exit perf symbols: Bit pack to save a byte perf symbols: Add documentation to 'struct symbol' tools headers UAPI: Sync files changed by new futex_waitv syscall perf test bpf: Use ARRAY_CHECK() instead of ad-hoc equivalent, addressing array_size.cocci warning perf arm-spe: Support hardware-based PID tracing perf arm-spe: Save context ID in record perf arm-spe: Update --switch-events docs in 'perf record' perf arm-spe: Track task context switch for cpu-mode events ...

…x/kernel/git/maz/arm-platforms into irq/urgent Pull irqchip fixes from Marc Zyngier: - Address an issue with the SiFive PLIC being unable to EOI a masked interrupt - Move the disable/enable methods in the CSky mpintc to mask/unmask - Fix a regression in the OF irq code where an interrupt-controller property in the same node as an interrupt-map property would get ignored Link: https://lore.kernel.org/all/20211112173459.4015233-1-maz@kernel.org

Pull zstd update from Nick Terrell: "Update to zstd-1.4.10. Add myself as the maintainer of zstd and update the zstd version in the kernel, which is now 4 years out of date, to a much more recent zstd release. This includes bug fixes, much more extensive fuzzing, and performance improvements. And generates the kernel zstd automatically from upstream zstd, so it is easier to keep the zstd verison up to date, and we don't fall so far out of date again. This includes 5 commits that update the zstd library version: - Adds a new kernel-style wrapper around zstd. This wrapper API is functionally equivalent to the subset of the current zstd API that is currently used. The wrapper API changes to be kernel style so that the symbols don't collide with zstd's symbols. The update to zstd-1.4.10 maintains the same API and preserves the semantics, so that none of the callers need to be updated. All callers are updated in the commit, because there are zero functional changes. - Adds an indirection for `lib/decompress_unzstd.c` so it doesn't depend on the layout of `lib/zstd/` to include every source file. This allows the next patch to be automatically generated. - Imports the zstd-1.4.10 source code. This commit is automatically generated from upstream zstd (https://github.com/facebook/zstd). - Adds me (terrelln@fb.com) as the maintainer of `lib/zstd`. - Fixes a newly added build warning for clang. The discussion around this patchset has been pretty long, so I've included a FAQ-style summary of the history of the patchset, and why we are taking this approach. Why do we need to update? ------------------------- The zstd version in the kernel is based off of zstd-1.3.1, which is was released August 20, 2017. Since then zstd has seen many bug fixes and performance improvements. And, importantly, upstream zstd is continuously fuzzed by OSS-Fuzz, and bug fixes aren't backported to older versions. So the only way to sanely get these fixes is to keep up to date with upstream zstd. There are no known security issues that affect the kernel, but we need to be able to update in case there are. And while there are no known security issues, there are relevant bug fixes. For example the problem with large kernel decompression has been fixed upstream for over 2 years [1] Additionally the performance improvements for kernel use cases are significant. Measured for x86_64 on my Intel i9-9900k @ 3.6 GHz: - BtrFS zstd compression at levels 1 and 3 is 5% faster - BtrFS zstd decompression+read is 15% faster - SquashFS zstd decompression+read is 15% faster - F2FS zstd compression+write at level 3 is 8% faster - F2FS zstd decompression+read is 20% faster - ZRAM decompression+read is 30% faster - Kernel zstd decompression is 35% faster - Initramfs zstd decompression+build is 5% faster On top of this, there are significant performance improvements coming down the line in the next zstd release, and the new automated update patch generation will allow us to pull them easily. How is the update patch generated? ---------------------------------- The first two patches are preparation for updating the zstd version. Then the 3rd patch in the series imports upstream zstd into the kernel. This patch is automatically generated from upstream. A script makes the necessary changes and imports it into the kernel. The changes are: - Replace all libc dependencies with kernel replacements and rewrite includes. - Remove unncessary portability macros like: #if defined(_MSC_VER). - Use the kernel xxhash instead of bundling it. This automation gets tested every commit by upstream's continuous integration. When we cut a new zstd release, we will submit a patch to the kernel to update the zstd version in the kernel. The automated process makes it easy to keep the kernel version of zstd up to date. The current zstd in the kernel shares the guts of the code, but has a lot of API and minor changes to work in the kernel. This is because at the time upstream zstd was not ready to be used in the kernel envrionment as-is. But, since then upstream zstd has evolved to support being used in the kernel as-is. Why are we updating in one big patch? ------------------------------------- The 3rd patch in the series is very large. This is because it is restructuring the code, so it both deletes the existing zstd, and re-adds the new structure. Future updates will be directly proportional to the changes in upstream zstd since the last import. They will admittidly be large, as zstd is an actively developed project, and has hundreds of commits between every release. However, there is no other great alternative. One option ruled out is to replay every upstream zstd commit. This is not feasible for several reasons: - There are over 3500 upstream commits since the zstd version in the kernel. - The automation to automatically generate the kernel update was only added recently, so older commits cannot easily be imported. - Not every upstream zstd commit builds. - Only zstd releases are "supported", and individual commits may have bugs that were fixed before a release. Another option to reduce the patch size would be to first reorganize to the new file structure, and then apply the patch. However, the current kernel zstd is formatted with clang-format to be more "kernel-like". But, the new method imports zstd as-is, without additional formatting, to allow for closer correlation with upstream, and easier debugging. So the patch wouldn't be any smaller. It also doesn't make sense to import upstream zstd commit by commit going forward. Upstream zstd doesn't support production use cases running of the development branch. We have a lot of post-commit fuzzing that catches many bugs, so indiviudal commits may be buggy, but fixed before a release. So going forward, I intend to import every (important) zstd release into the Kernel. So, while it isn't ideal, updating in one big patch is the only patch I see forward. Who is responsible for this code? --------------------------------- I am. This patchset adds me as the maintainer for zstd. Previously, there was no tree for zstd patches. Because of that, there were several patches that either got ignored, or took a long time to merge, since it wasn't clear which tree should pick them up. I'm officially stepping up as maintainer, and setting up my tree as the path through which zstd patches get merged. I'll make sure that patches to the kernel zstd get ported upstream, so they aren't erased when the next version update happens. How is this code tested? ------------------------ I tested every caller of zstd on x86_64 (BtrFS, ZRAM, SquashFS, F2FS, Kernel, InitRAMFS). I also tested Kernel & InitRAMFS on i386 and aarch64. I checked both performance and correctness. Also, thanks to many people in the community who have tested these patches locally. Lastly, this code will bake in linux-next before being merged into v5.16. Why update to zstd-1.4.10 when zstd-1.5.0 has been released? ------------------------------------------------------------ This patchset has been outstanding since 2020, and zstd-1.4.10 was the latest release when it was created. Since the update patch is automatically generated from upstream, I could generate it from zstd-1.5.0. However, there were some large stack usage regressions in zstd-1.5.0, and are only fixed in the latest development branch. And the latest development branch contains some new code that needs to bake in the fuzzer before I would feel comfortable releasing to the kernel. Once this patchset has been merged, and we've released zstd-1.5.1, we can update the kernel to zstd-1.5.1, and exercise the update process. You may notice that zstd-1.4.10 doesn't exist upstream. This release is an artifical release based off of zstd-1.4.9, with some fixes for the kernel backported from the development branch. I will tag the zstd-1.4.10 release after this patchset is merged, so the Linux Kernel is running a known version of zstd that can be debugged upstream. Why was a wrapper API added? ---------------------------- The first versions of this patchset migrated the kernel to the upstream zstd API. It first added a shim API that supported the new upstream API with the old code, then updated callers to use the new shim API, then transitioned to the new code and deleted the shim API. However, Cristoph Hellwig suggested that we transition to a kernel style API, and hide zstd's upstream API behind that. This is because zstd's upstream API is supports many other use cases, and does not follow the kernel style guide, while the kernel API is focused on the kernel's use cases, and follows the kernel style guide. Where is the previous discussion? --------------------------------- Links for the discussions of the previous versions of the patch set below. The largest changes in the design of the patchset are driven by the discussions in v11, v5, and v1. Sorry for the mix of links, I couldn't find most of the the threads on lkml.org" Link: https://lkml.org/lkml/2020/9/29/27 [1] Link: https://www.spinics.net/lists/linux-crypto/msg58189.html [v12] Link: https://lore.kernel.org/linux-btrfs/20210430013157.747152-1-nickrterrell@gmail.com/ [v11] Link: https://lore.kernel.org/lkml/20210426234621.870684-2-nickrterrell@gmail.com/ [v10] Link: https://lore.kernel.org/linux-btrfs/20210330225112.496213-1-nickrterrell@gmail.com/ [v9] Link: https://lore.kernel.org/linux-f2fs-devel/20210326191859.1542272-1-nickrterrell@gmail.com/ [v8] Link: https://lkml.org/lkml/2020/12/3/1195 [v7] Link: https://lkml.org/lkml/2020/12/2/1245 [v6] Link: https://lore.kernel.org/linux-btrfs/20200916034307.2092020-1-nickrterrell@gmail.com/ [v5] Link: https://www.spinics.net/lists/linux-btrfs/msg105783.html [v4] Link: https://lkml.org/lkml/2020/9/23/1074 [v3] Link: https://www.spinics.net/lists/linux-btrfs/msg105505.html [v2] Link: https://lore.kernel.org/linux-btrfs/20200916034307.2092020-1-nickrterrell@gmail.com/ [v1] Signed-off-by: Nick Terrell <terrelln@fb.com> Tested By: Paul Jones <paul@pauljones.id.au> Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name> Tested-by: Sedat Dilek <sedat.dilek@gmail.com> # LLVM/Clang v13.0.0 on x86-64 Tested-by: Jean-Denis Girard <jd.girard@sysnux.pf> * tag 'zstd-for-linus-v5.16' of git://github.com/terrelln/linux: lib: zstd: Add cast to silence clang's -Wbitwise-instead-of-logical MAINTAINERS: Add maintainer entry for zstd lib: zstd: Upgrade to latest upstream zstd version 1.4.10 lib: zstd: Add decompress_sources.h for decompress_unzstd lib: zstd: Add kernel-specific API

…linux Pull virtio-mem update from David Hildenbrand: "Support the VIRTIO_MEM_F_UNPLUGGED_INACCESSIBLE feature in virtio-mem, now that "accidential" access to logically unplugged memory inside added Linux memory blocks is no longer possible, because we: - Removed /dev/kmem in commit bbcd53c ("drivers/char: remove /dev/kmem for good") - Disallowed access to virtio-mem device memory via /dev/mem in commit 2128f4e ("virtio-mem: disallow mapping virtio-mem memory via /dev/mem") - Sanitized access to virtio-mem device memory via /proc/kcore in commit 0daa322 ("fs/proc/kcore: don't read offline sections, logically offline pages and hwpoisoned pages") - Sanitized access to virtio-mem device memory via /proc/vmcore in commit ce28146 ("virtio-mem: kdump mode to sanitize /proc/vmcore access") The new VIRTIO_MEM_F_UNPLUGGED_INACCESSIBLE feature that will be required by some hypervisors implementing virtio-mem in the near future, so let's support it now that we safely can" * tag 'virtio-mem-for-5.16' of git://github.com/davidhildenbrand/linux: virtio-mem: support VIRTIO_MEM_F_UNPLUGGED_INACCESSIBLE

The tests were passing but without testing and were printing the following: $ ./perf test -v 90 90: perf all PMU test : --- start --- test child forked, pid 51650 Testing cpu/branch-instructions/ ./tests/shell/stat_all_pmu.sh: 10: [: Performance counter stats for 'true': 137,307 cpu/branch-instructions/ 0.001686672 seconds time elapsed 0.001376000 seconds user 0.000000000 seconds sys: unexpected operator Changing the regexes to a grep works in sh and prints this: $ ./perf test -v 90 90: perf all PMU test : --- start --- test child forked, pid 60186 [...] Testing tlb_flush.stlb_any test child finished with 0 ---- end ---- perf all PMU test: Ok Signed-off-by: James Clark <james.clark@arm.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Florian Fainelli <f.fainelli@gmail.com> Cc: Ian Rogers <irogers@google.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: John Fastabend <john.fastabend@gmail.com> Cc: KP Singh <kpsingh@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Martin KaFai Lau <kafai@fb.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Song Liu <songliubraving@fb.com> Cc: Sumanth Korikkar <sumanthk@linux.ibm.com> Cc: Thomas Richter <tmricht@linux.ibm.com> Cc: Yonghong Song <yhs@fb.com> Cc: bpf@vger.kernel.org Cc: netdev@vger.kernel.org Link: https://lore.kernel.org/r/20211028134828.65774-4-james.clark@arm.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Commit 463538a ("perf tests: Fix test 68 zstd compression for s390") inadvertently removed the -g flag from all platforms rather than just s390, because the [[ ]] construct fails in sh. Changing to single brackets restores testing of call graphs and removes the following error from the output: $ ./perf test -v 85 85: Zstd perf.data compression/decompression : --- start --- test child forked, pid 50643 Collecting compressed record file: ./tests/shell/record+zstd_comp_decomp.sh: 15: [[: not found Fixes: 463538a ("perf tests: Fix test 68 zstd compression for s390") Signed-off-by: James Clark <james.clark@arm.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Florian Fainelli <f.fainelli@gmail.com> Cc: Ian Rogers <irogers@google.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: John Fastabend <john.fastabend@gmail.com> Cc: KP Singh <kpsingh@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Martin KaFai Lau <kafai@fb.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Song Liu <songliubraving@fb.com> Cc: Sumanth Korikkar <sumanthk@linux.ibm.com> Cc: Thomas Richter <tmricht@linux.ibm.com> Cc: Yonghong Song <yhs@fb.com> Cc: bpf@vger.kernel.org Cc: netdev@vger.kernel.org Link: https://lore.kernel.org/r/20211028134828.65774-3-james.clark@arm.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Currently the test skips with an error because == only works in bash: $ ./perf test 91 -v Couldn't bump rlimit(MEMLOCK), failures may take place when creating BPF maps, etc 91: perf stat --bpf-counters test : --- start --- test child forked, pid 44586 ./tests/shell/stat_bpf_counters.sh: 26: [: -v: unexpected operator test child finished with -2 ---- end ---- perf stat --bpf-counters test: Skip Changing == to = does the same thing, but doesn't result in an error: ./perf test 91 -v Couldn't bump rlimit(MEMLOCK), failures may take place when creating BPF maps, etc 91: perf stat --bpf-counters test : --- start --- test child forked, pid 45833 Skipping: --bpf-counters not supported Error: unknown option `bpf-counters' [...] test child finished with -2 ---- end ---- perf stat --bpf-counters test: Skip Signed-off-by: James Clark <james.clark@arm.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Florian Fainelli <f.fainelli@gmail.com> Cc: Ian Rogers <irogers@google.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: John Fastabend <john.fastabend@gmail.com> Cc: KP Singh <kpsingh@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Martin KaFai Lau <kafai@fb.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Song Liu <songliubraving@fb.com> Cc: Sumanth Korikkar <sumanthk@linux.ibm.com> Cc: Thomas Richter <tmricht@linux.ibm.com> Cc: Yonghong Song <yhs@fb.com> Cc: bpf@vger.kernel.org Cc: netdev@vger.kernel.org Link: https://lore.kernel.org/r/20211028134828.65774-2-james.clark@arm.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

ASan reports memory leaks while running: $ sudo ./perf bench futex all The leaks are caused by perf_cpu_map__new not being freed. This patch adds the missing perf_cpu_map__put since it calls cpu_map_delete implicitly. Fixes: 9c3516d ("libperf: Add perf_cpu_map__new()/perf_cpu_map__read() functions") Signed-off-by: Sohaib Mohamed <sohaib.amhmd@gmail.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: André Almeida <andrealmeid@collabora.com> Cc: Darren Hart <dvhart@infradead.org> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Ian Rogers <irogers@google.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sohaib Mohamed <sohaib.amhmd@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lore.kernel.org/lkml/20211112201134.77892-1-sohaib.amhmd@gmail.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

To pick up the changes in: dae1bd5 ("x86/msr-index: Add MSRs for XFD") Addressing these tools/perf build warnings: diff -u tools/arch/x86/include/asm/msr-index.h arch/x86/include/asm/msr-index.h Warning: Kernel ABI header at 'tools/arch/x86/include/asm/msr-index.h' differs from latest version at 'arch/x86/include/asm/msr-index.h' That makes the beautification scripts to pick some new entries: $ diff -u tools/arch/x86/include/asm/msr-index.h arch/x86/include/asm/msr-index.h --- tools/arch/x86/include/asm/msr-index.h 2021-07-15 16:17:01.819817827 -0300 +++ arch/x86/include/asm/msr-index.h 2021-11-06 15:49:33.738517311 -0300 @@ -625,6 +625,8 @@ #define MSR_IA32_BNDCFGS_RSVD 0x00000ffc +#define MSR_IA32_XFD 0x000001c4 +#define MSR_IA32_XFD_ERR 0x000001c5 #define MSR_IA32_XSS 0x00000da0 #define MSR_IA32_APICBASE 0x0000001b $ tools/perf/trace/beauty/tracepoints/x86_msr.sh > /tmp/before $ cp arch/x86/include/asm/msr-index.h tools/arch/x86/include/asm/msr-index.h $ tools/perf/trace/beauty/tracepoints/x86_msr.sh > /tmp/after $ diff -u /tmp/before /tmp/after --- /tmp/before 2021-11-13 11:10:39.964201505 -0300 +++ /tmp/after 2021-11-13 11:10:47.902410873 -0300 @@ -93,6 +93,8 @@ [0x000001b0] = "IA32_ENERGY_PERF_BIAS", [0x000001b1] = "IA32_PACKAGE_THERM_STATUS", [0x000001b2] = "IA32_PACKAGE_THERM_INTERRUPT", + [0x000001c4] = "IA32_XFD", + [0x000001c5] = "IA32_XFD_ERR", [0x000001c8] = "LBR_SELECT", [0x000001c9] = "LBR_TOS", [0x000001d9] = "IA32_DEBUGCTLMSR", $ And this gets rebuilt: CC /tmp/build/perf/trace/beauty/tracepoints/x86_msr.o INSTALL trace_plugins LD /tmp/build/perf/trace/beauty/tracepoints/perf-in.o LD /tmp/build/perf/trace/beauty/perf-in.o LD /tmp/build/perf/perf-in.o LINK /tmp/build/perf/perf Now one can trace systemwide asking to see backtraces to where those MSRs are being read/written with: # perf trace -e msr:*_msr/max-stack=32/ --filter="msr==IA32_XFD || msr==IA32_XFD_ERR" ^C# # If we use -v (verbose mode) we can see what it does behind the scenes: # perf trace -v -e msr:*_msr/max-stack=32/ --filter="msr==IA32_XFD || msr==IA32_XFD_ERR" <SNIP> New filter for msr:read_msr: (msr==0x1c4 || msr==0x1c5) && (common_pid != 4448951 && common_pid != 8781) New filter for msr:write_msr: (msr==0x1c4 || msr==0x1c5) && (common_pid != 4448951 && common_pid != 8781) <SNIP> ^C# Example with a frequent msr: # perf trace -v -e msr:*_msr/max-stack=32/ --filter="msr==IA32_SPEC_CTRL" --max-events 2 Using CPUID AuthenticAMD-25-21-0 0x48 New filter for msr:read_msr: (msr==0x48) && (common_pid != 3738351 && common_pid != 3564) 0x48 New filter for msr:write_msr: (msr==0x48) && (common_pid != 3738351 && common_pid != 3564) mmap size 528384B Looking at the vmlinux_path (8 entries long) symsrc__init: build id mismatch for vmlinux. Using /proc/kcore for kernel data Using /proc/kallsyms for symbols 0.000 pipewire/2479 msr:write_msr(msr: IA32_SPEC_CTRL, val: 6) do_trace_write_msr ([kernel.kallsyms]) do_trace_write_msr ([kernel.kallsyms]) __switch_to_xtra ([kernel.kallsyms]) __switch_to ([kernel.kallsyms]) __schedule ([kernel.kallsyms]) schedule ([kernel.kallsyms]) schedule_hrtimeout_range_clock ([kernel.kallsyms]) do_epoll_wait ([kernel.kallsyms]) __x64_sys_epoll_wait ([kernel.kallsyms]) do_syscall_64 ([kernel.kallsyms]) entry_SYSCALL_64_after_hwframe ([kernel.kallsyms]) epoll_wait (/usr/lib64/libc-2.33.so) [0x76c4] (/usr/lib64/spa-0.2/support/libspa-support.so) [0x4cf0] (/usr/lib64/spa-0.2/support/libspa-support.so) 0.027 :0/0 msr:write_msr(msr: IA32_SPEC_CTRL, val: 2) do_trace_write_msr ([kernel.kallsyms]) do_trace_write_msr ([kernel.kallsyms]) __switch_to_xtra ([kernel.kallsyms]) __switch_to ([kernel.kallsyms]) __schedule ([kernel.kallsyms]) schedule_idle ([kernel.kallsyms]) do_idle ([kernel.kallsyms]) cpu_startup_entry ([kernel.kallsyms]) start_kernel ([kernel.kallsyms]) secondary_startup_64_no_verify ([kernel.kallsyms]) # Cc: Borislav Petkov <bp@suse.de> Cc: Chang S. Bae <chang.seok.bae@intel.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Link: https://lore.kernel.org/lkml/YY%2FJdb6on7swsn+C@kernel.org/ Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

To pick up the changes in: e5e3217 ("drm/i915/guc: Connect UAPI to GuC multi-lrc interface") 9409eb3 ("drm/i915: Expose logical engine instance to user") ea673f1 ("drm/i915/uapi: Add comment clarifying purpose of I915_TILING_* values") d3ac8d4 ("drm/i915/pxp: interfaces for using protected objects") cbbd376 ("drm/i915/pxp: Create the arbitrary session after boot") That don't add any new ioctl, so no changes in tooling. This silences this perf build warning: Warning: Kernel ABI header at 'tools/include/uapi/drm/i915_drm.h' differs from latest version at 'include/uapi/drm/i915_drm.h' diff -u tools/include/uapi/drm/i915_drm.h include/uapi/drm/i915_drm.h Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com> Cc: Huang, Sean Z <sean.z.huang@intel.com> Cc: John Harrison <John.C.Harrison@Intel.com> Cc: Matthew Brost <matthew.brost@intel.com> Cc: Matt Roper <matthew.d.roper@intel.com> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

To pick up the changes in: 5aec579 ("ALSA: uapi: Fix a C++ style comment in asound.h") That is just changing a // style comment to /* */. This silences this perf build warning: Warning: Kernel ABI header at 'tools/include/uapi/sound/asound.h' differs from latest version at 'include/uapi/sound/asound.h' diff -u tools/include/uapi/sound/asound.h include/uapi/sound/asound.h Cc: Takashi Iwai <tiwai@suse.de> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

To pick the changes in: 61bc346 ("uapi/linux/prctl: provide macro definitions for the PR_SCHED_CORE type argument") That don't result in any changes in tooling: $ tools/perf/trace/beauty/prctl_option.sh > before $ cp include/uapi/linux/prctl.h tools/include/uapi/linux/prctl.h $ tools/perf/trace/beauty/prctl_option.sh > after $ diff -u before after $ Just silences this perf tools build warning: Warning: Kernel ABI header at 'tools/include/uapi/linux/prctl.h' differs from latest version at 'include/uapi/linux/prctl.h' diff -u tools/include/uapi/linux/prctl.h include/uapi/linux/prctl.h Cc: Christian Brauner <christian.brauner@ubuntu.com> Cc: Eugene Syromiatnikov <esyr@redhat.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Commits on Nov 21, 2021

Commits on Nov 17, 2021

Commits on Nov 14, 2021

Commits on Nov 13, 2021