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* Merge tag 'perf-core-2021-02-17' of ↵Linus Torvalds2021-02-212-6/+52
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull performance event updates from Ingo Molnar: - Add CPU-PMU support for Intel Sapphire Rapids CPUs - Extend the perf ABI with PERF_SAMPLE_WEIGHT_STRUCT, to offer two-parameter sampling event feedback. Not used yet, but is intended for Golden Cove CPU-PMU, which can provide both the instruction latency and the cache latency information for memory profiling events. - Remove experimental, default-disabled perfmon-v4 counter_freezing support that could only be enabled via a boot option. The hardware is hopelessly broken, we'd like to make sure nobody starts relying on this, as it would only end in tears. - Fix energy/power events on Intel SPR platforms - Simplify the uprobes resume_execution() logic - Misc smaller fixes. * tag 'perf-core-2021-02-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf/x86/rapl: Fix psys-energy event on Intel SPR platform perf/x86/rapl: Only check lower 32bits for RAPL energy counters perf/x86/rapl: Add msr mask support perf/x86/kvm: Add Cascade Lake Xeon steppings to isolation_ucodes[] perf/x86/intel: Support CPUID 10.ECX to disable fixed counters perf/x86/intel: Add perf core PMU support for Sapphire Rapids perf/x86/intel: Filter unsupported Topdown metrics event perf/x86/intel: Factor out intel_update_topdown_event() perf/core: Add PERF_SAMPLE_WEIGHT_STRUCT perf/intel: Remove Perfmon-v4 counter_freezing support x86/perf: Use static_call for x86_pmu.guest_get_msrs perf/x86/intel/uncore: With > 8 nodes, get pci bus die id from NUMA info perf/x86/intel/uncore: Store the logical die id instead of the physical die id. x86/kprobes: Do not decode opcode in resume_execution()
| * perf/x86/intel: Add perf core PMU support for Sapphire RapidsKan Liang2021-02-011-2/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add perf core PMU support for the Intel Sapphire Rapids server, which is the successor of the Intel Ice Lake server. The enabling code is based on Ice Lake, but there are several new features introduced. The event encoding is changed and simplified, e.g., the event codes which are below 0x90 are restricted to counters 0-3. The event codes which above 0x90 are likely to have no restrictions. The event constraints, extra_regs(), and hardware cache events table are changed accordingly. A new Precise Distribution (PDist) facility is introduced, which further minimizes the skid when a precise event is programmed on the GP counter 0. Enable the Precise Distribution (PDist) facility with :ppp event. For this facility to work, the period must be initialized with a value larger than 127. Add spr_limit_period() to apply the limit for :ppp event. Two new data source fields, data block & address block, are added in the PEBS Memory Info Record for the load latency event. To enable the feature, - An auxiliary event has to be enabled together with the load latency event on Sapphire Rapids. A new flag PMU_FL_MEM_LOADS_AUX is introduced to indicate the case. A new event, mem-loads-aux, is exposed to sysfs for the user tool. Add a check in hw_config(). If the auxiliary event is not detected, return an unique error -ENODATA. - The union perf_mem_data_src is extended to support the new fields. - Ice Lake and earlier models do not support block information, but the fields may be set by HW on some machines. Add pebs_no_block to explicitly indicate the previous platforms which don't support the new block fields. Accessing the new block fields are ignored on those platforms. A new store Latency facility is introduced, which leverages the PEBS facility where it can provide additional information about sampled stores. The additional information includes the data address, memory auxiliary info (e.g. Data Source, STLB miss) and the latency of the store access. To enable the facility, the new event (0x02cd) has to be programed on the GP counter 0. A new flag PERF_X86_EVENT_PEBS_STLAT is introduced to indicate the event. The store_latency_data() is introduced to parse the memory auxiliary info. The layout of access latency field of PEBS Memory Info Record has been changed. Two latency, instruction latency (bit 15:0) and cache access latency (bit 47:32) are recorded. - The cache access latency is similar to previous memory access latency. For loads, the latency starts by the actual cache access until the data is returned by the memory subsystem. For stores, the latency starts when the demand write accesses the L1 data cache and lasts until the cacheline write is completed in the memory subsystem. The cache access latency is stored in low 32bits of the sample type PERF_SAMPLE_WEIGHT_STRUCT. - The instruction latency starts by the dispatch of the load operation for execution and lasts until completion of the instruction it belongs to. Add a new flag PMU_FL_INSTR_LATENCY to indicate the instruction latency support. The instruction latency is stored in the bit 47:32 of the sample type PERF_SAMPLE_WEIGHT_STRUCT. Extends the PERF_METRICS MSR to feature TMA method level 2 metrics. The lower half of the register is the TMA level 1 metrics (legacy). The upper half is also divided into four 8-bit fields for the new level 2 metrics. Expose all eight Topdown metrics events to user space. The full description for the SPR features can be found at Intel Architecture Instruction Set Extensions and Future Features Programming Reference, 319433-041. Signed-off-by: Kan Liang <kan.liang@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/1611873611-156687-5-git-send-email-kan.liang@linux.intel.com
| * perf/core: Add PERF_SAMPLE_WEIGHT_STRUCTKan Liang2021-02-012-4/+42
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Current PERF_SAMPLE_WEIGHT sample type is very useful to expresses the cost of an action represented by the sample. This allows the profiler to scale the samples to be more informative to the programmer. It could also help to locate a hotspot, e.g., when profiling by memory latencies, the expensive load appear higher up in the histograms. But current PERF_SAMPLE_WEIGHT sample type is solely determined by one factor. This could be a problem, if users want two or more factors to contribute to the weight. For example, Golden Cove core PMU can provide both the instruction latency and the cache Latency information as factors for the memory profiling. For current X86 platforms, although meminfo::latency is defined as a u64, only the lower 32 bits include the valid data in practice (No memory access could last than 4G cycles). The higher 32 bits can be used to store new factors. Add a new sample type, PERF_SAMPLE_WEIGHT_STRUCT, to indicate the new sample weight structure. It shares the same space as the PERF_SAMPLE_WEIGHT sample type. Users can apply either the PERF_SAMPLE_WEIGHT sample type or the PERF_SAMPLE_WEIGHT_STRUCT sample type to retrieve the sample weight, but they cannot apply both sample types simultaneously. Currently, only X86 and PowerPC use the PERF_SAMPLE_WEIGHT sample type. - For PowerPC, there is nothing changed for the PERF_SAMPLE_WEIGHT sample type. There is no effect for the new PERF_SAMPLE_WEIGHT_STRUCT sample type. PowerPC can re-struct the weight field similarly later. - For X86, the same value will be dumped for the PERF_SAMPLE_WEIGHT sample type or the PERF_SAMPLE_WEIGHT_STRUCT sample type for now. The following patches will apply the new factors for the PERF_SAMPLE_WEIGHT_STRUCT sample type. The field in the union perf_sample_weight should be shared among different architectures. A generic name is required, but it's hard to abstract a name that applies to all architectures. For example, on X86, the fields are to store all kinds of latency. While on PowerPC, it stores MMCRA[TECX/TECM], which should not be latency. So a general name prefix 'var$NUM' is used here. Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Kan Liang <kan.liang@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/1611873611-156687-2-git-send-email-kan.liang@linux.intel.com
* | Merge tag 'sched-core-2021-02-17' of ↵Linus Torvalds2021-02-2112-62/+376
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler updates from Ingo Molnar: "Core scheduler updates: - Add CONFIG_PREEMPT_DYNAMIC: this in its current form adds the preempt=none/voluntary/full boot options (default: full), to allow distros to build a PREEMPT kernel but fall back to close to PREEMPT_VOLUNTARY (or PREEMPT_NONE) runtime scheduling behavior via a boot time selection. There's also the /debug/sched_debug switch to do this runtime. This feature is implemented via runtime patching (a new variant of static calls). The scope of the runtime patching can be best reviewed by looking at the sched_dynamic_update() function in kernel/sched/core.c. ( Note that the dynamic none/voluntary mode isn't 100% identical, for example preempt-RCU is available in all cases, plus the preempt count is maintained in all models, which has runtime overhead even with the code patching. ) The PREEMPT_VOLUNTARY/PREEMPT_NONE models, used by the vast majority of distributions, are supposed to be unaffected. - Fix ignored rescheduling after rcu_eqs_enter(). This is a bug that was found via rcutorture triggering a hang. The bug is that rcu_idle_enter() may wake up a NOCB kthread, but this happens after the last generic need_resched() check. Some cpuidle drivers fix it by chance but many others don't. In true 2020 fashion the original bug fix has grown into a 5-patch scheduler/RCU fix series plus another 16 RCU patches to address the underlying issue of missed preemption events. These are the initial fixes that should fix current incarnations of the bug. - Clean up rbtree usage in the scheduler, by providing & using the following consistent set of rbtree APIs: partial-order; less() based: - rb_add(): add a new entry to the rbtree - rb_add_cached(): like rb_add(), but for a rb_root_cached total-order; cmp() based: - rb_find(): find an entry in an rbtree - rb_find_add(): find an entry, and add if not found - rb_find_first(): find the first (leftmost) matching entry - rb_next_match(): continue from rb_find_first() - rb_for_each(): iterate a sub-tree using the previous two - Improve the SMP/NUMA load-balancer: scan for an idle sibling in a single pass. This is a 4-commit series where each commit improves one aspect of the idle sibling scan logic. - Improve the cpufreq cooling driver by getting the effective CPU utilization metrics from the scheduler - Improve the fair scheduler's active load-balancing logic by reducing the number of active LB attempts & lengthen the load-balancing interval. This improves stress-ng mmapfork performance. - Fix CFS's estimated utilization (util_est) calculation bug that can result in too high utilization values Misc updates & fixes: - Fix the HRTICK reprogramming & optimization feature - Fix SCHED_SOFTIRQ raising race & warning in the CPU offlining code - Reduce dl_add_task_root_domain() overhead - Fix uprobes refcount bug - Process pending softirqs in flush_smp_call_function_from_idle() - Clean up task priority related defines, remove *USER_*PRIO and USER_PRIO() - Simplify the sched_init_numa() deduplication sort - Documentation updates - Fix EAS bug in update_misfit_status(), which degraded the quality of energy-balancing - Smaller cleanups" * tag 'sched-core-2021-02-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (51 commits) sched,x86: Allow !PREEMPT_DYNAMIC entry/kvm: Explicitly flush pending rcuog wakeup before last rescheduling point entry: Explicitly flush pending rcuog wakeup before last rescheduling point rcu/nocb: Trigger self-IPI on late deferred wake up before user resume rcu/nocb: Perform deferred wake up before last idle's need_resched() check rcu: Pull deferred rcuog wake up to rcu_eqs_enter() callers sched/features: Distinguish between NORMAL and DEADLINE hrtick sched/features: Fix hrtick reprogramming sched/deadline: Reduce rq lock contention in dl_add_task_root_domain() uprobes: (Re)add missing get_uprobe() in __find_uprobe() smp: Process pending softirqs in flush_smp_call_function_from_idle() sched: Harden PREEMPT_DYNAMIC static_call: Allow module use without exposing static_call_key sched: Add /debug/sched_preempt preempt/dynamic: Support dynamic preempt with preempt= boot option preempt/dynamic: Provide irqentry_exit_cond_resched() static call preempt/dynamic: Provide preempt_schedule[_notrace]() static calls preempt/dynamic: Provide cond_resched() and might_resched() static calls preempt: Introduce CONFIG_PREEMPT_DYNAMIC static_call: Provide DEFINE_STATIC_CALL_RET0() ...
| * | entry/kvm: Explicitly flush pending rcuog wakeup before last rescheduling pointFrederic Weisbecker2021-02-171-0/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Following the idle loop model, cleanly check for pending rcuog wakeup before the last rescheduling point upon resuming to guest mode. This way we can avoid to do it from rcu_user_enter() with the last resort self-IPI hack that enforces rescheduling. Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20210131230548.32970-6-frederic@kernel.org
| * | rcu/nocb: Perform deferred wake up before last idle's need_resched() checkFrederic Weisbecker2021-02-171-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Entering RCU idle mode may cause a deferred wake up of an RCU NOCB_GP kthread (rcuog) to be serviced. Usually a local wake up happening while running the idle task is handled in one of the need_resched() checks carefully placed within the idle loop that can break to the scheduler. Unfortunately the call to rcu_idle_enter() is already beyond the last generic need_resched() check and we may halt the CPU with a resched request unhandled, leaving the task hanging. Fix this with splitting the rcuog wakeup handling from rcu_idle_enter() and place it before the last generic need_resched() check in the idle loop. It is then assumed that no call to call_rcu() will be performed after that in the idle loop until the CPU is put in low power mode. Fixes: 96d3fd0d315a (rcu: Break call_rcu() deadlock involving scheduler and perf) Reported-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20210131230548.32970-3-frederic@kernel.org
| * | sched: Harden PREEMPT_DYNAMICPeter Zijlstra2021-02-172-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Use the new EXPORT_STATIC_CALL_TRAMP() / static_call_mod() to unexport the static_call_key for the PREEMPT_DYNAMIC calls such that modules can no longer update these calls. Having modules change/hi-jack the preemption calls would be horrible. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | static_call: Allow module use without exposing static_call_keyJosh Poimboeuf2021-02-173-5/+49
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When exporting static_call_key; with EXPORT_STATIC_CALL*(), the module can use static_call_update() to change the function called. This is not desirable in general. Not exporting static_call_key however also disallows usage of static_call(), since objtool needs the key to construct the static_call_site. Solve this by allowing objtool to create the static_call_site using the trampoline address when it builds a module and cannot find the static_call_key symbol. The module loader will then try and map the trampole back to a key before it constructs the normal sites list. Doing this requires a trampoline -> key associsation, so add another magic section that keeps those. Originally-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lkml.kernel.org/r/20210127231837.ifddpn7rhwdaepiu@treble
| * | preempt/dynamic: Provide irqentry_exit_cond_resched() static callPeter Zijlstra (Intel)2021-02-171-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Provide static call to control IRQ preemption (called in CONFIG_PREEMPT) so that we can override its behaviour when preempt= is overriden. Since the default behaviour is full preemption, its call is initialized to provide IRQ preemption when preempt= isn't passed. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lkml.kernel.org/r/20210118141223.123667-8-frederic@kernel.org
| * | preempt/dynamic: Provide cond_resched() and might_resched() static callsPeter Zijlstra (Intel)2021-02-172-7/+43
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Provide static calls to control cond_resched() (called in !CONFIG_PREEMPT) and might_resched() (called in CONFIG_PREEMPT_VOLUNTARY) to that we can override their behaviour when preempt= is overriden. Since the default behaviour is full preemption, both their calls are ignored when preempt= isn't passed. [fweisbec: branch might_resched() directly to __cond_resched(), only define static calls when PREEMPT_DYNAMIC] Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lkml.kernel.org/r/20210118141223.123667-6-frederic@kernel.org
| * | static_call: Provide DEFINE_STATIC_CALL_RET0()Frederic Weisbecker2021-02-171-8/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | DECLARE_STATIC_CALL() must pass the original function targeted for a given static call. But DEFINE_STATIC_CALL() may want to initialize it as off. In this case we can't pass NULL (for functions without return value) or __static_call_return0 (for functions returning a value) directly to DEFINE_STATIC_CALL() as that may trigger a static call redeclaration with a different function prototype. Type casts neither can work around that as they don't get along with typeof(). The proper way to do that for functions that don't return a value is to use DEFINE_STATIC_CALL_NULL(). But functions returning a actual value don't have an equivalent yet. Provide DEFINE_STATIC_CALL_RET0() to solve this situation. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lkml.kernel.org/r/20210118141223.123667-3-frederic@kernel.org
| * | static_call/x86: Add __static_call_return0()Peter Zijlstra2021-02-171-0/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Provide a stub function that return 0 and wire up the static call site patching to replace the CALL with a single 5 byte instruction that clears %RAX, the return value register. The function can be cast to any function pointer type that has a single %RAX return (including pointers). Also provide a version that returns an int for convenience. We are clearing the entire %RAX register in any case, whether the return value is 32 or 64 bits, since %RAX is always a scratch register anyway. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lkml.kernel.org/r/20210118141223.123667-2-frederic@kernel.org
| * | static_call: Pull some static_call declarations to the type headersPeter Zijlstra2021-02-172-21/+27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Some static call declarations are going to be needed on low level header files. Move the necessary material to the dedicated static call types header to avoid inclusion dependency hell. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lkml.kernel.org/r/20210118141223.123667-4-frederic@kernel.org
| * | sched: Remove USER_PRIO, TASK_USER_PRIO and MAX_USER_PRIODietmar Eggemann2021-02-171-9/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The only remaining use of MAX_USER_PRIO (and USER_PRIO) is the SCALE_PRIO() definition in the PowerPC Cell architecture's Synergistic Processor Unit (SPU) scheduler. TASK_USER_PRIO isn't used anymore. Commit fe443ef2ac42 ("[POWERPC] spusched: Dynamic timeslicing for SCHED_OTHER") copied SCALE_PRIO() from the task scheduler in v2.6.23. Commit a4ec24b48dde ("sched: tidy up SCHED_RR") removed it from the task scheduler in v2.6.24. Commit 3ee237dddcd8 ("sched/prio: Add 3 macros of MAX_NICE, MIN_NICE and NICE_WIDTH in prio.h") introduced NICE_WIDTH much later. With: MAX_USER_PRIO = USER_PRIO(MAX_PRIO) = MAX_PRIO - MAX_RT_PRIO MAX_PRIO = MAX_RT_PRIO + NICE_WIDTH MAX_USER_PRIO = MAX_RT_PRIO + NICE_WIDTH - MAX_RT_PRIO MAX_USER_PRIO = NICE_WIDTH MAX_USER_PRIO can be replaced by NICE_WIDTH to be able to remove all the {*_}USER_PRIO defines. Signed-off-by: Dietmar Eggemann <dietmar.eggemann@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lkml.kernel.org/r/20210128131040.296856-3-dietmar.eggemann@arm.com
| * | sched: Remove MAX_USER_RT_PRIODietmar Eggemann2021-02-171-8/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit d46523ea32a7 ("[PATCH] fix MAX_USER_RT_PRIO and MAX_RT_PRIO") was introduced due to a a small time period in which the realtime patch set was using different values for MAX_USER_RT_PRIO and MAX_RT_PRIO. This is no longer true, i.e. now MAX_RT_PRIO == MAX_USER_RT_PRIO. Get rid of MAX_USER_RT_PRIO and make everything use MAX_RT_PRIO instead. Signed-off-by: Dietmar Eggemann <dietmar.eggemann@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lkml.kernel.org/r/20210128131040.296856-2-dietmar.eggemann@arm.com
| * | rbtree, perf: Use new rbtree helpersPeter Zijlstra2021-02-171-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Reduce rbtree boiler plate by using the new helpers. One noteworthy change is unification of the various (partial) compare functions. We construct a subtree match by forcing the sub-order to always match, see __group_cmp(). Due to 'const' we had to touch cgroup_id(). Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Tejun Heo <tj@kernel.org> Acked-by: Davidlohr Bueso <dbueso@suse.de>
| * | rbtree, sched/deadline: Use rb_add_cached()Peter Zijlstra2021-02-171-4/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Reduce rbtree boiler plate by using the new helpers. Make rb_add_cached() / rb_erase_cached() return a pointer to the leftmost node to aid in updating additional state. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Davidlohr Bueso <dbueso@suse.de>
| * | rbtree: Add generic add and find helpersPeter Zijlstra2021-02-171-0/+190
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | I've always been bothered by the endless (fragile) boilerplate for rbtree, and I recently wrote some rbtree helpers for objtool and figured I should lift them into the kernel and use them more widely. Provide: partial-order; less() based: - rb_add(): add a new entry to the rbtree - rb_add_cached(): like rb_add(), but for a rb_root_cached total-order; cmp() based: - rb_find(): find an entry in an rbtree - rb_find_add(): find an entry, and add if not found - rb_find_first(): find the first (leftmost) matching entry - rb_next_match(): continue from rb_find_first() - rb_for_each(): iterate a sub-tree using the previous two Inlining and constant propagation should see the compiler inline the whole thing, including the various compare functions. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Michel Lespinasse <walken@google.com> Acked-by: Davidlohr Bueso <dbueso@suse.de>
| * | Merge tag 'v5.11' into sched/core, to pick up fixes & refresh the branchIngo Molnar2021-02-1779-449/+427
| |\ \ | | | | | | | | | | | | Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | sched: Correctly sort struct predeclarationsPeter Oskolkov2021-01-271-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The comment says: /* task_struct member predeclarations (sorted alphabetically): */ So move io_uring_task where it belongs (alphabetically). Signed-off-by: Peter Oskolkov <posk@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20210126193449.487547-1-posk@google.com
| * | | sched/topology: Make sched_init_numa() use a set for the deduplicating sortValentin Schneider2021-01-271-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The deduplicating sort in sched_init_numa() assumes that the first line in the distance table contains all unique values in the entire table. I've been trying to pen what this exactly means for the topology, but it's not straightforward. For instance, topology.c uses this example: node 0 1 2 3 0: 10 20 20 30 1: 20 10 20 20 2: 20 20 10 20 3: 30 20 20 10 0 ----- 1 | / | | / | | / | 2 ----- 3 Which works out just fine. However, if we swap nodes 0 and 1: 1 ----- 0 | / | | / | | / | 2 ----- 3 we get this distance table: node 0 1 2 3 0: 10 20 20 20 1: 20 10 20 30 2: 20 20 10 20 3: 20 30 20 10 Which breaks the deduplicating sort (non-representative first line). In this case this would just be a renumbering exercise, but it so happens that we can have a deduplicating sort that goes through the whole table in O(n²) at the extra cost of a temporary memory allocation (i.e. any form of set). The ACPI spec (SLIT) mentions distances are encoded on 8 bits. Following this, implement the set as a 256-bits bitmap. Should this not be satisfactory (i.e. we want to support 32-bit values), then we'll have to go for some other sparse set implementation. This has the added benefit of letting us allocate just the right amount of memory for sched_domains_numa_distance[], rather than an arbitrary (nr_node_ids + 1). Note: DT binding equivalent (distance-map) decodes distances as 32-bit values. Signed-off-by: Valentin Schneider <valentin.schneider@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20210122123943.1217-2-valentin.schneider@arm.com
| * | | sched/core: Rename schedutil_cpu_util() and allow rest of the kernel to use itViresh Kumar2021-01-141-0/+5
| | |/ | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There is nothing schedutil specific in schedutil_cpu_util(), rename it to effective_cpu_util(). Also create and expose another wrapper sched_cpu_util() which can be used by other parts of the kernel, like thermal core (that will be done in a later commit). Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Link: https://lkml.kernel.org/r/db011961fb3bb8bef1c0eda5cd64564637d3ef31.1607400596.git.viresh.kumar@linaro.org
* | | Merge tag 'core-mm-2021-02-17' of ↵Linus Torvalds2021-02-212-6/+7
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull tlb gather updates from Ingo Molnar: "Theses fix MM (soft-)dirty bit management in the procfs code & clean up the TLB gather API" * tag 'core-mm-2021-02-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/ldt: Use tlb_gather_mmu_fullmm() when freeing LDT page-tables tlb: arch: Remove empty __tlb_remove_tlb_entry() stubs tlb: mmu_gather: Remove start/end arguments from tlb_gather_mmu() tlb: mmu_gather: Introduce tlb_gather_mmu_fullmm() tlb: mmu_gather: Remove unused start/end arguments from tlb_finish_mmu() mm: proc: Invalidate TLB after clearing soft-dirty page state
| * | | tlb: mmu_gather: Remove start/end arguments from tlb_gather_mmu()Will Deacon2021-01-291-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The 'start' and 'end' arguments to tlb_gather_mmu() are no longer needed now that there is a separate function for 'fullmm' flushing. Remove the unused arguments and update all callers. Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Will Deacon <will@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Yu Zhao <yuzhao@google.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/r/CAHk-=wjQWa14_4UpfDf=fiineNP+RH74kZeDMo_f1D35xNzq9w@mail.gmail.com
| * | | tlb: mmu_gather: Introduce tlb_gather_mmu_fullmm()Will Deacon2021-01-292-2/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Passing the range '0, -1' to tlb_gather_mmu() sets the 'fullmm' flag, which indicates that the mm_struct being operated on is going away. In this case, some architectures (such as arm64) can elide TLB invalidation by ensuring that the TLB tag (ASID) associated with this mm is not immediately reclaimed. Although this behaviour is documented in asm-generic/tlb.h, it's subtle and easily missed. Introduce tlb_gather_mmu_fullmm() to make it clearer that this is for the entire mm and WARN() if tlb_gather_mmu() is called with the 'fullmm' address range. Signed-off-by: Will Deacon <will@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Yu Zhao <yuzhao@google.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lkml.kernel.org/r/20210127235347.1402-4-will@kernel.org
| * | | tlb: mmu_gather: Remove unused start/end arguments from tlb_finish_mmu()Will Deacon2021-01-291-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since commit 7a30df49f63a ("mm: mmu_gather: remove __tlb_reset_range() for force flush"), the 'start' and 'end' arguments to tlb_finish_mmu() are no longer used, since we flush the whole mm in case of a nested invalidation. Remove the unused arguments and update all callers. Signed-off-by: Will Deacon <will@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Yu Zhao <yuzhao@google.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lkml.kernel.org/r/20210127235347.1402-3-will@kernel.org
* | | | Merge tag 'locking-core-2021-02-17' of ↵Linus Torvalds2021-02-218-43/+54
|\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull locking updates from Ingo Molnar: "Core locking primitives updates: - Remove mutex_trylock_recursive() from the API - no users left - Simplify + constify the futex code a bit Lockdep updates: - Teach lockdep about local_lock_t - Add CONFIG_DEBUG_IRQFLAGS=y debug config option to check for potentially unsafe IRQ mask restoration patterns. (I.e. calling raw_local_irq_restore() with IRQs enabled.) - Add wait context self-tests - Fix graph lock corner case corrupting internal data structures - Fix noinstr annotations LKMM updates: - Simplify the litmus tests - Documentation fixes KCSAN updates: - Re-enable KCSAN instrumentation in lib/random32.c Misc fixes: - Don't branch-trace static label APIs - DocBook fix - Remove stale leftover empty file" * tag 'locking-core-2021-02-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (24 commits) checkpatch: Don't check for mutex_trylock_recursive() locking/mutex: Kill mutex_trylock_recursive() s390: Use arch_local_irq_{save,restore}() in early boot code lockdep: Noinstr annotate warn_bogus_irq_restore() locking/lockdep: Avoid unmatched unlock locking/rwsem: Remove empty rwsem.h locking/rtmutex: Add missing kernel-doc markup futex: Remove unneeded gotos futex: Change utime parameter to be 'const ... *' lockdep: report broken irq restoration jump_label: Do not profile branch annotations locking: Add Reviewers locking/selftests: Add local_lock inversion tests locking/lockdep: Exclude local_lock_t from IRQ inversions locking/lockdep: Clean up check_redundant() a bit locking/lockdep: Add a skip() function to __bfs() locking/lockdep: Mark local_lock_t locking/selftests: More granular debug_locks_verbose lockdep/selftest: Add wait context selftests tools/memory-model: Fix typo in klitmus7 compatibility table ...
| * \ \ \ Merge branch 'linus' into locking/core, to pick up upstream fixesIngo Molnar2021-02-1279-448/+428
| |\ \ \ \ | | | | | | | | | | | | | | | | | | Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | locking/mutex: Kill mutex_trylock_recursive()Sebastian Andrzej Siewior2021-02-101-25/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There are not users of mutex_trylock_recursive() in tree as of v5.11-rc7. Remove it. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20210210085248.219210-2-bigeasy@linutronix.de
| * | | | | futex: Change utime parameter to be 'const ... *'Alejandro Colomar2021-01-281-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | futex(2) says that 'utime' is a pointer to 'const'. The implementation doesn't use 'const'; however, it _never_ modifies the contents of utime. - futex() either uses 'utime' as a pointer to struct or as a 'u32'. - In case it's used as a 'u32', it makes a copy of it, and of course it is not dereferenced. - In case it's used as a 'struct __kernel_timespec __user *', the pointer is not dereferenced inside the futex() definition, and it is only passed to a function: get_timespec64(), which accepts a 'const struct __kernel_timespec __user *'. [ tglx: Make the same change to the compat syscall and fixup the prototypes. ] Signed-off-by: Alejandro Colomar <alx.manpages@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20201128123945.4592-1-alx.manpages@gmail.com
| * | | | | lockdep: report broken irq restorationMark Rutland2021-01-221-0/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We generally expect local_irq_save() and local_irq_restore() to be paired and sanely nested, and so local_irq_restore() expects to be called with irqs disabled. Thus, within local_irq_restore() we only trace irq flag changes when unmasking irqs. This means that a sequence such as: | local_irq_disable(); | local_irq_save(flags); | local_irq_enable(); | local_irq_restore(flags); ... is liable to break things, as the local_irq_restore() would mask irqs without tracing this change. Similar problems may exist for architectures whose arch_irq_restore() function depends on being called with irqs disabled. We don't consider such sequences to be a good idea, so let's define those as forbidden, and add tooling to detect such broken cases. This patch adds debug code to WARN() when raw_local_irq_restore() is called with irqs enabled. As raw_local_irq_restore() is expected to pair with raw_local_irq_save(), it should never be called with irqs enabled. To avoid the possibility of circular header dependencies between irqflags.h and bug.h, the warning is handled in a separate C file. The new code is all conditional on a new CONFIG_DEBUG_IRQFLAGS symbol which is independent of CONFIG_TRACE_IRQFLAGS. As noted above such cases will confuse lockdep, so CONFIG_DEBUG_LOCKDEP now selects CONFIG_DEBUG_IRQFLAGS. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20210111153707.10071-1-mark.rutland@arm.com
| * | | | | jump_label: Do not profile branch annotationsSteven Rostedt (VMware)2021-01-222-6/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | While running my branch profiler that checks for incorrect "likely" and "unlikely"s around the kernel, there's a large number of them that are incorrect due to being "static_branches". As static_branches are rather special, as they are likely or unlikely for other reasons than normal annotations are used for, there's no reason to have them be profiled. Expose the "unlikely_notrace" and "likely_notrace" so that the static_branch can use them, and have them be ignored by the branch profilers. Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20201211163754.585174b9@gandalf.local.home
| * | | | | locking/lockdep: Mark local_lock_tPeter Zijlstra2021-01-143-8/+30
| | |_|/ / | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The local_lock_t's are special, because they cannot form IRQ inversions, make sure we can tell them apart from the rest of the locks. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
* | | | | Merge tag 'core-rcu-2021-02-17' of ↵Linus Torvalds2021-02-2112-28/+213
|\ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull RCU updates from Ingo Molnar: "These are the latest RCU updates for v5.12: - Documentation updates. - Miscellaneous fixes. - kfree_rcu() updates: Addition of mem_dump_obj() to provide allocator return addresses to more easily locate bugs. This has a couple of RCU-related commits, but is mostly MM. Was pulled in with akpm's agreement. - Per-callback-batch tracking of numbers of callbacks, which enables better debugging information and smarter reactions to large numbers of callbacks. - The first round of changes to allow CPUs to be runtime switched from and to callback-offloaded state. - CONFIG_PREEMPT_RT-related changes. - RCU CPU stall warning updates. - Addition of polling grace-period APIs for SRCU. - Torture-test and torture-test scripting updates, including a "torture everything" script that runs rcutorture, locktorture, scftorture, rcuscale, and refscale. Plus does an allmodconfig build. - nolibc fixes for the torture tests" * tag 'core-rcu-2021-02-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (130 commits) percpu_ref: Dump mem_dump_obj() info upon reference-count underflow rcu: Make call_rcu() print mem_dump_obj() info for double-freed callback mm: Make mem_obj_dump() vmalloc() dumps include start and length mm: Make mem_dump_obj() handle vmalloc() memory mm: Make mem_dump_obj() handle NULL and zero-sized pointers mm: Add mem_dump_obj() to print source of memory block tools/rcutorture: Fix position of -lgcc in mkinitrd.sh tools/nolibc: Fix position of -lgcc in the documented example tools/nolibc: Emit detailed error for missing alternate syscall number definitions tools/nolibc: Remove incorrect definitions of __ARCH_WANT_* tools/nolibc: Get timeval, timespec and timezone from linux/time.h tools/nolibc: Implement poll() based on ppoll() tools/nolibc: Implement fork() based on clone() tools/nolibc: Make getpgrp() fall back to getpgid(0) tools/nolibc: Make dup2() rely on dup3() when available tools/nolibc: Add the definition for dup() rcutorture: Add rcutree.use_softirq=0 to RUDE01 and TASKS01 torture: Maintain torture-specific set of CPUs-online books torture: Clean up after torture-test CPU hotplugging rcutorture: Make object_debug also double call_rcu() heap object ...
| * \ \ \ \ Merge branch 'for-mingo-rcu' of ↵Ingo Molnar2021-02-1212-28/+213
| |\ \ \ \ \ | | |_|/ / / | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu Pull RCU updates from Paul E. McKenney: - Documentation updates. - Miscellaneous fixes. - kfree_rcu() updates: Addition of mem_dump_obj() to provide allocator return addresses to more easily locate bugs. This has a couple of RCU-related commits, but is mostly MM. Was pulled in with akpm's agreement. - Per-callback-batch tracking of numbers of callbacks, which enables better debugging information and smarter reactions to large numbers of callbacks. - The first round of changes to allow CPUs to be runtime switched from and to callback-offloaded state. - CONFIG_PREEMPT_RT-related changes. - RCU CPU stall warning updates. - Addition of polling grace-period APIs for SRCU. - Torture-test and torture-test scripting updates, including a "torture everything" script that runs rcutorture, locktorture, scftorture, rcuscale, and refscale. Plus does an allmodconfig build. Signed-off-by: Ingo Molnar <mingo@kernel.org>
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| | *---------. \ \ \ Merge branches 'doc.2021.01.06a', 'fixes.2021.01.04b', ↵Paul E. McKenney2021-01-2311-27/+218
| | |\ \ \ \ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 'kfree_rcu.2021.01.04a', 'mmdumpobj.2021.01.22a', 'nocb.2021.01.06a', 'rt.2021.01.04a', 'stall.2021.01.06a', 'torture.2021.01.12a' and 'tortureall.2021.01.06a' into HEAD doc.2021.01.06a: Documentation updates. fixes.2021.01.04b: Miscellaneous fixes. kfree_rcu.2021.01.04a: kfree_rcu() updates. mmdumpobj.2021.01.22a: Dump allocation point for memory blocks. nocb.2021.01.06a: RCU callback offload updates and cblist segment lengths. rt.2021.01.04a: Real-time updates. stall.2021.01.06a: RCU CPU stall warning updates. torture.2021.01.12a: Torture-test updates and polling SRCU grace-period API. tortureall.2021.01.06a: Torture-test script updates.
| | | | | | | | * | | | torture: Maintain torture-specific set of CPUs-online booksPaul E. McKenney2021-01-071-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The TREE01 rcutorture scenario intentionally creates confusion as to the number of available CPUs by specifying the "maxcpus=8 nr_cpus=43" kernel boot parameters. This can disable rcutorture's load shedding, which currently uses num_online_cpus(), which would count the extra 35 CPUs. However, the rcutorture guest OS will be provisioned with only 8 CPUs, which means that rcutorture will present full load even when all but one of the original 8 CPUs are offline. This can result in spurious errors due to extreme overloading of that single remaining CPU. This commit therefore keeps a separate set of books on the number of usable online CPUs, so that torture_num_online_cpus() is used for load shedding instead of num_online_cpus(). Note that initial sizing must use num_online_cpus() because torture_num_online_cpus() will return NR_CPUS until shortly after torture_onoff_init() is invoked. Reported-by: Frederic Weisbecker <frederic@kernel.org> [ paulmck: Apply feedback from kernel test robot. ] Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
| | | | | | | | * | | | torture: Throttle VERBOSE_TOROUT_*() outputPaul E. McKenney2021-01-071-2/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This commit adds kernel boot parameters torture.verbose_sleep_frequency and torture.verbose_sleep_duration, which allow VERBOSE_TOROUT_*() output to be throttled with periodic sleeps on large systems. Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
| | | | | | | | * | | | torture: Add fuzzed hrtimer-based sleep functionsPaul E. McKenney2021-01-071-0/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This commit adds torture_hrtimeout_ns(), torture_hrtimeout_us(), torture_hrtimeout_ms(), torture_hrtimeout_jiffies(), and torture_hrtimeout_s(), each of which uses hrtimers to block for a fuzzed time interval. These functions are intended to be used by the various torture tests to decouple wakeups from the timer wheel, thus providing more opportunity for Murphy to insert destructive race conditions. Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
| | | | | | | | * | | | srcu: Provide polling interfaces for Tiny SRCU grace periodsPaul E. McKenney2021-01-043-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There is a need for a polling interface for SRCU grace periods, so this commit supplies get_state_synchronize_srcu(), start_poll_synchronize_srcu(), and poll_state_synchronize_srcu() for this purpose. The first can be used if future grace periods are inevitable (perhaps due to a later call_srcu() invocation), the second if future grace periods might not otherwise happen, and the third to check if a grace period has elapsed since the corresponding call to either of the first two. As with get_state_synchronize_rcu() and cond_synchronize_rcu(), the return value from either get_state_synchronize_srcu() or start_poll_synchronize_srcu() must be passed in to a later call to poll_state_synchronize_srcu(). Link: https://lore.kernel.org/rcu/20201112201547.GF3365678@moria.home.lan/ Reported-by: Kent Overstreet <kent.overstreet@gmail.com> [ paulmck: Add EXPORT_SYMBOL_GPL() per kernel test robot feedback. ] [ paulmck: Apply feedback from Neeraj Upadhyay. ] Link: https://lore.kernel.org/lkml/20201117004017.GA7444@paulmck-ThinkPad-P72/ Reviewed-by: Neeraj Upadhyay <neeraju@codeaurora.org> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
| | | | | | | | * | | | srcu: Make Tiny SRCU use multi-bit grace-period counterPaul E. McKenney2021-01-041-3/+3
| | | | | | | |/ / / / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There is a need for a polling interface for SRCU grace periods. This polling needs to distinguish between an SRCU instance being idle on the one hand or in the middle of a grace period on the other. This commit therefore converts the Tiny SRCU srcu_struct structure's srcu_idx from a defacto boolean to a free-running counter, using the bottom bit to indicate that a grace period is in progress. The second-from-bottom bit is thus used as the index returned by srcu_read_lock(). Link: https://lore.kernel.org/rcu/20201112201547.GF3365678@moria.home.lan/ Reported-by: Kent Overstreet <kent.overstreet@gmail.com> [ paulmck: Fix ->srcu_lock_nesting[] indexing per Neeraj Upadhyay. ] Reviewed-by: Neeraj Upadhyay <neeraju@codeaurora.org> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
| | | | | | * | | | | timer: Add timer_curr_running()Frederic Weisbecker2021-01-071-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This commit adds a timer_curr_running() function that verifies that the current code is running in the context of the specified timer's handler. Cc: Josh Triplett <josh@joshtriplett.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Cc: Joel Fernandes <joel@joelfernandes.org> Cc: Neeraj Upadhyay <neeraju@codeaurora.org> Cc: Thomas Gleixner <tglx@linutronix.de> Tested-by: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
| | | | | | * | | | | cpu/hotplug: Add lockdep_is_cpus_held()Frederic Weisbecker2021-01-071-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This commit adds a lockdep_is_cpus_held() function to verify that the proper locks are held and that various operations are running in the correct context. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Cc: Joel Fernandes <joel@joelfernandes.org> Cc: Neeraj Upadhyay <neeraju@codeaurora.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
| | | | | | * | | | | rcu/nocb: Re-offload supportFrederic Weisbecker2021-01-071-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | To re-offload the callback processing off of a CPU, it is necessary to clear SEGCBLIST_SOFTIRQ_ONLY, set SEGCBLIST_OFFLOADED, and then notify both the CB and GP kthreads so that they both set their own bit flag and start processing the callbacks remotely. The re-offloading worker is then notified that it can stop the RCU_SOFTIRQ handler (or rcuc kthread, as the case may be) from processing the callbacks locally. Ordering must be carefully enforced so that the callbacks that used to be processed locally without locking will have the same ordering properties when they are invoked by the nocb CB and GP kthreads. This commit makes this change. Cc: Josh Triplett <josh@joshtriplett.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Cc: Joel Fernandes <joel@joelfernandes.org> Cc: Neeraj Upadhyay <neeraju@codeaurora.org> Cc: Thomas Gleixner <tglx@linutronix.de> Inspired-by: Paul E. McKenney <paulmck@kernel.org> Tested-by: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Frederic Weisbecker <frederic@kernel.org> [ paulmck: Export rcu_nocb_cpu_offload(). ] Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
| | | | | | * | | | | rcu/nocb: De-offloading CB kthreadFrederic Weisbecker2021-01-071-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | To de-offload callback processing back onto a CPU, it is necessary to clear SEGCBLIST_OFFLOAD and notify the nocb CB kthread, which will then clear its own bit flag and go to sleep to stop handling callbacks. This commit makes that change. It will also be necessary to notify the nocb GP kthread in this same way, which is the subject of a follow-on commit. Cc: Josh Triplett <josh@joshtriplett.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Cc: Joel Fernandes <joel@joelfernandes.org> Cc: Neeraj Upadhyay <neeraju@codeaurora.org> Cc: Thomas Gleixner <tglx@linutronix.de> Inspired-by: Paul E. McKenney <paulmck@kernel.org> Tested-by: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Frederic Weisbecker <frederic@kernel.org> [ paulmck: Add export per kernel test robot feedback. ] Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
| | | | | | * | | | | rcu/nocb: Provide basic callback offloading state machine bitsFrederic Weisbecker2021-01-071-1/+114
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Offloading and de-offloading RCU callback processes must be done carefully. There must never be a time at which callback processing is disabled because the task driving the offloading or de-offloading might be preempted or otherwise stalled at that point in time, which would result in OOM due to calbacks piling up indefinitely. This implies that there will be times during which a given CPU's callbacks might be concurrently invoked by both that CPU's RCU_SOFTIRQ handler (or, equivalently, that CPU's rcuc kthread) and by that CPU's rcuo kthread. This situation could fatally confuse both rcu_barrier() and the CPU-hotplug offlining process, so these must be excluded during any concurrent-callback-invocation period. In addition, during times of concurrent callback invocation, changes to ->cblist must be protected both as needed for RCU_SOFTIRQ and as needed for the rcuo kthread. This commit therefore defines and documents the states for a state machine that coordinates offloading and deoffloading. Cc: Josh Triplett <josh@joshtriplett.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Cc: Joel Fernandes <joel@joelfernandes.org> Cc: Neeraj Upadhyay <neeraju@codeaurora.org> Cc: Thomas Gleixner <tglx@linutronix.de> Inspired-by: Paul E. McKenney <paulmck@kernel.org> Tested-by: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
| | | | | | * | | | | rcu/nocb: Turn enabled/offload states into a common flagFrederic Weisbecker2021-01-071-2/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This commit gathers the rcu_segcblist ->enabled and ->offloaded property field into a single ->flags bitmask to avoid further proliferation of individual u8 fields in the structure. This change prepares for the state formerly known as ->offloaded state to be modified at runtime. Cc: Josh Triplett <josh@joshtriplett.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Cc: Joel Fernandes <joel@joelfernandes.org> Cc: Neeraj Upadhyay <neeraju@codeaurora.org> Cc: Thomas Gleixner <tglx@linutronix.de> Inspired-by: Paul E. McKenney <paulmck@kernel.org> Tested-by: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
| | | | | | * | | | | rcu/trace: Add tracing for how segcb list changesJoel Fernandes (Google)2021-01-071-0/+26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This commit adds tracing to track how the segcb list changes before/after acceleration, during queuing and during dequeuing. This tracing helped discover an optimization that avoided needless GP requests when no callbacks were accelerated. The tracing overhead is minimal as each segment's length is now stored in the respective segment. Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Reviewed-by: Neeraj Upadhyay <neeraju@codeaurora.org> Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
| | | | | | * | | | | rcu/segcblist: Add counters to segcblist datastructureJoel Fernandes (Google)2021-01-071-0/+1
| | | | | | |/ / / / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add counting of segment lengths of segmented callback list. This will be useful for a number of things such as knowing how big the ready-to-execute segment have gotten. The immediate benefit is ability to trace how the callbacks in the segmented callback list change. Also this patch remove hacks related to using donecbs's ->len field as a temporary variable to save the segmented callback list's length. This cannot be done anymore and is not needed. Also fix SRCU: The negative counting of the unsegmented list cannot be used to adjust the segmented one. To fix this, sample the unsegmented length in advance, and use it after CB execution to adjust the segmented list's length. Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
| | | | | * | | | | mm: Make mem_dump_obj() handle vmalloc() memoryPaul E. McKenney2021-01-231-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This commit adds vmalloc() support to mem_dump_obj(). Note that the vmalloc_dump_obj() function combines the checking and dumping, in contrast with the split between kmem_valid_obj() and kmem_dump_obj(). The reason for the difference is that the checking in the vmalloc() case involves acquiring a global lock, and redundant acquisitions of global locks should be avoided, even on not-so-fast paths. Note that this change causes on-stack variables to be reported as vmalloc() storage from kernel_clone() or similar, depending on the degree of inlining that your compiler does. This is likely more helpful than the earlier "non-paged (local) memory". Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: <linux-mm@kvack.org> Reported-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Vlastimil Babka <vbabka@suse.cz> Tested-by: Naresh Kamboju <naresh.kamboju@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>