kernel/include/linux/perf_event.h, branch linux-5.14.y

perf/core: fix userpage->time_enabled of inactive events

2021-10-17T08:44:51Z

[ Upstream commit f792565326825ed806626da50c6f9a928f1079c1 ] Users of rdpmc rely on the mmapped user page to calculate accurate time_enabled. Currently, userpage->time_enabled is only updated when the event is added to the pmu. As a result, inactive event (due to counter multiplexing) does not have accurate userpage->time_enabled. This can be reproduced with something like: /* open 20 task perf_event "cycles", to create multiplexing */ fd = perf_event_open(); /* open task perf_event "cycles" */ userpage = mmap(fd); /* use mmap and rdmpc */ while (true) { time_enabled_mmap = xxx; /* use logic in perf_event_mmap_page */ time_enabled_read = read(fd).time_enabled; if (time_enabled_mmap > time_enabled_read) BUG(); } Fix this by updating userpage for inactive events in merge_sched_in. Suggested-by: Peter Zijlstra (Intel) Reported-and-tested-by: Lucian Grijincu Signed-off-by: Song Liu Signed-off-by: Peter Zijlstra (Intel) Link: https://lkml.kernel.org/r/20210929194313.2398474-1-songliubraving@fb.com Signed-off-by: Sasha Levin

perf: Add EVENT_ATTR_ID to simplify event attributes

2021-06-11T10:18:40Z

Similar EVENT_ATTR macros are defined in many PMU drivers, like Arm PMU driver, Arm SMMU PMU driver. So add a generic macro to simplify code. Cc: Peter Zijlstra Cc: Ingo Molnar Cc: Arnaldo Carvalho de Melo Cc: Mark Rutland Cc: Alexander Shishkin Signed-off-by: Qi Liu Link: https://lore.kernel.org/r/1623220863-58233-2-git-send-email-liuqi115@huawei.com Signed-off-by: Will Deacon

Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

2021-05-01T17:14:08Z

Pull kvm updates from Paolo Bonzini: "This is a large update by KVM standards, including AMD PSP (Platform Security Processor, aka "AMD Secure Technology") and ARM CoreSight (debug and trace) changes. ARM: - CoreSight: Add support for ETE and TRBE - Stage-2 isolation for the host kernel when running in protected mode - Guest SVE support when running in nVHE mode - Force W^X hypervisor mappings in nVHE mode - ITS save/restore for guests using direct injection with GICv4.1 - nVHE panics now produce readable backtraces - Guest support for PTP using the ptp_kvm driver - Performance improvements in the S2 fault handler x86: - AMD PSP driver changes - Optimizations and cleanup of nested SVM code - AMD: Support for virtual SPEC_CTRL - Optimizations of the new MMU code: fast invalidation, zap under read lock, enable/disably dirty page logging under read lock - /dev/kvm API for AMD SEV live migration (guest API coming soon) - support SEV virtual machines sharing the same encryption context - support SGX in virtual machines - add a few more statistics - improved directed yield heuristics - Lots and lots of cleanups Generic: - Rework of MMU notifier interface, simplifying and optimizing the architecture-specific code - a handful of "Get rid of oprofile leftovers" patches - Some selftests improvements" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (379 commits) KVM: selftests: Speed up set_memory_region_test selftests: kvm: Fix the check of return value KVM: x86: Take advantage of kvm_arch_dy_has_pending_interrupt() KVM: SVM: Skip SEV cache flush if no ASIDs have been used KVM: SVM: Remove an unnecessary prototype declaration of sev_flush_asids() KVM: SVM: Drop redundant svm_sev_enabled() helper KVM: SVM: Move SEV VMCB tracking allocation to sev.c KVM: SVM: Explicitly check max SEV ASID during sev_hardware_setup() KVM: SVM: Unconditionally invoke sev_hardware_teardown() KVM: SVM: Enable SEV/SEV-ES functionality by default (when supported) KVM: SVM: Condition sev_enabled and sev_es_enabled on CONFIG_KVM_AMD_SEV=y KVM: SVM: Append "_enabled" to module-scoped SEV/SEV-ES control variables KVM: SEV: Mask CPUID[0x8000001F].eax according to supported features KVM: SVM: Move SEV module params/variables to sev.c KVM: SVM: Disable SEV/SEV-ES if NPT is disabled KVM: SVM: Free sev_asid_bitmap during init if SEV setup fails KVM: SVM: Zero out the VMCB array used to track SEV ASID association x86/sev: Drop redundant and potentially misleading 'sev_enabled' KVM: x86: Move reverse CPUID helpers to separate header file KVM: x86: Rename GPR accessors to make mode-aware variants the defaults ...

perf: Get rid of oprofile leftovers

2021-04-22T12:32:39Z

perf_pmu_name() and perf_num_counters() are unused. Drop them. Signed-off-by: Marc Zyngier Acked-by: Will Deacon Link: https://lore.kernel.org/r/20210414134409.1266357-6-maz@kernel.org

perf: Extend PERF_TYPE_HARDWARE and PERF_TYPE_HW_CACHE

2021-04-19T18:03:29Z

Current Hardware events and Hardware cache events have special perf types, PERF_TYPE_HARDWARE and PERF_TYPE_HW_CACHE. The two types don't pass the PMU type in the user interface. For a hybrid system, the perf subsystem doesn't know which PMU the events belong to. The first capable PMU will always be assigned to the events. The events never get a chance to run on the other capable PMUs. Extend the two types to become PMU aware types. The PMU type ID is stored at attr.config[63:32]. Add a new PMU capability, PERF_PMU_CAP_EXTENDED_HW_TYPE, to indicate a PMU which supports the extended PERF_TYPE_HARDWARE and PERF_TYPE_HW_CACHE. The PMU type is only required when searching a specific PMU. The PMU specific codes will only be interested in the 'real' config value, which is stored in the low 32 bit of the event->attr.config. Update the event->attr.config in the generic code, so the PMU specific codes don't need to calculate it separately. If a user specifies a PMU type, but the PMU doesn't support the extended type, error out. If an event cannot be initialized in a PMU specified by a user, error out immediately. Perf should not try to open it on other PMUs. The new PMU capability is only set for the X86 hybrid PMUs for now. Other architectures, e.g., ARM, may need it as well. The support on ARM may be implemented later separately. Suggested-by: Peter Zijlstra (Intel) Signed-off-by: Kan Liang Signed-off-by: Peter Zijlstra (Intel) Link: https://lkml.kernel.org/r/1618237865-33448-22-git-send-email-kan.liang@linux.intel.com

perf/x86: Add structures for the attributes of Hybrid PMUs

2021-04-19T18:03:28Z

Hybrid PMUs have different events and formats. In theory, Hybrid PMU specific attributes should be maintained in the dedicated struct x86_hybrid_pmu, but it wastes space because the events and formats are similar among Hybrid PMUs. To reduce duplication, all hybrid PMUs will share a group of attributes in the following patch. To distinguish an attribute from different Hybrid PMUs, a PMU aware attribute structure is introduced. A PMU type is required for the attribute structure. The type is internal usage. It is not visible in the sysfs API. Hybrid PMUs may support the same event name, but with different event encoding, e.g., the mem-loads event on an Atom PMU has different event encoding from a Core PMU. It brings issue if two attributes are created for them. Current sysfs_update_group finds an attribute by searching the attr name (aka event name). If two attributes have the same event name, the first attribute will be replaced. To address the issue, only one attribute is created for the event. The event_str is extended and stores event encodings from all Hybrid PMUs. Each event encoding is divided by ";". The order of the event encodings must follow the order of the hybrid PMU index. The event_str is internal usage as well. When a user wants to show the attribute of a Hybrid PMU, only the corresponding part of the string is displayed. Signed-off-by: Kan Liang Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Andi Kleen Link: https://lkml.kernel.org/r/1618237865-33448-18-git-send-email-kan.liang@linux.intel.com

perf core: Add PERF_COUNT_SW_CGROUP_SWITCHES event

2021-04-16T16:58:52Z

This patch adds a new software event to count context switches involving cgroup switches. So it's counted only if cgroups of previous and next tasks are different. Note that it only checks the cgroups in the perf_event subsystem. For cgroup v2, it shouldn't matter anyway. One can argue that we can do this by using existing sched_switch event with eBPF. But some systems might not have eBPF for some reason so I'd like to add this as a simple way. Signed-off-by: Namhyung Kim Signed-off-by: Peter Zijlstra (Intel) Link: https://lkml.kernel.org/r/20210210083327.22726-2-namhyung@kernel.org

perf core: Factor out __perf_sw_event_sched

2021-04-16T16:58:52Z

In some cases, we need to check more than whether the software event is enabled. So split the condition check and the actual event handling. This is a preparation for the next change. Suggested-by: Peter Zijlstra Signed-off-by: Namhyung Kim Signed-off-by: Peter Zijlstra (Intel) Link: https://lkml.kernel.org/r/20210210083327.22726-1-namhyung@kernel.org

perf: Add support for SIGTRAP on perf events

2021-04-16T14:32:41Z

Adds bit perf_event_attr::sigtrap, which can be set to cause events to send SIGTRAP (with si_code TRAP_PERF) to the task where the event occurred. The primary motivation is to support synchronous signals on perf events in the task where an event (such as breakpoints) triggered. To distinguish perf events based on the event type, the type is set in si_errno. For events that are associated with an address, si_addr is copied from perf_sample_data. The new field perf_event_attr::sig_data is copied to si_perf, which allows user space to disambiguate which event (of the same type) triggered the signal. For example, user space could encode the relevant information it cares about in sig_data. We note that the choice of an opaque u64 provides the simplest and most flexible option. Alternatives where a reference to some user space data is passed back suffer from the problem that modification of referenced data (be it the event fd, or the perf_event_attr) can race with the signal being delivered (of course, the same caveat applies if user space decides to store a pointer in sig_data, but the ABI explicitly avoids prescribing such a design). Suggested-by: Peter Zijlstra Signed-off-by: Marco Elver Signed-off-by: Peter Zijlstra (Intel) Acked-by: Dmitry Vyukov Link: https://lore.kernel.org/lkml/YBv3rAT566k+6zjg@hirez.programming.kicks-ass.net/

perf: Support only inheriting events if cloned with CLONE_THREAD

2021-04-16T14:32:40Z

Adds bit perf_event_attr::inherit_thread, to restricting inheriting events only if the child was cloned with CLONE_THREAD. This option supports the case where an event is supposed to be process-wide only (including subthreads), but should not propagate beyond the current process's shared environment. Suggested-by: Peter Zijlstra Signed-off-by: Marco Elver Signed-off-by: Peter Zijlstra (Intel) Link: https://lore.kernel.org/lkml/YBvj6eJR%2FDY2TsEB@hirez.programming.kicks-ass.net/