linux.git/include/linux/perf_event.h, branch v6.14-rc2 Linux kernel source tree perf/core: Export perf_exclude_event() 2024-12-09T14:50:31+00:00 Namhyung Kim namhyung@kernel.org 2024-12-03T18:04:40+00:00 6057b90ecc84f232dd32a047a086a4c4c271765f While at it, rename the same function in s390 cpum_sf PMU. Signed-off-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Tested-by: Ravi Bangoria <ravi.bangoria@amd.com> Reviewed-by: Ravi Bangoria <ravi.bangoria@amd.com> Acked-by: Thomas Richter <tmricht@linux.ibm.com> Link: https://lore.kernel.org/r/20241203180441.1634709-2-namhyung@kernel.org 
While at it, rename the same function in s390 cpum_sf PMU.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Ravi Bangoria <ravi.bangoria@amd.com>
Reviewed-by: Ravi Bangoria <ravi.bangoria@amd.com>
Acked-by: Thomas Richter <tmricht@linux.ibm.com>
Link: https://lore.kernel.org/r/20241203180441.1634709-2-namhyung@kernel.org
perf/core: Check sample_type in perf_sample_save_brstack 2024-11-19T08:23:42+00:00 Yabin Cui yabinc@google.com 2024-05-15T19:36:09+00:00 faac6f105ef169e2e5678c14e1ffebf2a7d780b6 Check sample_type in perf_sample_save_brstack() to prevent saving branch stack data when it isn't required. Suggested-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Yabin Cui <yabinc@google.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Ian Rogers <irogers@google.com> Acked-by: Namhyung Kim <namhyung@kernel.org> Link: https://lore.kernel.org/r/20240515193610.2350456-4-yabinc@google.com 
Check sample_type in perf_sample_save_brstack() to prevent
saving branch stack data when it isn't required.

Suggested-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Yabin Cui <yabinc@google.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Ian Rogers <irogers@google.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20240515193610.2350456-4-yabinc@google.com
perf/core: Check sample_type in perf_sample_save_callchain 2024-11-19T08:23:42+00:00 Yabin Cui yabinc@google.com 2024-05-15T19:36:08+00:00 f226805bc5f60adf03783d8e4cbfe303ccecd64e Check sample_type in perf_sample_save_callchain() to prevent saving callchain data when it isn't required. Suggested-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Yabin Cui <yabinc@google.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Ian Rogers <irogers@google.com> Acked-by: Namhyung Kim <namhyung@kernel.org> Link: https://lore.kernel.org/r/20240515193610.2350456-3-yabinc@google.com 
Check sample_type in perf_sample_save_callchain() to prevent
saving callchain data when it isn't required.

Suggested-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Yabin Cui <yabinc@google.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Ian Rogers <irogers@google.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20240515193610.2350456-3-yabinc@google.com
perf/core: Save raw sample data conditionally based on sample type 2024-11-19T08:23:42+00:00 Yabin Cui yabinc@google.com 2024-05-15T19:36:07+00:00 b9c44b91476b67327a521568a854babecc4070ab Currently, space for raw sample data is always allocated within sample records for both BPF output and tracepoint events. This leads to unused space in sample records when raw sample data is not requested. This patch enforces checking sample type of an event in perf_sample_save_raw_data(). So raw sample data will only be saved if explicitly requested, reducing overhead when it is not needed. Fixes: 0a9081cf0a11 ("perf/core: Add perf_sample_save_raw_data() helper") Signed-off-by: Yabin Cui <yabinc@google.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Ian Rogers <irogers@google.com> Acked-by: Namhyung Kim <namhyung@kernel.org> Link: https://lore.kernel.org/r/20240515193610.2350456-2-yabinc@google.com 
Currently, space for raw sample data is always allocated within sample
records for both BPF output and tracepoint events. This leads to unused
space in sample records when raw sample data is not requested.

This patch enforces checking sample type of an event in
perf_sample_save_raw_data(). So raw sample data will only be saved if
explicitly requested, reducing overhead when it is not needed.

Fixes: 0a9081cf0a11 ("perf/core: Add perf_sample_save_raw_data() helper")
Signed-off-by: Yabin Cui <yabinc@google.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Ian Rogers <irogers@google.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20240515193610.2350456-2-yabinc@google.com
perf/core: Correct perf sampling with guest VMs 2024-11-14T09:40:01+00:00 Colton Lewis coltonlewis@google.com 2024-11-13T19:01:55+00:00 2c47e7a74f445426d156278e339b7abb259e50de Previously any PMU overflow interrupt that fired while a VCPU was loaded was recorded as a guest event whether it truly was or not. This resulted in nonsense perf recordings that did not honor perf_event_attr.exclude_guest and recorded guest IPs where it should have recorded host IPs. Rework the sampling logic to only record guest samples for events with exclude_guest = 0. This way any host-only events with exclude_guest set will never see unexpected guest samples. The behaviour of events with exclude_guest = 0 is unchanged. Note that events configured to sample both host and guest may still misattribute a PMI that arrived in the host as a guest event depending on KVM arch and vendor behavior. Signed-off-by: Colton Lewis <coltonlewis@google.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Oliver Upton <oliver.upton@linux.dev> Acked-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Kan Liang <kan.liang@linux.intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Namhyung Kim <namhyung@kernel.org> Link: https://lore.kernel.org/r/20241113190156.2145593-6-coltonlewis@google.com 
Previously any PMU overflow interrupt that fired while a VCPU was
loaded was recorded as a guest event whether it truly was or not. This
resulted in nonsense perf recordings that did not honor
perf_event_attr.exclude_guest and recorded guest IPs where it should
have recorded host IPs.

Rework the sampling logic to only record guest samples for events with
exclude_guest = 0. This way any host-only events with exclude_guest
set will never see unexpected guest samples. The behaviour of events
with exclude_guest = 0 is unchanged.

Note that events configured to sample both host and guest may still
misattribute a PMI that arrived in the host as a guest event depending
on KVM arch and vendor behavior.

Signed-off-by: Colton Lewis <coltonlewis@google.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Kan Liang <kan.liang@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20241113190156.2145593-6-coltonlewis@google.com
perf/core: Hoist perf_instruction_pointer() and perf_misc_flags() 2024-11-14T09:40:01+00:00 Colton Lewis coltonlewis@google.com 2024-11-13T19:01:52+00:00 04782e63917dbcb60932fe93df52c4a4e3859d07 For clarity, rename the arch-specific definitions of these functions to perf_arch_* to denote they are arch-specifc. Define the generic-named functions in one place where they can call the arch-specific ones as needed. Signed-off-by: Colton Lewis <coltonlewis@google.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Oliver Upton <oliver.upton@linux.dev> Acked-by: Thomas Richter <tmricht@linux.ibm.com> Acked-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Madhavan Srinivasan <maddy@linux.ibm.com> Acked-by: Kan Liang <kan.liang@linux.intel.com> Link: https://lore.kernel.org/r/20241113190156.2145593-3-coltonlewis@google.com 
For clarity, rename the arch-specific definitions of these functions
to perf_arch_* to denote they are arch-specifc. Define the
generic-named functions in one place where they can call the
arch-specific ones as needed.

Signed-off-by: Colton Lewis <coltonlewis@google.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Acked-by: Thomas Richter <tmricht@linux.ibm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Acked-by: Kan Liang <kan.liang@linux.intel.com>
Link: https://lore.kernel.org/r/20241113190156.2145593-3-coltonlewis@google.com
perf/core: Add aux_pause, aux_resume, aux_start_paused 2024-11-05T11:55:43+00:00 Adrian Hunter adrian.hunter@intel.com 2024-10-22T15:59:08+00:00 18d92bb57c39504d9da11c6ef604f58eb1d5a117 Hardware traces, such as instruction traces, can produce a vast amount of trace data, so being able to reduce tracing to more specific circumstances can be useful. The ability to pause or resume tracing when another event happens, can do that. Add ability for an event to "pause" or "resume" AUX area tracing. Add aux_pause bit to perf_event_attr to indicate that, if the event happens, the associated AUX area tracing should be paused. Ditto aux_resume. Do not allow aux_pause and aux_resume to be set together. Add aux_start_paused bit to perf_event_attr to indicate to an AUX area event that it should start in a "paused" state. Add aux_paused to struct hw_perf_event for AUX area events to keep track of the "paused" state. aux_paused is initialized to aux_start_paused. Add PERF_EF_PAUSE and PERF_EF_RESUME modes for ->stop() and ->start() callbacks. Call as needed, during __perf_event_output(). Add aux_in_pause_resume to struct perf_buffer to prevent races with the NMI handler. Pause/resume in NMI context will miss out if it coincides with another pause/resume. To use aux_pause or aux_resume, an event must be in a group with the AUX area event as the group leader. Example (requires Intel PT and tools patches also): $ perf record --kcore -e intel_pt/aux-action=start-paused/k,syscalls:sys_enter_newuname/aux-action=resume/,syscalls:sys_exit_newuname/aux-action=pause/ uname Linux [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.043 MB perf.data ] $ perf script --call-trace uname 30805 [000] 24001.058782799: name: 0x7ffc9c1865b0 uname 30805 [000] 24001.058784424: psb offs: 0 uname 30805 [000] 24001.058784424: cbr: 39 freq: 3904 MHz (139%) uname 30805 [000] 24001.058784629: ([kernel.kallsyms]) debug_smp_processor_id uname 30805 [000] 24001.058784629: ([kernel.kallsyms]) __x64_sys_newuname uname 30805 [000] 24001.058784629: ([kernel.kallsyms]) down_read uname 30805 [000] 24001.058784629: ([kernel.kallsyms]) __cond_resched uname 30805 [000] 24001.058784629: ([kernel.kallsyms]) preempt_count_add uname 30805 [000] 24001.058784629: ([kernel.kallsyms]) in_lock_functions uname 30805 [000] 24001.058784629: ([kernel.kallsyms]) preempt_count_sub uname 30805 [000] 24001.058784629: ([kernel.kallsyms]) up_read uname 30805 [000] 24001.058784629: ([kernel.kallsyms]) preempt_count_add uname 30805 [000] 24001.058784838: ([kernel.kallsyms]) in_lock_functions uname 30805 [000] 24001.058784838: ([kernel.kallsyms]) preempt_count_sub uname 30805 [000] 24001.058784838: ([kernel.kallsyms]) _copy_to_user uname 30805 [000] 24001.058784838: ([kernel.kallsyms]) syscall_exit_to_user_mode uname 30805 [000] 24001.058784838: ([kernel.kallsyms]) syscall_exit_work uname 30805 [000] 24001.058784838: ([kernel.kallsyms]) perf_syscall_exit uname 30805 [000] 24001.058784838: ([kernel.kallsyms]) debug_smp_processor_id uname 30805 [000] 24001.058785046: ([kernel.kallsyms]) perf_trace_buf_alloc uname 30805 [000] 24001.058785046: ([kernel.kallsyms]) perf_swevent_get_recursion_context uname 30805 [000] 24001.058785046: ([kernel.kallsyms]) debug_smp_processor_id uname 30805 [000] 24001.058785046: ([kernel.kallsyms]) debug_smp_processor_id uname 30805 [000] 24001.058785046: ([kernel.kallsyms]) perf_tp_event uname 30805 [000] 24001.058785046: ([kernel.kallsyms]) perf_trace_buf_update uname 30805 [000] 24001.058785046: ([kernel.kallsyms]) tracing_gen_ctx_irq_test uname 30805 [000] 24001.058785046: ([kernel.kallsyms]) perf_swevent_event uname 30805 [000] 24001.058785046: ([kernel.kallsyms]) __perf_event_account_interrupt uname 30805 [000] 24001.058785046: ([kernel.kallsyms]) __this_cpu_preempt_check uname 30805 [000] 24001.058785046: ([kernel.kallsyms]) perf_event_output_forward uname 30805 [000] 24001.058785046: ([kernel.kallsyms]) perf_event_aux_pause uname 30805 [000] 24001.058785046: ([kernel.kallsyms]) ring_buffer_get uname 30805 [000] 24001.058785046: ([kernel.kallsyms]) __rcu_read_lock uname 30805 [000] 24001.058785046: ([kernel.kallsyms]) __rcu_read_unlock uname 30805 [000] 24001.058785254: ([kernel.kallsyms]) pt_event_stop uname 30805 [000] 24001.058785254: ([kernel.kallsyms]) debug_smp_processor_id uname 30805 [000] 24001.058785254: ([kernel.kallsyms]) debug_smp_processor_id uname 30805 [000] 24001.058785254: ([kernel.kallsyms]) native_write_msr uname 30805 [000] 24001.058785463: ([kernel.kallsyms]) native_write_msr uname 30805 [000] 24001.058785639: 0x0 Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: James Clark <james.clark@arm.com> Link: https://lkml.kernel.org/r/20241022155920.17511-3-adrian.hunter@intel.com 
Hardware traces, such as instruction traces, can produce a vast amount of
trace data, so being able to reduce tracing to more specific circumstances
can be useful.

The ability to pause or resume tracing when another event happens, can do
that.

Add ability for an event to "pause" or "resume" AUX area tracing.

Add aux_pause bit to perf_event_attr to indicate that, if the event
happens, the associated AUX area tracing should be paused. Ditto
aux_resume. Do not allow aux_pause and aux_resume to be set together.

Add aux_start_paused bit to perf_event_attr to indicate to an AUX area
event that it should start in a "paused" state.

Add aux_paused to struct hw_perf_event for AUX area events to keep track of
the "paused" state. aux_paused is initialized to aux_start_paused.

Add PERF_EF_PAUSE and PERF_EF_RESUME modes for ->stop() and ->start()
callbacks. Call as needed, during __perf_event_output(). Add
aux_in_pause_resume to struct perf_buffer to prevent races with the NMI
handler. Pause/resume in NMI context will miss out if it coincides with
another pause/resume.

To use aux_pause or aux_resume, an event must be in a group with the AUX
area event as the group leader.

Example (requires Intel PT and tools patches also):

 $ perf record --kcore -e intel_pt/aux-action=start-paused/k,syscalls:sys_enter_newuname/aux-action=resume/,syscalls:sys_exit_newuname/aux-action=pause/ uname
 Linux
 [ perf record: Woken up 1 times to write data ]
 [ perf record: Captured and wrote 0.043 MB perf.data ]
 $ perf script --call-trace
 uname   30805 [000] 24001.058782799: name: 0x7ffc9c1865b0
 uname   30805 [000] 24001.058784424:  psb offs: 0
 uname   30805 [000] 24001.058784424:  cbr: 39 freq: 3904 MHz (139%)
 uname   30805 [000] 24001.058784629: ([kernel.kallsyms])        debug_smp_processor_id
 uname   30805 [000] 24001.058784629: ([kernel.kallsyms])        __x64_sys_newuname
 uname   30805 [000] 24001.058784629: ([kernel.kallsyms])            down_read
 uname   30805 [000] 24001.058784629: ([kernel.kallsyms])                __cond_resched
 uname   30805 [000] 24001.058784629: ([kernel.kallsyms])                preempt_count_add
 uname   30805 [000] 24001.058784629: ([kernel.kallsyms])                    in_lock_functions
 uname   30805 [000] 24001.058784629: ([kernel.kallsyms])                preempt_count_sub
 uname   30805 [000] 24001.058784629: ([kernel.kallsyms])            up_read
 uname   30805 [000] 24001.058784629: ([kernel.kallsyms])                preempt_count_add
 uname   30805 [000] 24001.058784838: ([kernel.kallsyms])                    in_lock_functions
 uname   30805 [000] 24001.058784838: ([kernel.kallsyms])                preempt_count_sub
 uname   30805 [000] 24001.058784838: ([kernel.kallsyms])            _copy_to_user
 uname   30805 [000] 24001.058784838: ([kernel.kallsyms])        syscall_exit_to_user_mode
 uname   30805 [000] 24001.058784838: ([kernel.kallsyms])            syscall_exit_work
 uname   30805 [000] 24001.058784838: ([kernel.kallsyms])                perf_syscall_exit
 uname   30805 [000] 24001.058784838: ([kernel.kallsyms])                    debug_smp_processor_id
 uname   30805 [000] 24001.058785046: ([kernel.kallsyms])                    perf_trace_buf_alloc
 uname   30805 [000] 24001.058785046: ([kernel.kallsyms])                        perf_swevent_get_recursion_context
 uname   30805 [000] 24001.058785046: ([kernel.kallsyms])                            debug_smp_processor_id
 uname   30805 [000] 24001.058785046: ([kernel.kallsyms])                        debug_smp_processor_id
 uname   30805 [000] 24001.058785046: ([kernel.kallsyms])                    perf_tp_event
 uname   30805 [000] 24001.058785046: ([kernel.kallsyms])                        perf_trace_buf_update
 uname   30805 [000] 24001.058785046: ([kernel.kallsyms])                            tracing_gen_ctx_irq_test
 uname   30805 [000] 24001.058785046: ([kernel.kallsyms])                        perf_swevent_event
 uname   30805 [000] 24001.058785046: ([kernel.kallsyms])                            __perf_event_account_interrupt
 uname   30805 [000] 24001.058785046: ([kernel.kallsyms])                                __this_cpu_preempt_check
 uname   30805 [000] 24001.058785046: ([kernel.kallsyms])                            perf_event_output_forward
 uname   30805 [000] 24001.058785046: ([kernel.kallsyms])                                perf_event_aux_pause
 uname   30805 [000] 24001.058785046: ([kernel.kallsyms])                                    ring_buffer_get
 uname   30805 [000] 24001.058785046: ([kernel.kallsyms])                                        __rcu_read_lock
 uname   30805 [000] 24001.058785046: ([kernel.kallsyms])                                        __rcu_read_unlock
 uname   30805 [000] 24001.058785254: ([kernel.kallsyms])                                    pt_event_stop
 uname   30805 [000] 24001.058785254: ([kernel.kallsyms])                                        debug_smp_processor_id
 uname   30805 [000] 24001.058785254: ([kernel.kallsyms])                                        debug_smp_processor_id
 uname   30805 [000] 24001.058785254: ([kernel.kallsyms])                                        native_write_msr
 uname   30805 [000] 24001.058785463: ([kernel.kallsyms])                                        native_write_msr
 uname   30805 [000] 24001.058785639: 0x0

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: James Clark <james.clark@arm.com>
Link: https://lkml.kernel.org/r/20241022155920.17511-3-adrian.hunter@intel.com
Merge tag 'perf-core-2024-09-18' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2024-09-18T13:03:58+00:00 Linus Torvalds torvalds@linux-foundation.org 2024-09-18T13:03:58+00:00 9f0c253ddddca608457a42e509267bed2dee0a50 Pull perf events updates from Ingo Molnar: - Implement per-PMU context rescheduling to significantly improve single-PMU performance, and related cleanups/fixes (Peter Zijlstra and Namhyung Kim) - Fix ancient bug resulting in a lot of events being dropped erroneously at higher sampling frequencies (Luo Gengkun) - uprobes enhancements: - Implement RCU-protected hot path optimizations for better performance: "For baseline vs SRCU, peak througput increased from 3.7 M/s (million uprobe triggerings per second) up to about 8 M/s. For uretprobes it's a bit more modest with bump from 2.4 M/s to 5 M/s. For SRCU vs RCU Tasks Trace, peak throughput for uprobes increases further from 8 M/s to 10.3 M/s (+28%!), and for uretprobes from 5.3 M/s to 5.8 M/s (+11%), as we have more work to do on uretprobes side. Even single-thread (no contention) performance is slightly better: 3.276 M/s to 3.396 M/s (+3.5%) for uprobes, and 2.055 M/s to 2.174 M/s (+5.8%) for uretprobes." (Andrii Nakryiko et al) - Document mmap_lock, don't abuse get_user_pages_remote() (Oleg Nesterov) - Cleanups & fixes to prepare for future work: - Remove uprobe_register_refctr() - Simplify error handling for alloc_uprobe() - Make uprobe_register() return struct uprobe * - Fold __uprobe_unregister() into uprobe_unregister() - Shift put_uprobe() from delete_uprobe() to uprobe_unregister() - BPF: Fix use-after-free in bpf_uprobe_multi_link_attach() (Oleg Nesterov) - New feature & ABI extension: allow events to use PERF_SAMPLE READ with inheritance, enabling sample based profiling of a group of counters over a hierarchy of processes or threads (Ben Gainey) - Intel uncore & power events updates: - Add Arrow Lake and Lunar Lake support - Add PERF_EV_CAP_READ_SCOPE - Clean up and enhance cpumask and hotplug support (Kan Liang) - Add LNL uncore iMC freerunning support - Use D0:F0 as a default device (Zhenyu Wang) - Intel PT: fix AUX snapshot handling race (Adrian Hunter) - Misc fixes and cleanups (James Clark, Jiri Olsa, Oleg Nesterov and Peter Zijlstra) * tag 'perf-core-2024-09-18' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (40 commits) dmaengine: idxd: Clean up cpumask and hotplug for perfmon iommu/vt-d: Clean up cpumask and hotplug for perfmon perf/x86/intel/cstate: Clean up cpumask and hotplug perf: Add PERF_EV_CAP_READ_SCOPE perf: Generic hotplug support for a PMU with a scope uprobes: perform lockless SRCU-protected uprobes_tree lookup rbtree: provide rb_find_rcu() / rb_find_add_rcu() perf/uprobe: split uprobe_unregister() uprobes: travers uprobe's consumer list locklessly under SRCU protection uprobes: get rid of enum uprobe_filter_ctx in uprobe filter callbacks uprobes: protected uprobe lifetime with SRCU uprobes: revamp uprobe refcounting and lifetime management bpf: Fix use-after-free in bpf_uprobe_multi_link_attach() perf/core: Fix small negative period being ignored perf: Really fix event_function_call() locking perf: Optimize __pmu_ctx_sched_out() perf: Add context time freeze perf: Fix event_function_call() locking perf: Extract a few helpers perf: Optimize context reschedule for single PMU cases ... 
Pull perf events updates from Ingo Molnar:

 - Implement per-PMU context rescheduling to significantly improve
   single-PMU performance, and related cleanups/fixes (Peter Zijlstra
   and Namhyung Kim)

 - Fix ancient bug resulting in a lot of events being dropped
   erroneously at higher sampling frequencies (Luo Gengkun)

 - uprobes enhancements:

     - Implement RCU-protected hot path optimizations for better
       performance:

         "For baseline vs SRCU, peak througput increased from 3.7 M/s
          (million uprobe triggerings per second) up to about 8 M/s. For
          uretprobes it's a bit more modest with bump from 2.4 M/s to
          5 M/s.

          For SRCU vs RCU Tasks Trace, peak throughput for uprobes
          increases further from 8 M/s to 10.3 M/s (+28%!), and for
          uretprobes from 5.3 M/s to 5.8 M/s (+11%), as we have more
          work to do on uretprobes side.

          Even single-thread (no contention) performance is slightly
          better: 3.276 M/s to 3.396 M/s (+3.5%) for uprobes, and 2.055
          M/s to 2.174 M/s (+5.8%) for uretprobes."

          (Andrii Nakryiko et al)

     - Document mmap_lock, don't abuse get_user_pages_remote() (Oleg
       Nesterov)

     - Cleanups & fixes to prepare for future work:
        - Remove uprobe_register_refctr()
	- Simplify error handling for alloc_uprobe()
        - Make uprobe_register() return struct uprobe *
        - Fold __uprobe_unregister() into uprobe_unregister()
        - Shift put_uprobe() from delete_uprobe() to uprobe_unregister()
        - BPF: Fix use-after-free in bpf_uprobe_multi_link_attach()
          (Oleg Nesterov)

 - New feature & ABI extension: allow events to use PERF_SAMPLE READ
   with inheritance, enabling sample based profiling of a group of
   counters over a hierarchy of processes or threads (Ben Gainey)

 - Intel uncore & power events updates:

      - Add Arrow Lake and Lunar Lake support
      - Add PERF_EV_CAP_READ_SCOPE
      - Clean up and enhance cpumask and hotplug support
        (Kan Liang)

      - Add LNL uncore iMC freerunning support
      - Use D0:F0 as a default device
        (Zhenyu Wang)

 - Intel PT: fix AUX snapshot handling race (Adrian Hunter)

 - Misc fixes and cleanups (James Clark, Jiri Olsa, Oleg Nesterov and
   Peter Zijlstra)

* tag 'perf-core-2024-09-18' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (40 commits)
  dmaengine: idxd: Clean up cpumask and hotplug for perfmon
  iommu/vt-d: Clean up cpumask and hotplug for perfmon
  perf/x86/intel/cstate: Clean up cpumask and hotplug
  perf: Add PERF_EV_CAP_READ_SCOPE
  perf: Generic hotplug support for a PMU with a scope
  uprobes: perform lockless SRCU-protected uprobes_tree lookup
  rbtree: provide rb_find_rcu() / rb_find_add_rcu()
  perf/uprobe: split uprobe_unregister()
  uprobes: travers uprobe's consumer list locklessly under SRCU protection
  uprobes: get rid of enum uprobe_filter_ctx in uprobe filter callbacks
  uprobes: protected uprobe lifetime with SRCU
  uprobes: revamp uprobe refcounting and lifetime management
  bpf: Fix use-after-free in bpf_uprobe_multi_link_attach()
  perf/core: Fix small negative period being ignored
  perf: Really fix event_function_call() locking
  perf: Optimize __pmu_ctx_sched_out()
  perf: Add context time freeze
  perf: Fix event_function_call() locking
  perf: Extract a few helpers
  perf: Optimize context reschedule for single PMU cases
  ...
perf: Add PERF_EV_CAP_READ_SCOPE 2024-09-10T09:44:13+00:00 Kan Liang kan.liang@linux.intel.com 2024-08-02T15:16:38+00:00 a48a36b316ae5d3ab83f9b545dba15998e96d59c Usually, an event can be read from any CPU of the scope. It doesn't need to be read from the advertised CPU. Add a new event cap, PERF_EV_CAP_READ_SCOPE. An event of a PMU with scope can be read from any active CPU in the scope. Signed-off-by: Kan Liang <kan.liang@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20240802151643.1691631-3-kan.liang@linux.intel.com 
Usually, an event can be read from any CPU of the scope. It doesn't need
to be read from the advertised CPU.

Add a new event cap, PERF_EV_CAP_READ_SCOPE. An event of a PMU with
scope can be read from any active CPU in the scope.

Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20240802151643.1691631-3-kan.liang@linux.intel.com
perf: Generic hotplug support for a PMU with a scope 2024-09-10T09:44:12+00:00 Kan Liang kan.liang@linux.intel.com 2024-08-02T15:16:37+00:00 4ba4f1afb6a9fed8ef896c2363076e36572f71da The perf subsystem assumes that the counters of a PMU are per-CPU. So the user space tool reads a counter from each CPU in the system wide mode. However, many PMUs don't have a per-CPU counter. The counter is effective for a scope, e.g., a die or a socket. To address this, a cpumask is exposed by the kernel driver to restrict to one CPU to stand for a specific scope. In case the given CPU is removed, the hotplug support has to be implemented for each such driver. The codes to support the cpumask and hotplug are very similar. - Expose a cpumask into sysfs - Pickup another CPU in the same scope if the given CPU is removed. - Invoke the perf_pmu_migrate_context() to migrate to a new CPU. - In event init, always set the CPU in the cpumask to event->cpu Similar duplicated codes are implemented for each such PMU driver. It would be good to introduce a generic infrastructure to avoid such duplication. 5 popular scopes are implemented here, core, die, cluster, pkg, and the system-wide. The scope can be set when a PMU is registered. If so, a "cpumask" is automatically exposed for the PMU. The "cpumask" is from the perf_online_<scope>_mask, which is to track the active CPU for each scope. They are set when the first CPU of the scope is online via the generic perf hotplug support. When a corresponding CPU is removed, the perf_online_<scope>_mask is updated accordingly and the PMU will be moved to a new CPU from the same scope if possible. Signed-off-by: Kan Liang <kan.liang@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20240802151643.1691631-2-kan.liang@linux.intel.com 
The perf subsystem assumes that the counters of a PMU are per-CPU. So
the user space tool reads a counter from each CPU in the system wide
mode. However, many PMUs don't have a per-CPU counter. The counter is
effective for a scope, e.g., a die or a socket. To address this, a
cpumask is exposed by the kernel driver to restrict to one CPU to stand
for a specific scope. In case the given CPU is removed,
the hotplug support has to be implemented for each such driver.

The codes to support the cpumask and hotplug are very similar.
- Expose a cpumask into sysfs
- Pickup another CPU in the same scope if the given CPU is removed.
- Invoke the perf_pmu_migrate_context() to migrate to a new CPU.
- In event init, always set the CPU in the cpumask to event->cpu

Similar duplicated codes are implemented for each such PMU driver. It
would be good to introduce a generic infrastructure to avoid such
duplication.

5 popular scopes are implemented here, core, die, cluster, pkg, and
the system-wide. The scope can be set when a PMU is registered. If so, a
"cpumask" is automatically exposed for the PMU.

The "cpumask" is from the perf_online_<scope>_mask, which is to track
the active CPU for each scope. They are set when the first CPU of the
scope is online via the generic perf hotplug support. When a
corresponding CPU is removed, the perf_online_<scope>_mask is updated
accordingly and the PMU will be moved to a new CPU from the same scope
if possible.

Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20240802151643.1691631-2-kan.liang@linux.intel.com