kernel/tools/perf/bench, branch linux-6.17.y

perf symbol: Add blocking argument to filename__read_build_id

2025-08-25T22:07:18Z

When synthesizing build-ids, for build ID mmap2 events, they will be added for data mmaps if -d/--data is specified. The files opened for their build IDs may block on the open causing perf to hang during synthesis. There is some robustness in existing calls to filename__read_build_id by checking the file path is to a regular file, which unfortunately fails for symlinks. Rather than adding more is_regular_file calls, switch filename__read_build_id to take a "block" argument and specify O_NONBLOCK when this is false. The existing is_regular_file checking callers and the event synthesis callers are made to pass false and thereby avoiding the hang. Fixes: 53b00ff358dc ("perf record: Make --buildid-mmap the default") Signed-off-by: Ian Rogers Link: https://lore.kernel.org/r/20250823000024.724394-3-irogers@google.com Signed-off-by: Namhyung Kim

Merge tag 'perf-tools-for-v6.17-2025-08-01' of git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools

2025-08-01T23:55:47Z

Pull perf tools updates from Namhyung Kim: "Build-ID processing goodies: Build-IDs are content based hashes to link regions of memory to ELF files in post processing. They have been available in distros for quite a while: $ file /bin/bash /bin/bash: ELF 64-bit LSB pie executable, x86-64, version 1 (SYSV), dynamically linked, interpreter /lib64/ld-linux-x86-64.so.2, BuildID[sha1]=707a1c670cd72f8e55ffedfbe94ea98901b7ce3a, for GNU/Linux 3.2.0, stripped It is possible to ask the kernel to get it from mmap executable backing storage at time they are being put in place and send it as metadata at that moment to have in perf.data. Prefer that across the board to speed up 'record' time - it post processes the samples to find binaries touched by any samples and to save them with build-ID. It can skip reading build-ID in userspace if it comes from the kernel. perf record: * Make --buildid-mmap default. The kernel can generate MMAP2 events with a build-ID from ELF header. Use that by default instead of using inode and device ID to identify binaries. It also can be disabled with --no-buildid-mmap. * Use BPF for -u/--uid option to sample processes belong to a user. BPF can track user processes more accurately and the existing logic often fails to get the list of processes due to race with reading the /proc filesystem. * Generate PERF_RECORD_BPF_METADATA when it profiles BPF programs and they have variables starting with "bpf_metadata_". This will help to identify BPF objects used in the profile. This has been supported in bpftool for some time and allows the recording of metadata such as commit hashes, versions, etc, that now gets recorded in perf.data as well. * Collect list of DSOs touched in the sample callchains as well as in the sample itself. This would increase the processing time at the end of record, but can improve the data quality. perf stat: * Add a new 'drm' pseudo-PMU support like in 'hwmon'. It can collect DRM usage stats using fdinfo in /proc. On my Intel laptop, it shows like below: $ perf list drm ... drm: drm-active-stolen-system0 [Total memory active in one or more engines. Unit: drm_i915] drm-active-system0 [Total memory active in one or more engines. Unit: drm_i915] drm-engine-capacity-video [Engine capacity. Unit: drm_i915] drm-engine-copy [Utilization in ns. Unit: drm_i915] drm-engine-render [Utilization in ns. Unit: drm_i915] drm-engine-video [Utilization in ns. Unit: drm_i915] ... $ sudo perf stat -a -e drm-engine-render,drm-engine-video,drm-engine-capacity-video sleep 1 Performance counter stats for 'system wide': 48,137,316,988,873 ns drm-engine-render 34,452,696,746 ns drm-engine-video 20 capacity drm-engine-capacity-video 1.002086194 seconds time elapsed perf list * Add description for software events. The description is in JSON format and the event parser now can handle the software events like others (for example, it's case-insensitive and subject to wildcard matching). $ perf list software List of pre-defined events (to be used in -e or -M): software: alignment-faults [Number of kernel handled memory alignment faults. Unit: software] bpf-output [An event used by BPF programs to write to the perf ring buffer. Unit: software] cgroup-switches [Number of context switches to a task in a different cgroup. Unit: software] context-switches [Number of context switches [This event is an alias of cs]. Unit: software] cpu-clock [Per-CPU high-resolution timer based event. Unit: software] cpu-migrations [Number of times a process has migrated to a new CPU [This event is an alias of migrations]. Unit: software] cs [Number of context switches [This event is an alias of context-switches]. Unit: software] dummy [A placeholder event that doesn't count anything. Unit: software] emulation-faults [Number of kernel handled unimplemented instruction faults handled through emulation. Unit: software] faults [Number of page faults [This event is an alias of page-faults]. Unit: software] major-faults [Number of major page faults. Major faults require I/O to handle. Unit: software] migrations [Number of times a process has migrated to a new CPU [This event is an alias of cpu-migrations]. Unit: software] minor-faults [Number of minor page faults. Minor faults don't require I/O to handle. Unit: software] page-faults [Number of page faults [This event is an alias of faults]. Unit: software] task-clock [Per-task high-resolution timer based event. Unit: software] perf ftrace: * Add -e/--events option to perf ftrace latency to measure latency between the two events instead of a function. $ sudo perf ftrace latency -ab -e i915_request_wait_begin,i915_request_wait_end --hide-empty -- sleep 1 # DURATION | COUNT | GRAPH | 256 - 512 us | 4 | ###### | 2 - 4 ms | 2 | ### | 4 - 8 ms | 12 | ################### | 8 - 16 ms | 10 | ################ | # statistics (in usec) total time: 194915 avg time: 6961 max time: 12855 min time: 373 count: 28 * Add new function graph tracer options (--graph-opts) to display more info like arguments and return value. They will be passed to the kernel ftrace directly. $ sudo perf ftrace -G vfs_write --graph-opts retval,retaddr # tracer: function_graph # # CPU DURATION FUNCTION CALLS # | | | | | | | ... 5) | mutex_unlock() { /* <-rb_simple_write+0xda/0x150 */ 5) 0.188 us | local_clock(); /* <-lock_release+0x2ad/0x440 ret=0x3bf2a3cf90e */ 5) | rt_mutex_slowunlock() { /* <-rb_simple_write+0xda/0x150 */ 5) | _raw_spin_lock_irqsave() { /* <-rt_mutex_slowunlock+0x4f/0x200 */ 5) 0.123 us | preempt_count_add(); /* <-_raw_spin_lock_irqsave+0x23/0x90 ret=0x0 */ 5) 0.128 us | local_clock(); /* <-__lock_acquire.isra.0+0x17a/0x740 ret=0x3bf2a3cfc8b */ 5) 0.086 us | do_raw_spin_trylock(); /* <-_raw_spin_lock_irqsave+0x4a/0x90 ret=0x1 */ 5) 0.845 us | } /* _raw_spin_lock_irqsave ret=0x292 */ ... Misc: * Add perf archive --exclude-buildids option to skip some binaries. The format of the FILE should be same as an output of perf buildid-list. * Get rid of dependency of libcrypto. It was just to get SHA-1 hash so implement it directly like in the kernel. A side effect is that it needs -fno-strict-aliasing compiler option (again, like in the kernel). * Convert all shell script tests to use bash" * tag 'perf-tools-for-v6.17-2025-08-01' of git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools: (179 commits) perf record: Cache build-ID of hit DSOs only perf test: Ensure lock contention using pipe mode perf python: Stop using deprecated PyUnicode_AsString() perf list: Skip ABI PMUs when printing pmu values perf list: Remove tracepoint printing code perf tp_pmu: Add event APIs perf tp_pmu: Factor existing tracepoint logic to new file perf parse-events: Remove non-json software events perf jevents: Add common software event json perf tools: Remove libtraceevent in .gitignore perf test: Fix comment ordering perf sort: Use perf_env to set arch sort keys and header perf test: Move PERF_SAMPLE_WEIGHT_STRUCT parsing to common test perf sample: Remove arch notion of sample parsing perf env: Remove global perf_env perf trace: Avoid global perf_env with evsel__env perf auxtrace: Pass perf_env from session through to mmap read perf machine: Explicitly pass in host perf_env perf bench synthesize: Avoid use of global perf_env perf top: Make perf_env locally scoped ...

perf bench synthesize: Avoid use of global perf_env

2025-07-25T17:37:57Z

The benchmark doesn't use a data file and so the header perf_env isn't used. Stack allocate a host perf_env for use to avoid the use of the global perf_env. Signed-off-by: Ian Rogers Link: https://lore.kernel.org/r/20250724163302.596743-16-irogers@google.com Signed-off-by: Namhyung Kim

perf build-id: Ensure struct build_id is empty before use

2025-07-25T17:37:55Z

If a build ID is read then not all code paths may ensure it is empty before use. Initialize the build_id to be zero-ed unless there is clear initialization such as a call to build_id__init. Signed-off-by: Ian Rogers Link: https://lore.kernel.org/r/20250724163302.596743-6-irogers@google.com Signed-off-by: Namhyung Kim

perf bench futex: Remove support for IMMUTABLE

2025-07-11T14:02:01Z

It has been decided to remove the support IMMUTABLE futex. perf bench was one of the eary users for testing purposes. Now that the API is removed before it could be used in an official release, remove the bits from perf, too. Remove Remove support for IMMUTABLE futex. Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Peter Zijlstra (Intel) Link: https://lore.kernel.org/r/20250710110011.384614-7-bigeasy@linutronix.de

Merge tag 'v6.16-rc3' into perf-tools-next

2025-06-23T04:54:03Z

To get the fixes in libbpf and perf tools. Signed-off-by: Namhyung Kim

perf bench futex: Fix prctl include in musl libc

2025-06-17T21:29:42Z

Namhyung Kim reported: I've updated the perf-tools-next to v6.16-rc1 and found a build error like below on alpine linux 3.18. In file included from bench/futex.c:6: /usr/include/sys/prctl.h:88:8: error: redefinition of 'struct prctl_mm_map' 88 | struct prctl_mm_map { | ^~~~~~~~~~~~ In file included from bench/futex.c:5: /linux/tools/include/uapi/linux/prctl.h:134:8: note: originally defined here 134 | struct prctl_mm_map { | ^~~~~~~~~~~~ make[4]: *** [/linux/tools/build/Makefile.build:86: /build/bench/futex.o] Error 1 git bisect says it's the first commit introduced the failure. So both /usr/include/sys/prctl.h and /linux/tools/include/uapi/linux/prctl.h provide struct prctl_mm_map but their include guard must be different. /usr/include/sys/prctl.h provided by glibc contains the prctl() declaration. It includes also linux/prctl.h. The /usr/include/sys/prctl.h on alpine linux is different. This is probably coming from musl. It contains the PR_* definition and the prctl() declaration. So it clashes here because now the one struct is available twice. The man page for prctl(2) says: | #include /* Definition of PR_* constants */ | #include so musl doesn't follow this. So don't include linux/prctl.h explicitely and add some new defines needed if they aren't available. Acked-by: Sebastian Andrzej Siewior Reported-by: Namhyung Kim Closes: https://lore.kernel.org/r/20250611092542.F4ooE2FL@linutronix.de Link: https://www.openwall.com/lists/musl/2025/06/12/11 Signed-off-by: Arnaldo Carvalho de Melo

perf bench evlist-open-close: Switch user option to use BPF filter

2025-06-09T18:18:18Z

Finding user processes by scanning /proc is inherently racy and results in perf_event_open failures. Use a BPF filter to drop samples where the uid doesn't match. Signed-off-by: Ian Rogers Link: https://lore.kernel.org/r/20250604174545.2853620-9-irogers@google.com Signed-off-by: Namhyung Kim

Merge tag 'perf-tools-for-v6.16-1-2025-06-03' of git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools

2025-06-03T22:11:44Z

Pull perf tools updates from Arnaldo Carvalho de Melo: "perf report/top/annotate TUI: - Accept the left arrow key as a Zoom out if done on the first column - Show if source code toggle status in title, to help spotting bugs with the various disassemblers (capstone, llvm, objdump) - Provide feedback on unhandled hotkeys Build: - Better inform when certain features are not available with warnings in the build process and in 'perf version --build-options' or 'perf -vv' perf record: - Improve the --off-cpu code by synthesizing events for switch-out -> switch-in intervals using a BPF program. This can be fine tuned using a --off-cpu-thresh knob perf report: - Add 'tgid' sort key perf mem/c2c: - Add 'op', 'cache', 'snoop', 'dtlb' output fields - Add support for 'ldlat' on AMD IBS (Instruction Based Sampling) perf ftrace: - Use process/session specific trace settings instead of messing with the global ftrace knobs perf trace: - Implement syscall summary in BPF - Support --summary-mode=cgroup - Always print return value for syscalls returning a pid - The rseq and set_robust_list don't return a pid, just -errno perf lock contention: - Symbolize zone->lock using BTF - Add -J/--inject-delay option to estimate impact on application performance by optimization of kernel locking behavior perf stat: - Improve hybrid support for the NMI watchdog warning Symbol resolution: - Handle 'u' and 'l' symbols in /proc/kallsyms, resolving some Rust symbols - Improve Rust demangler Hardware tracing: Intel PT: - Fix PEBS-via-PT data_src - Do not default to recording all switch events - Fix pattern matching with python3 on the SQL viewer script arm64: - Fixups for the hip08 hha PMU Vendor events: - Update Intel events/metrics files for alderlake, alderlaken, arrowlake, bonnell, broadwell, broadwellde, broadwellx, cascadelakex, clearwaterforest, elkhartlake, emeraldrapids, grandridge, graniterapids, haswell, haswellx, icelake, icelakex, ivybridge, ivytown, jaketown, lunarlake, meteorlake, nehalemep, nehalemex, rocketlake, sandybridge, sapphirerapids, sierraforest, skylake, skylakex, snowridgex, tigerlake, westmereep-dp, westmereep-sp, westmereep-sx python support: - Add support for event counts in the python binding, add a counting.py example perf list: - Display the PMU name associated with a perf metric in JSON perf test: - Hybrid improvements for metric value validation test - Fix LBR test by ignoring idle task - Add AMD IBS sw filter ana d'ldlat' tests - Add 'perf trace --summary-mode=cgroup' test - Add tests for the various language symbol demanglers Miscellaneous: - Allow specifying the cpu an event will be tied using '-e event/cpu=N/' - Sync various headers with the kernel sources - Add annotations to use clang's -Wthread-safety and fix some problems it detected - Make dump_stack() use perf's symbol resolution to provide better backtraces - Intel TPEBS support cleanups and fixes. TPEBS stands for Timed PEBS (Precision Event-Based Sampling), that adds timing info, the retirement latency of instructions - Various memory allocation (some detected by ASAN) and reference counting fixes - Add a 8-byte aligned PERF_RECORD_COMPRESSED2 to replace PERF_RECORD_COMPRESSED - Skip unsupported event types in perf.data files, don't stop when finding one - Improve lookups using hashmaps and binary searches" * tag 'perf-tools-for-v6.16-1-2025-06-03' of git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools: (206 commits) perf callchain: Always populate the addr_location map when adding IP perf lock contention: Reject more than 10ms delays for safety perf trace: Set errpid to false for rseq and set_robust_list perf symbol: Move demangling code out of symbol-elf.c perf trace: Always print return value for syscalls returning a pid perf script: Print PERF_AUX_FLAG_COLLISION flag perf mem: Show absolute percent in mem_stat output perf mem: Display sort order only if it's available perf mem: Describe overhead calculation in brief perf record: Fix incorrect --user-regs comments Revert "perf thread: Ensure comm_lock held for comm_list" perf test trace_summary: Skip --bpf-summary tests if no libbpf perf test intel-pt: Skip jitdump test if no libelf perf intel-tpebs: Avoid race when evlist is being deleted perf test demangle-java: Don't segv if demangling fails perf symbol: Fix use-after-free in filename__read_build_id perf pmu: Avoid segv for missing name/alias_name in wildcarding perf machine: Factor creating a "live" machine out of dwarf-unwind perf test: Add AMD IBS sw filter test perf mem: Count L2 HITM for c2c statistic ...

tools headers: Synchronize prctl.h ABI header

2025-05-21T11:57:41Z

The prctl.h ABI header was slightly updated during the development of the interface. In particular the "immutable" parameter became a bit in the option argument. Synchronize prctl.h ABI header again and make use of the definition in the testsuite and "perf bench futex". Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: André Almeida Link: https://lore.kernel.org/r/20250517151455.1065363-5-bigeasy@linutronix.de