kernel.git/tools/perf/builtin-inject.c, branch master

perf inject: With --convert-callchain ignore the dummy event for dwarf stacks

2026-01-23T19:58:39Z

On hybrid systems there is generally >1 event and a dummy event. The perf inject --convert-callchain option is failing to convert perf.data files on such systems reporting "--convert-callchain requires DWARF call graph." The failing event is the dummy event that doesn't need to be set up for samples. As such ignore this event when checking the evsels. Fixes: 92ea788d2af4e65a ("perf inject: Add --convert-callchain option") Signed-off-by: Ian Rogers Tested-by: Arnaldo Carvalho de Melo Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Ingo Molnar Cc: James Clark Cc: Jiri Olsa Cc: Namhyung Kim Cc: Peter Zijlstra Signed-off-by: Arnaldo Carvalho de Melo

perf sched stats: Add record and rawdump support

2026-01-22T15:29:28Z

Define new, perf tool only, sample types and their layouts. Add logic to parse /proc/schedstat, convert it to perf sample format and save samples to perf.data file with `perf sched stats record` command. Also add logic to read perf.data file, interpret schedstat samples and print rawdump of samples with `perf script -D`. Note that, /proc/schedstat file output is standardized with version number. The patch supports v15 but older or newer version can be added easily. Co-developed-by: Ravi Bangoria Signed-off-by: Ravi Bangoria Signed-off-by: Swapnil Sapkal Tested-by: Chen Yu Tested-by: James Clark Acked-by: Ian Rogers Acked-by: Peter Zijlstra Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Andi Kleen Cc: Anubhav Shelat Cc: Ben Gainey Cc: Blake Jones Cc: Chun-Tse Shao Cc: David Vernet Cc: Dmitriy Vyukov Cc: Dr. David Alan Gilbert Cc: Gautham Shenoy Cc: Graham Woodward Cc: Ingo Molnar Cc: James Clark Cc: Jiri Olsa Cc: Juri Lelli Cc: K Prateek Nayak Cc: Kan Liang Cc: Leo Yan Cc: Madadi Vineeth Reddy Cc: Mark Rutland Cc: Namhyung Kim Cc: Sandipan Das Cc: Santosh Shukla Cc: Shrikanth Hegde Cc: Steven Rostedt (VMware) Cc: Tejun Heo Cc: Thomas Falcon Cc: Tim Chen Cc: Vincent Guittot Cc: Yang Jihong Cc: Yujie Liu Cc: Zhongqiu Han [ PRIu64 needs uint64_t, not 'unsigned long' to work on both 32-bit and 64-bit ] Signed-off-by: Arnaldo Carvalho de Melo

perf header: Support CPU DOMAIN relation info

2026-01-22T00:55:09Z

The '/proc/schedstat' file gives info about load balancing statistics within a given domain. It also contains the cpu_mask giving information about the sibling cpus and domain names after schedstat version 17. Storing this information in perf header will help tools like `perf sched stats` for better analysis. Signed-off-by: Swapnil Sapkal Tested-by: Chen Yu Acked-by: Ian Rogers Acked-by: Namhyung Kim Acked-by: Peter Zijlstra Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Andi Kleen Cc: Anubhav Shelat Cc: Ben Gainey Cc: Blake Jones Cc: Chun-Tse Shao Cc: David Vernet Cc: Dmitriy Vyukov Cc: Dr. David Alan Gilbert Cc: Gautham Shenoy Cc: Graham Woodward Cc: Ingo Molnar Cc: James Clark Cc: Jiri Olsa Cc: Juri Lelli Cc: K Prateek Nayak Cc: Kan Liang Cc: Leo Yan Cc: Madadi Vineeth Reddy Cc: Mark Rutland Cc: Ravi Bangoria Cc: Sandipan Das Cc: Santosh Shukla Cc: Shrikanth Hegde Cc: Steven Rostedt (VMware) Cc: Tejun Heo Cc: Thomas Falcon Cc: Tim Chen Cc: Vincent Guittot Cc: Yang Jihong Cc: Yujie Liu Cc: Zhongqiu Han Signed-off-by: Arnaldo Carvalho de Melo

perf inject: Add --convert-callchain option

2026-01-20T20:18:24Z

There are applications not built with frame pointers, so DWARF is needed to get the stack traces. `perf record --call-graph dwarf` saves the stack and register data for each sample to get the stacktrace offline. But sometimes this data may have sensitive information and we don't want to keep them in the file. This new 'perf inject --convert-callchain' option creates the callchains and discards the stack and register after that. This saves storage space and processing time for the new data file. Of course, users should remove the original data file to not keep sensitive data around. :) The down side is that it cannot handle inlined callchain entries as they all have the same IPs. Maybe we can add an option to 'perf report' to look up inlined functions using DWARF - IIUC it doesn't require stack and register data. This is an example. $ perf record --call-graph dwarf -- perf test -w noploop $ perf report --stdio --no-children --percent-limit=0 > output-prev $ perf inject -i perf.data --convert-callchain -o perf.data.out $ perf report --stdio --no-children --percent-limit=0 -i perf.data.out > output-next $ diff -u output-prev output-next ... 0.23% perf ld-linux-x86-64.so.2 [.] _dl_relocate_object_no_relro | - ---elf_dynamic_do_Rela (inlined) - _dl_relocate_object_no_relro + ---_dl_relocate_object_no_relro _dl_relocate_object dl_main _dl_sysdep_start - _dl_start_final (inlined) _dl_start _start Reviewed-by: Ian Rogers Signed-off-by: Namhyung Kim Cc: Adrian Hunter Cc: Ingo Molnar Cc: James Clark Cc: Jiri Olsa Cc: Peter Zijlstra Signed-off-by: Arnaldo Carvalho de Melo

perf inject: Keep build-ID data if no option is used

2026-01-13T20:15:27Z

The keep_feat() determines which header features will be kept or discarded. Usually 'perf inject' will add build-IDs based on -b, -B or other related options. But it lose build-ID when none of those options are used. This is meaningful only when --buildid-mmap is not used. The following example shows the impact of this change. $ perf record --no-buildid-mmap true [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.037 MB perf.data (5 samples) ] $ perf inject -i perf.data -o perf.data.inject $ perf buildid-list -i perf.data 08cccc2a9388d5247ccb3e864f3063b975b0a15d /usr/lib/x86_64-linux-gnu/ld-linux-x86-64.so.2 fd5c4d5673256cd6bda51725dba048dabb0f854e [kernel.kallsyms] 97a36ce1140071be5c36b147fa0bed173e05a602 [vdso] $ perf buildid-list -i perf.data.inject 97a36ce1140071be5c36b147fa0bed173e05a602 [vdso] With this change, perf.data.inject would show the same list (of course, you need to run perf inject again). Reported-by: Gabriel Marin Reviewed-by: Ian Rogers Signed-off-by: Namhyung Kim Cc: Adrian Hunter Cc: Ingo Molnar Cc: James Clark Cc: Jiri Olsa Cc: Peter Zijlstra Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Merge deferred user callchains

2025-12-03T05:59:14Z

Save samples with deferred callchains in a separate list and deliver them after merging the user callchains. If users don't want to merge they can set tool->merge_deferred_callchains to false to prevent the behavior. With previous result, now perf script will show the merged callchains. $ perf script ... pwd 2312 121.163435: 249113 cpu/cycles/P: ffffffff845b78d8 __build_id_parse.isra.0+0x218 ([kernel.kallsyms]) ffffffff83bb5bf6 perf_event_mmap+0x2e6 ([kernel.kallsyms]) ffffffff83c31959 mprotect_fixup+0x1e9 ([kernel.kallsyms]) ffffffff83c31dc5 do_mprotect_pkey+0x2b5 ([kernel.kallsyms]) ffffffff83c3206f __x64_sys_mprotect+0x1f ([kernel.kallsyms]) ffffffff845e6692 do_syscall_64+0x62 ([kernel.kallsyms]) ffffffff8360012f entry_SYSCALL_64_after_hwframe+0x76 ([kernel.kallsyms]) 7f18fe337fa7 mprotect+0x7 (/lib/x86_64-linux-gnu/ld-linux-x86-64.so.2) 7f18fe330e0f _dl_sysdep_start+0x7f (/lib/x86_64-linux-gnu/ld-linux-x86-64.so.2) 7f18fe331448 _dl_start_user+0x0 (/lib/x86_64-linux-gnu/ld-linux-x86-64.so.2) ... The old output can be get using --no-merge-callchain option. Also perf report can get the user callchain entry at the end. $ perf report --no-children --stdio -q -S __build_id_parse.isra.0 # symbol: __build_id_parse.isra.0 8.40% pwd [kernel.kallsyms] | ---__build_id_parse.isra.0 perf_event_mmap mprotect_fixup do_mprotect_pkey __x64_sys_mprotect do_syscall_64 entry_SYSCALL_64_after_hwframe mprotect _dl_sysdep_start _dl_start_user Reviewed-by: Ian Rogers Signed-off-by: Namhyung Kim

perf tools: Don't read build-ids from non-regular files

2025-11-26T18:13:38Z

Simplify the build ID reading code by removing the non-blocking option. Having to pass the correct option to this function was fragile and a mistake would result in a hang, see the linked fix. Furthermore, compressed files are always opened blocking anyway, ignoring the non-blocking option. We also don't expect to read build IDs from non-regular files. The only hits to this function that are non-regular are devices that won't be elf files with build IDs, for example "/dev/dri/renderD129". Now instead of opening these as non-blocking and failing to read, we skip them. Even if something like a pipe or character device did have a build ID, I don't think it would have worked because you need to call read() in a loop, check for -EAGAIN and handle timeouts to make non-blocking reads work. Link: https://lore.kernel.org/linux-perf-users/20251022-james-perf-fix-dso-block-v1-1-c4faab150546@linaro.org/ Signed-off-by: James Clark Signed-off-by: Namhyung Kim

perf build: Remove NO_AUXTRACE build option

2025-11-14T07:03:11Z

The NO_AUXTRACE build option was used when the __get_cpuid feature test failed or if it was provided on the command line. The option no longer avoids a dependency on a library and so having the option is just adding complexity to the code base. Remove the option CONFIG_AUXTRACE from Build files and HAVE_AUXTRACE_SUPPORT by assuming it is always defined. Signed-off-by: Ian Rogers Reviewed-by: James Clark Signed-off-by: Namhyung Kim

perf tool: Add the perf_tool argument to all callbacks

2025-11-07T21:25:05Z

Getting context for what a tool is doing, such as the perf_inject instance, using container_of the tool is a common pattern in the code. This isn't possible event_op2, event_op3 and event_op4 callbacks as the tool isn't passed. Add the argument and then fix function signatures to match. As tools maybe reading a tool from somewhere else, change that code to use the passed in tool. Signed-off-by: Ian Rogers Signed-off-by: Namhyung Kim

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