linux/tools/lib/perf, branch v6.0

libperf evlist: Fix polling of system-wide events

2022-09-21T19:08:00Z

Originally, (refer commit f90d194a867a5a1d ("perf evlist: Do not poll events that use the system_wide flag") there wasn't much reason to poll system-wide events because: 1. The mmaps get "merged" via set-output anyway (the per-cpu case) 2. perf reads all mmaps when any event is woken 3. system-wide mmaps do not fill up as fast as the mmaps for user selected events But there was 1 reason not to poll which was that it prevented correct termination due to POLLHUP on all user selected events. That issue is now easily resolved by using fdarray_flag__nonfilterable. With the advent of commit ae4f8ae16a078964 ("libperf evlist: Allow mixing per-thread and per-cpu mmaps"), system-wide mmaps can be used also in the per-thread case where reason 1 does not apply. Fix the omission of system-wide events from polling by using the fdarray_flag__nonfilterable flag. Example: Before: $ perf record --no-bpf-event -vvv -e intel_pt// --per-thread uname 2>err.txt Linux $ grep 'sys_perf_event_open.*=\|pollfd' err.txt sys_perf_event_open: pid 155076 cpu -1 group_fd -1 flags 0x8 = 5 sys_perf_event_open: pid 155076 cpu -1 group_fd -1 flags 0x8 = 6 sys_perf_event_open: pid -1 cpu 0 group_fd -1 flags 0x8 = 7 sys_perf_event_open: pid -1 cpu 1 group_fd -1 flags 0x8 = 9 sys_perf_event_open: pid -1 cpu 2 group_fd -1 flags 0x8 = 10 sys_perf_event_open: pid -1 cpu 3 group_fd -1 flags 0x8 = 11 sys_perf_event_open: pid -1 cpu 4 group_fd -1 flags 0x8 = 12 sys_perf_event_open: pid -1 cpu 5 group_fd -1 flags 0x8 = 13 sys_perf_event_open: pid -1 cpu 6 group_fd -1 flags 0x8 = 14 sys_perf_event_open: pid -1 cpu 7 group_fd -1 flags 0x8 = 15 thread_data[0x55fb43c29e80]: pollfd[0] <- event_fd=5 thread_data[0x55fb43c29e80]: pollfd[1] <- event_fd=6 thread_data[0x55fb43c29e80]: pollfd[2] <- non_perf_event fd=4 After: $ perf record --no-bpf-event -vvv -e intel_pt// --per-thread uname 2>err.txt Linux $ grep 'sys_perf_event_open.*=\|pollfd' err.txt sys_perf_event_open: pid 156316 cpu -1 group_fd -1 flags 0x8 = 5 sys_perf_event_open: pid 156316 cpu -1 group_fd -1 flags 0x8 = 6 sys_perf_event_open: pid -1 cpu 0 group_fd -1 flags 0x8 = 7 sys_perf_event_open: pid -1 cpu 1 group_fd -1 flags 0x8 = 9 sys_perf_event_open: pid -1 cpu 2 group_fd -1 flags 0x8 = 10 sys_perf_event_open: pid -1 cpu 3 group_fd -1 flags 0x8 = 11 sys_perf_event_open: pid -1 cpu 4 group_fd -1 flags 0x8 = 12 sys_perf_event_open: pid -1 cpu 5 group_fd -1 flags 0x8 = 13 sys_perf_event_open: pid -1 cpu 6 group_fd -1 flags 0x8 = 14 sys_perf_event_open: pid -1 cpu 7 group_fd -1 flags 0x8 = 15 thread_data[0x55cc19e58e80]: pollfd[0] <- event_fd=5 thread_data[0x55cc19e58e80]: pollfd[1] <- event_fd=6 thread_data[0x55cc19e58e80]: pollfd[2] <- event_fd=7 thread_data[0x55cc19e58e80]: pollfd[3] <- event_fd=9 thread_data[0x55cc19e58e80]: pollfd[4] <- event_fd=10 thread_data[0x55cc19e58e80]: pollfd[5] <- event_fd=11 thread_data[0x55cc19e58e80]: pollfd[6] <- event_fd=12 thread_data[0x55cc19e58e80]: pollfd[7] <- event_fd=13 thread_data[0x55cc19e58e80]: pollfd[8] <- event_fd=14 thread_data[0x55cc19e58e80]: pollfd[9] <- event_fd=15 thread_data[0x55cc19e58e80]: pollfd[10] <- non_perf_event fd=4 Fixes: ae4f8ae16a078964 ("libperf evlist: Allow mixing per-thread and per-cpu mmaps") Signed-off-by: Adrian Hunter Acked-by: Namhyung Kim Cc: Ian Rogers Cc: Jiri Olsa Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20220915122612.81738-3-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo

libperf evlist: Fix per-thread mmaps for multi-threaded targets

2022-09-08T15:17:22Z

The offending commit removed mmap_per_thread(), which did not consider the different set-output rules for per-thread mmaps i.e. in the per-thread case set-output is used for file descriptors of the same thread not the same cpu. This was not immediately noticed because it only happens with multi-threaded targets and we do not have a test for that yet. Reinstate mmap_per_thread() expanding it to cover also system-wide per-cpu events i.e. to continue to allow the mixing of per-thread and per-cpu mmaps. Debug messages (with -vv) show the file descriptors that are opened with sys_perf_event_open. New debug messages are added (needs -vvv) that show also which file descriptors are mmapped and which are redirected with set-output. In the per-cpu case (cpu != -1) file descriptors for the same CPU are set-output to the first file descriptor for that CPU. In the per-thread case (cpu == -1) file descriptors for the same thread are set-output to the first file descriptor for that thread. Example (process 17489 has 2 threads): Before (but with new debug prints): $ perf record --no-bpf-event -vvv --per-thread -p 17489 sys_perf_event_open: pid 17489 cpu -1 group_fd -1 flags 0x8 = 5 sys_perf_event_open: pid 17490 cpu -1 group_fd -1 flags 0x8 = 6 libperf: idx 0: mmapping fd 5 libperf: idx 0: set output fd 6 -> 5 failed to mmap with 22 (Invalid argument) After: $ perf record --no-bpf-event -vvv --per-thread -p 17489 sys_perf_event_open: pid 17489 cpu -1 group_fd -1 flags 0x8 = 5 sys_perf_event_open: pid 17490 cpu -1 group_fd -1 flags 0x8 = 6 libperf: mmap_per_thread: nr cpu values (may include -1) 1 nr threads 2 libperf: idx 0: mmapping fd 5 libperf: idx 1: mmapping fd 6 [ perf record: Woken up 2 times to write data ] [ perf record: Captured and wrote 0.018 MB perf.data (15 samples) ] Per-cpu example (process 20341 has 2 threads, same as above): $ perf record --no-bpf-event -vvv -p 20341 sys_perf_event_open: pid 20341 cpu 0 group_fd -1 flags 0x8 = 5 sys_perf_event_open: pid 20342 cpu 0 group_fd -1 flags 0x8 = 6 sys_perf_event_open: pid 20341 cpu 1 group_fd -1 flags 0x8 = 7 sys_perf_event_open: pid 20342 cpu 1 group_fd -1 flags 0x8 = 8 sys_perf_event_open: pid 20341 cpu 2 group_fd -1 flags 0x8 = 9 sys_perf_event_open: pid 20342 cpu 2 group_fd -1 flags 0x8 = 10 sys_perf_event_open: pid 20341 cpu 3 group_fd -1 flags 0x8 = 11 sys_perf_event_open: pid 20342 cpu 3 group_fd -1 flags 0x8 = 12 sys_perf_event_open: pid 20341 cpu 4 group_fd -1 flags 0x8 = 13 sys_perf_event_open: pid 20342 cpu 4 group_fd -1 flags 0x8 = 14 sys_perf_event_open: pid 20341 cpu 5 group_fd -1 flags 0x8 = 15 sys_perf_event_open: pid 20342 cpu 5 group_fd -1 flags 0x8 = 16 sys_perf_event_open: pid 20341 cpu 6 group_fd -1 flags 0x8 = 17 sys_perf_event_open: pid 20342 cpu 6 group_fd -1 flags 0x8 = 18 sys_perf_event_open: pid 20341 cpu 7 group_fd -1 flags 0x8 = 19 sys_perf_event_open: pid 20342 cpu 7 group_fd -1 flags 0x8 = 20 libperf: mmap_per_cpu: nr cpu values 8 nr threads 2 libperf: idx 0: mmapping fd 5 libperf: idx 0: set output fd 6 -> 5 libperf: idx 1: mmapping fd 7 libperf: idx 1: set output fd 8 -> 7 libperf: idx 2: mmapping fd 9 libperf: idx 2: set output fd 10 -> 9 libperf: idx 3: mmapping fd 11 libperf: idx 3: set output fd 12 -> 11 libperf: idx 4: mmapping fd 13 libperf: idx 4: set output fd 14 -> 13 libperf: idx 5: mmapping fd 15 libperf: idx 5: set output fd 16 -> 15 libperf: idx 6: mmapping fd 17 libperf: idx 6: set output fd 18 -> 17 libperf: idx 7: mmapping fd 19 libperf: idx 7: set output fd 20 -> 19 [ perf record: Woken up 7 times to write data ] [ perf record: Captured and wrote 0.020 MB perf.data (17 samples) ] Fixes: ae4f8ae16a078964 ("libperf evlist: Allow mixing per-thread and per-cpu mmaps") Reported-by: Tomáš Trnka Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=216441 Signed-off-by: Adrian Hunter Acked-by: Jiri Olsa Cc: Adrian Hunter Cc: Ian Rogers Cc: Ingo Molnar Cc: Namhyung Kim Cc: Peter Zijlstra Link: https://lore.kernel.org/r/20220905114209.8389-1-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo

libperf: Add a test case for read formats

2022-08-19T18:56:44Z

It checks a various combination of the read format settings and verify it return the value in a proper position. The test uses task-clock software events to guarantee it's always active and sets enabled/running time. Signed-off-by: Namhyung Kim Acked-by: Jiri Olsa Cc: Ian Rogers Cc: Ingo Molnar Cc: Peter Zijlstra Link: https://lore.kernel.org/r/20220819003644.508916-4-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo

libperf: Handle read format in perf_evsel__read()

2022-08-19T18:56:27Z

The perf_counts_values should be increased to read the new lost data. Also adjust values after read according the read format. This supports PERF_FORMAT_GROUP which has a different data format but it's only available for leader events. Currently it doesn't have an API to read sibling (member) events in the group. But users may read the sibling event directly. Also reading from mmap would be disabled when the read format has ID or LOST bit as it's not exposed via mmap. Signed-off-by: Namhyung Kim Acked-by: Jiri Olsa Cc: Ian Rogers Cc: Ingo Molnar Cc: Peter Zijlstra Link: https://lore.kernel.org/r/20220819003644.508916-3-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf cpumap: Fix alignment for masks in event encoding

2022-08-19T18:30:28Z

A mask encoding of a cpu map is laid out as: u16 nr u16 long_size unsigned long mask[]; However, the mask may be 8-byte aligned meaning there is a 4-byte pad after long_size. This means 32-bit and 64-bit builds see the mask as being at different offsets. On top of this the structure is in the byte data[] encoded as: u16 type char data[] This means the mask's struct isn't the required 4 or 8 byte aligned, but is offset by 2. Consequently the long reads and writes are causing undefined behavior as the alignment is broken. Fix the mask struct by creating explicit 32 and 64-bit variants, use a union to avoid data[] and casts; the struct must be packed so the layout matches the existing perf.data layout. Taking an address of a member of a packed struct breaks alignment so pass the packed perf_record_cpu_map_data to functions, so they can access variables with the right alignment. As the 64-bit version has 4 bytes of padding, optimizing writing to only write the 32-bit version. Committer notes: Disable warnings about 'packed' that break the build in some arches like riscv64, but just around that specific struct. Signed-off-by: Ian Rogers Acked-by: Jiri Olsa Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Alexey Bayduraev Cc: Athira Jajeev Cc: Colin Ian King Cc: Dave Marchevsky Cc: German Gomez Cc: Gustavo A. R. Silva Cc: Ingo Molnar Cc: James Clark Cc: Kees Kook Cc: Leo Yan Cc: Mark Rutland Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Riccardo Mancini Cc: Song Liu Cc: Stephane Eranian Link: https://lore.kernel.org/r/20220614143353.1559597-5-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo

perf cpumap: Const map for max()

2022-08-19T15:26:58Z

Allows max() to be used with 'const struct perf_cpu_maps *'. Signed-off-by: Ian Rogers Acked-by: Jiri Olsa Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Alexey Bayduraev Cc: Athira Jajeev Cc: Colin Ian King Cc: Dave Marchevsky Cc: German Gomez Cc: Gustavo A. R. Silva Cc: Ingo Molnar Cc: James Clark Cc: Kees Kook Cc: Leo Yan Cc: Mark Rutland Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Riccardo Mancini Cc: Song Liu Cc: Stephane Eranian Link: https://lore.kernel.org/r/20220614143353.1559597-2-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo

perf auxtrace: Add machine_pid and vcpu to auxtrace_error

2022-07-20T14:08:17Z

Add machine_pid and vcpu to struct perf_record_auxtrace_error. The existing fmt member is used to identify the new format. The new members make it possible to easily differentiate errors from guest machines. Signed-off-by: Adrian Hunter Acked-by: Ian Rogers Cc: Andi Kleen Cc: Jiri Olsa Cc: Namhyung Kim Cc: kvm@vger.kernel.org Link: https://lore.kernel.org/r/20220711093218.10967-18-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Add machine_pid and vcpu to id_index

2022-07-20T14:07:58Z

When injecting events from a guest perf.data file, the events will have separate sample ID numbers. These ID numbers can then be used to determine which machine an event belongs to. To facilitate that, add machine_pid and vcpu to id_index records. For backward compatibility, these are added at the end of the record, and the length of the record is used to determine if they are present or not. Note, this is needed because the events from a guest perf.data file contain the pid/tid of the process running at that time inside the VM not the pid/tid of the (QEMU) hypervisor thread. So a way is needed to relate guest events back to the guest machine and VCPU, and using sample ID numbers for that is relatively simple and convenient. Signed-off-by: Adrian Hunter Cc: Andi Kleen Cc: Ian Rogers Cc: Jiri Olsa Cc: Namhyung Kim Cc: kvm@vger.kernel.org Link: https://lore.kernel.org/r/20220711093218.10967-11-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo

perf record: Add finished init event

2022-06-23T14:54:22Z

In preparation for recording sideband events in a virtual machine guest so that they can be injected into a host perf.data file. This is needed to enable injecting events after the initial synthesized user events (that have an all zero id sample) but before regular events. Committer notes: Add entry about PERF_RECORD_FINISHED_INIT to tools/perf/Documentation/perf.data-file-format.txt. Committer testing: Before: # perf report -D | grep FINISHED 0 0x5910 [0x8]: PERF_RECORD_FINISHED_ROUND FINISHED_ROUND events: 1 ( 0.5%) # After: # perf record -- sleep 1 [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.020 MB perf.data (7 samples) ] # perf report -D | grep FINISHED 0 0x5068 [0x8]: PERF_RECORD_FINISHED_INIT: unhandled! 0 0x5390 [0x8]: PERF_RECORD_FINISHED_ROUND FINISHED_ROUND events: 1 ( 0.5%) FINISHED_INIT events: 1 ( 0.5%) # Signed-off-by: Adrian Hunter Acked-by: Ian Rogers Tested-by: Arnaldo Carvalho de Melo Cc: Jiri Olsa Cc: Namhyung Kim Link: https://lore.kernel.org/r/20220610113316.6682-5-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo

libperf evsel: Open shouldn't leak fd on failure

2022-06-19T13:41:43Z

If perf_event_open() fails the fd is opened but it is only freed by closing (not by delete). Typically when an open fails you don't call close and so this results in a memory leak. To avoid this, add a close when open fails. Signed-off-by: Ian Rogers Reviewed-By: Kajol Jain Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Andi Kleen Cc: Anshuman Khandual Cc: Ingo Molnar Cc: Jiri Olsa Cc: Mark Rutland Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Rob Herring Cc: Stephane Eranian Link: https://lore.kernel.org/r/20220609052355.1300162-2-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo