kernel/tools/perf/util/session.c, branch linux-5.2.y

perf session: Fix loading of compressed data split across adjacent records

2019-08-16T08:11:05Z

[ Upstream commit 872c8ee8f0f47222f7b10da96eea84d0486540a3 ] Fix decompression failure found during the loading of compressed trace collected on larger scale systems (>48 cores). The error happened due to lack of decompression space for a mmaped buffer data chunk split across adjacent PERF_RECORD_COMPRESSED records. $ perf report -i bt.16384.data --stats failed to decompress (B): 63869 -> 0 : Destination buffer is too small user stack dump failure Can't parse sample, err = -14 0x2637e436 [0x4080]: failed to process type: 9 Error: failed to process sample $ perf test 71 71: Zstd perf.data compression/decompression : Ok Signed-off-by: Alexey Budankov Acked-by: Jiri Olsa Cc: Alexander Shishkin Cc: Andi Kleen Cc: Namhyung Kim Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/4d839e1b-9c48-89c4-9702-a12217420611@linux.intel.com Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Sasha Levin

perf session: Fix potential NULL pointer dereference found by the smatch tool

2019-07-31T05:24:49Z

[ Upstream commit f3c8d90757724982e5f07cd77d315eb64ca145ac ] Based on the following report from Smatch, fix the potential NULL pointer dereference check. tools/perf/util/session.c:1252 dump_read() error: we previously assumed 'evsel' could be null (see line 1249) tools/perf/util/session.c 1240 static void dump_read(struct perf_evsel *evsel, union perf_event *event) 1241 { 1242 struct read_event *read_event = &event->read; 1243 u64 read_format; 1244 1245 if (!dump_trace) 1246 return; 1247 1248 printf(": %d %d %s %" PRIu64 "\n", event->read.pid, event->read.tid, 1249 evsel ? perf_evsel__name(evsel) : "FAIL", 1250 event->read.value); 1251 1252 read_format = evsel->attr.read_format; ^^^^^^^ 'evsel' could be NULL pointer, for this case this patch directly bails out without dumping read_event. Signed-off-by: Leo Yan Acked-by: Jiri Olsa Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Alexey Budankov Cc: Alexios Zavras Cc: Andi Kleen Cc: Changbin Du Cc: David S. Miller Cc: Davidlohr Bueso Cc: Eric Saint-Etienne Cc: Jin Yao Cc: Konstantin Khlebnikov Cc: Mathieu Poirier Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Rasmus Villemoes Cc: Song Liu Cc: Suzuki Poulouse Cc: Thomas Gleixner Cc: Thomas Richter Cc: linux-arm-kernel@lists.infradead.org Link: http://lkml.kernel.org/r/20190702103420.27540-9-leo.yan@linaro.org Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Sasha Levin

perf session: Add missing swap ops for namespace events

2019-05-28T12:52:23Z

In case it's recorded in a different arch. Signed-off-by: Namhyung Kim Cc: Hari Bathini Cc: Jiri Olsa Cc: Krister Johansen Fixes: f3b3614a284d ("perf tools: Add PERF_RECORD_NAMESPACES to include namespaces related info") Link: http://lkml.kernel.org/r/20190522053250.207156-3-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf report: Implement perf.data record decompression

2019-05-15T19:36:49Z

zstd_init(, comp_level = 0) initializes decompression part of API only hat now consists of zstd_decompress_stream() function. The perf.data PERF_RECORD_COMPRESSED records are decompressed using zstd_decompress_stream() function into a linked list of mmaped memory regions of mmap_comp_len size (struct decomp). After decompression of one COMPRESSED record its content is iterated and fetched for usual processing. The mmaped memory regions with decompressed events are kept in the linked list till the tool process termination. When dumping raw records (e.g., perf report -D --header) file offsets of events from compressed records are printed as zero. Committer notes: Since now we have support for processing PERF_RECORD_COMPRESSED, we see none, in raw form, like we saw in the previous patch commiter notes, they were decompressed into the usual PERF_RECORD_{FORK,MMAP,COMM,etc} records, we only see the stats for those PERF_RECORD_COMPRESSED events, and since I used the file generated in the commiter notes for the previous patch, there they are, 2 compressed records: $ perf report --header-only | grep cmdline # cmdline : /home/acme/bin/perf record -z2 sleep 1 $ perf report -D | grep COMPRESS COMPRESSED events: 2 COMPRESSED events: 0 $ perf report --stdio # To display the perf.data header info, please use --header/--header-only options. # # # Total Lost Samples: 0 # # Samples: 15 of event 'cycles:u' # Event count (approx.): 962227 # # Overhead Command Shared Object Symbol # ........ ....... ................ ........................... # 46.99% sleep libc-2.28.so [.] _dl_addr 29.24% sleep [unknown] [k] 0xffffffffaea00a67 16.45% sleep libc-2.28.so [.] __GI__IO_un_link.part.1 5.92% sleep ld-2.28.so [.] _dl_setup_hash 1.40% sleep libc-2.28.so [.] __nanosleep 0.00% sleep [unknown] [k] 0xffffffffaea00163 # # (Tip: To see callchains in a more compact form: perf report -g folded) # $ Signed-off-by: Alexey Budankov Reviewed-by: Jiri Olsa Tested-by: Arnaldo Carvalho de Melo Cc: Alexander Shishkin Cc: Andi Kleen Cc: Namhyung Kim Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/304b0a59-942c-3fe1-da02-aa749f87108b@linux.intel.com Signed-off-by: Arnaldo Carvalho de Melo

perf report: Add stub processing of compressed events for -D

2019-05-15T19:36:49Z

Committer note: Split from a larger patch, this only dumps PERF_RECORD_COMPRESSED as unhandled, so that when we introduce the record part in the next patch, we don't see unhandled events when using 'perf record -D'. Changed it so that we dump the event if the handler is just a stub, i.e. for the case where we don't have ZSTD linked but we're processing a perf.data file generated by a tool with that linked. Also when failing to decompress we can't just dump the uncompressed event and return 0, we have to propagate the error. Signed-off-by: Alexey Budankov Cc: Alexander Shishkin Cc: Andi Kleen Cc: Namhyung Kim Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/304b0a59-942c-3fe1-da02-aa749f87108b@linux.intel.com Signed-off-by: Arnaldo Carvalho de Melo

perf report: Report OOM in status line in the GTK UI

2019-05-02T20:00:20Z

An -ENOMEM error is not reported in the GTK GUI. Instead this error message pops up on the screen: [root@m35lp76 perf]# ./perf report -i perf.data.error68-1 Processing events... [974K/3M] Error:failed to process sample 0xf4198 [0x8]: failed to process type: 68 However when I use the same perf.data file with --stdio it works: [root@m35lp76 perf]# ./perf report -i perf.data.error68-1 --stdio \ | head -12 # Total Lost Samples: 0 # # Samples: 76K of event 'cycles' # Event count (approx.): 99056160000 # # Overhead Command Shared Object Symbol # ........ ............... ................. ......... # 8.81% find [kernel.kallsyms] [k] ftrace_likely_update 8.74% swapper [kernel.kallsyms] [k] ftrace_likely_update 8.34% sshd [kernel.kallsyms] [k] ftrace_likely_update 2.19% kworker/u512:1- [kernel.kallsyms] [k] ftrace_likely_update The sample precentage is a bit low..... The GUI always fails in the FINISHED_ROUND event (68) and does not indicate the reason why. When happened is the following. Perf report calls a lot of functions and down deep when a FINISHED_ROUND event is processed, these functions are called: perf_session__process_event() + perf_session__process_user_event() + process_finished_round() + ordered_events__flush() + __ordered_events__flush() + do_flush() + ordered_events__deliver_event() + perf_session__deliver_event() + machine__deliver_event() + perf_evlist__deliver_event() + process_sample_event() + hist_entry_iter_add() --> only called in GUI case!!! + hist_iter__report__callback() + symbol__inc_addr_sample() Now this functions runs out of memory and returns -ENOMEM. This is reported all the way up until function perf_session__process_event() returns to its caller, where -ENOMEM is changed to -EINVAL and processing stops: if ((skip = perf_session__process_event(session, event, head)) < 0) { pr_err("%#" PRIx64 " [%#x]: failed to process type: %d\n", head, event->header.size, event->header.type); err = -EINVAL; goto out_err; } This occurred in the FINISHED_ROUND event when it has to process some 10000 entries and ran out of memory. This patch indicates the root cause and displays it in the status line of ther perf report GUI. Output before (on GUI status line): 0xf4198 [0x8]: failed to process type: 68 Output after: 0xf4198 [0x8]: failed to process type: 68 [not enough memory] Committer notes: the 'skip' variable needs to be initialized to -EINVAL, so that when the size is less than sizeof(struct perf_event_attr) we avoid this valid compiler warning: util/session.c: In function ‘perf_session__process_events’: util/session.c:1936:7: error: ‘skip’ may be used uninitialized in this function [-Werror=maybe-uninitialized] err = skip; ~~~~^~~~~~ util/session.c:1874:6: note: ‘skip’ was declared here s64 skip; ^~~~ cc1: all warnings being treated as errors Signed-off-by: Thomas Richter Reviewed-by: Hendrik Brueckner Reviewed-by: Jiri Olsa Cc: Heiko Carstens Cc: Martin Schwidefsky Link: http://lkml.kernel.org/r/20190423105303.61683-1-tmricht@linux.ibm.com Signed-off-by: Arnaldo Carvalho de Melo

perf bpf: Save bpf_prog_info in a rbtree in perf_env

2019-03-19T19:52:06Z

bpf_prog_info contains information necessary to annotate bpf programs. This patch saves bpf_prog_info for bpf programs loaded in the system. Some big picture of the next few patches: To fully annotate BPF programs with source code mapping, 4 different informations are needed: 1) PERF_RECORD_KSYMBOL 2) PERF_RECORD_BPF_EVENT 3) bpf_prog_info 4) btf Before this set, 1) and 2) in the list are already saved to perf.data file. For BPF programs that are already loaded before perf run, 1) and 2) are synthesized by perf_event__synthesize_bpf_events(). For short living BPF programs, 1) and 2) are generated by kernel. This set handles 3) and 4) from the list. Again, it is necessary to handle existing BPF program and short living program separately. This patch handles 3) for exising BPF programs while synthesizing 1) and 2) in perf_event__synthesize_bpf_events(). These data are stored in perf_env. The next patch saves these data from perf_env to perf.data as headers. Similarly, the two patches after the next saves 4) of existing BPF programs to perf_env and perf.data. Another patch later will handle 3) and 4) for short living BPF programs by monitoring 1) and 2) in a dedicate thread. Signed-off-by: Song Liu Reviewed-by: Jiri Olsa Cc: Alexei Starovoitov Cc: Daniel Borkmann Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Stanislav Fomichev Cc: kernel-team@fb.com Link: http://lkml.kernel.org/r/20190312053051.2690567-7-songliubraving@fb.com [ set env->bpf_progs.infos_cnt to zero in perf_env__purge_bpf() as noted by jolsa ] Signed-off-by: Arnaldo Carvalho de Melo

perf session: Add process callback to reader object

2019-03-11T14:56:03Z

Adding callback function to reader object so callers can process data in different ways. Signed-off-by: Jiri Olsa Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Alexey Budankov Cc: Andi Kleen Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Stephane Eranian Link: http://lkml.kernel.org/r/20190308134745.5057-7-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf data: Support having perf.data stored as a directory

2019-03-11T14:56:03Z

The caller needs to set 'struct perf_data::is_dir flag and the path will be treated as a directory. The 'struct perf_data::file' is initialized and open as 'path/header' file. Add a check to the direcory interface functions to check the is_dir flag. Signed-off-by: Jiri Olsa Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Alexey Budankov Cc: Andi Kleen Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Stephane Eranian Link: http://lkml.kernel.org/r/20190308134745.5057-2-jolsa@kernel.org [ Be consistent on how to signal failure, i.e. use -1 and let users check errno ] Signed-off-by: Arnaldo Carvalho de Melo

perf session: Fix double free in perf_data__close

2019-03-06T21:20:33Z

We can't call perf_data__close and subsequently perf_session__delete, because it will call perf_data__close again and cause double free for data->file.path. $ perf report -i . incompatible file format (rerun with -v to learn more) free(): double free detected in tcache 2 Aborted (core dumped) In fact we don't need to call perf_data__close at all, because at the time the got out_close is reached, session->data is already initialized, so the perf_data__close call will be triggered from perf_session__delete. Signed-off-by: Jiri Olsa Cc: Alexander Shishkin Cc: Andi Kleen Cc: Jonas Rabenstein Cc: Nageswara R Sastry Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Ravi Bangoria Fixes: 2d4f27999b88 ("perf data: Add global path holder") Link: http://lkml.kernel.org/r/20190305152536.21035-8-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo