Messages in this thread |  | | From | Wang Nan <> | Subject | [PATCH v16 00/15] perf tools: Support overwritable ring buffer | Date | Thu, 14 Jul 2016 08:34:32 +0000 |
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This patch set enables daemonized perf recording by utilizing overwritable backward ring buffer. With this feature one can put perf background, and dump ring buffer records by a SIGUSR2 when he/she find something unusual. For example, following command record system calls, schedule events and samples on cpu cycles continously:
# perf record -g -e cycles -e raw_syscalls:*/call-graph=no/ \ -e sched:sched_switch/call-graph=no/ \ --switch-output --overwrite -a
Then by sending SIGUSR2 to perf when lagging is happen, we get multiple perf.data output, each of them correspond a abnormal event, and the data size is reasonable:
# ls -l ./perf.data* -rw------- 1 root root 5122165 May 13 23:51 ./perf.data.2016051323511683 -rw------- 1 root root 5135093 May 13 23:51 ./perf.data.2016051323512107 -rw------- 1 root root 5135213 May 13 23:51 ./perf.data.2016051323512215 -rw------- 1 root root 5135157 May 13 23:51 ./perf.data.2016051323512387
v1 -> v2: Totally redesign: drop the principle of 'channal', use auxiliary evlist instead. Fix missing documentation.
v2 -> v3: Rename perf_evlist__toggle_paused() to perf_evlist__pause/resume.
v3 -> v4: Update commit message to describe auxiliary evlist more clearly.
v4 -> v5: Reorder commits, ensure '--overwrite' works right after perf support the option. Add test cases for auxiliary evlist. Avoid bug if main evlist is empty.
v5 -> v6: Improve filter pollfd related code.
v6 -> v7: Rebase to newest perf/core.
v7 -> v8: Unmap mmaps from parent and children in perf_evlist__munmap_filtered(), hide more detail of aux evlist. Add --tail-synthesize, do synthesize at the end of perf.data.
v8 -> v9: Beautify code of test case, make patch set more granular, improve documentation.
v9 -> v10: Make patch set more granular: extract preparation code to patch 1-3.
v10 -> v11: Rebase to newest perf/core: solve conflicts caused by commit e5cadb93d08 ("perf evlist: Rename for_each() macros to for_each_entry()").
v11 -> v12: Improve 'perf test backward': skip this test on old kernel, resolve conflicts.
v12 -> v13: Drop evsel->overwrite, use evsel->attr.write_backward instead.
v13 -> v14: Follow Jiri Olsa's suggestion: Improve commit message, add OVERWRITE_EVT_NOTREADY state, stop the state machine if overwrite_evlist is not generated.
v14 -> v15: Totally redesign: drop auxiliary evlist, use one evlist to contain normal and backward ring buffers (add evlist->backward_mmap). Build new API and helpers for it.
v15 -> v16: Follow Jiri Olsa's suggestion: 1. Move backward ring buffer state machine to evlist. 2. Dynamically allocate backward mmap, so backward_mmap == NULL means there's no backward ring buffer. Stop the state machine when there's no backward ring buffer. 3. Rename: _output2 to _output_backward. 4. Patch rearrangement. 5. Update record__pick_pc(): read from backward_mmap if normal mmap is empty.
Arnaldo Carvalho de Melo (1): perf tools: Drop redundant evsel->overwrite indicator
Wang Nan (14): tools lib fd array: Allow associating a pointer cookie with each entry perf tools: Update perf evlist mmap related APIs and helpers perf tools: Decouple record__mmap_read() and evlist. perf tools: Record mmap cookie into fdarray private field perf tools: Extract common code in mmap failure processing perf tools: Introduce backward_mmap array for evlist perf tools: Map backward events to backward_mmap perf tools: Drop evlist->backward perf tools: Setup backward mmap state machine perf record: Read from overwritable ring buffer perf tools: Make perf_evlist__{pause,resume} internal helpers perf tools: Enable overwrite settings perf tools: Don't warn about out of order event if write_backward is used perf tools: Add --tail-synthesize option
tools/lib/api/fd/array.h | 1 + tools/perf/Documentation/perf-record.txt | 22 +++ tools/perf/builtin-record.c | 113 ++++++++++--- tools/perf/perf.h | 2 + tools/perf/tests/backward-ring-buffer.c | 14 +- tools/perf/util/evlist.c | 270 ++++++++++++++++++++++--------- tools/perf/util/evlist.h | 48 +++++- tools/perf/util/evsel.c | 16 +- tools/perf/util/evsel.h | 3 +- tools/perf/util/parse-events.c | 20 ++- tools/perf/util/parse-events.h | 2 + tools/perf/util/parse-events.l | 2 + tools/perf/util/session.c | 22 ++- 13 files changed, 411 insertions(+), 124 deletions(-)
Signed-off-by: Wang Nan <wangnan0@huawei.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: He Kuang <hekuang@huawei.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Zefan Li <lizefan@huawei.com> Cc: Nilay Vaish <nilayvaish@gmail.com> Cc: pi3orama@163.com -- 1.8.3.4
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