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
Wang Nan (17):
perf tools: Extract __perf_evlist__mmap_read()
perf tools: Add evlist channel helpers
perf tools: Automatically add new channel according to evlist
perf tools: Operate multiple channels
perf record: Prevent reading invalid data in record__mmap_read
perf tools: Squash overwrite setting into channel
perf record: Don't read from and poll overwrite channel
perf record: Don't poll on overwrite channel
perf tools: Detect avalibility of write_backward
perf tools: Enable overwrite settings
perf tools: Set write_backward attribut bit for overwrite events
perf tools: Record fd into perf_mmap
perf tools: Add API to pause a channel
perf record: Rename variable to make code clear
perf record: Read from backward ring buffer
perf record: Toggle overwrite ring buffer for reading
perf tools: Don't warn about out of order event if write_backward is
used
tools/perf/builtin-record.c | 207 +++++++++++++++++++++++--
tools/perf/perf.h | 2 +
tools/perf/util/evlist.c | 332 ++++++++++++++++++++++++++++++++++++-----
tools/perf/util/evlist.h | 67 ++++++++-
tools/perf/util/evsel.c | 17 +++
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/record.c | 11 ++
tools/perf/util/session.c | 22 ++-
11 files changed, 625 insertions(+), 60 deletions(-)
Cc: Arnaldo Carvalho de Melo <a...@redhat.com>
Cc: He Kuang <heku...@huawei.com>
Cc: Jiri Olsa <jo...@kernel.org>
Cc: Masami Hiramatsu <masami.hiramatsu...@hitachi.com>
Cc: Namhyung Kim <namhy...@kernel.org>
Cc: Peter Zijlstra <pet...@infradead.org>
Cc: Wang Nan <wangn...@huawei.com>
Cc: Zefan Li <lize...@huawei.com>
Cc: pi3or...@163.com
--
1.8.3.4
