Hi,
On 17.06.2020 11:30, Alexey Budankov wrote: > > Changes in v8: > - avoided moving of fds at fdarray__filter() call > - skipped counting of fds with zeroed revents at fdarray__filter() call > - converted explicit --ctl-fd[-ack] into --control fd:ctl-fd[,ack-fd option > - updated docs to accommodate --control fd:ctl-fd[,ack-fd] option Are there any questions or thoughts so far? Thanks, Alexey > > v7: > https://lore.kernel.org/lkml/5de4b954-24f0-1e8d-5a0d-7b12783b8...@linux.intel.com/ > > Changes in v7: > - added missing perf-record.txt changes > - adjusted docs wording for --ctl-fd,ctl-fd-ack options > to additionally mention --delay=-1 effect > > v6: > https://lore.kernel.org/lkml/f8e3a714-d9b1-4647-e1d2-9981cbaa8...@linux.intel.com/ > > Changes in v6: > - split re-factoring of events handling loops for stat mode > into smaller incremental parts > - added parts missing at v5 > - corrected v5 runtime issues > > v5: > https://lore.kernel.org/lkml/e5cac8dd-7aa4-ec7c-671c-07756907a...@linux.intel.com/ > > Changes in v5: > - split re-factoring of events handling loops for stat mode > into smaller incremental parts > > v4: > https://lore.kernel.org/lkml/653fe5f3-c986-a841-1ed8-0a7d2fa24...@linux.intel.com/ > > Changes in v4: > - made checking of ctlfd state unconditional in record trace streaming loop > - introduced static poll fds to keep evlist__filter_pollfd() unaffected > - handled ret code of evlist__initialize_ctlfd() where need > - renamed and structured handle_events() function > - applied anonymous structs where needed > > v3: > https://lore.kernel.org/lkml/eb38e9e5-754f-d410-1d9b-e26b702d5...@linux.intel.com/ > > Changes in v3: > - renamed functions and types from perf_evlist_ to evlist_ to avoid > clash with libperf code; > - extended commands to be strings of variable length consisting of > command name and also possibly including command specific data; > - merged docs update with the code changes; > - updated docs for -D,--delay=-1 option for stat and record modes; > > v2: > https://lore.kernel.org/lkml/d582cc3d-2302-c7e2-70d3-bc7ab6f62...@linux.intel.com/ > > Changes in v2: > - renamed resume and pause commands to enable and disable ones, renamed > CTL_CMD_RESUME and CTL_CMD_PAUSE to CTL_CMD_ENABLE and CTL_CMD_DISABLE > to fit to the appropriate ioctls and avoid mixing up with PAUSE_OUTPUT > ioctl; > - factored out event handling loop into a handle_events() for stat mode; > - separated -D,--delay=-1 into separate patches for stat and record modes; > > v1: > https://lore.kernel.org/lkml/825a5132-b58d-c0b6-b050-5a6040386...@linux.intel.com/ > > repo: tip of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux.git > perf/core > > The patch set implements handling of 'start disabled', 'enable' and 'disable' > external control commands which can be provided for stat and record modes > of the tool from an external controlling process. 'start disabled' command > can be used to postpone enabling of events in the beginning of a monitoring > session. 'enable' and 'disable' commands can be used to enable and disable > events correspondingly any time after the start of the session. > > The 'start disabled', 'enable' and 'disable' external control commands can be > used to focus measurement on specially selected time intervals of workload > execution. Focused measurement reduces tool intrusion and influence on > workload behavior, reduces distortion and amount of collected and stored > data, mitigates data accuracy loss because measurement and data capturing > happen only during intervals of interest. > > A controlling process can be a bash shell script [1], native executable or > any other language program that can directly work with file descriptors, > e.g. pipes [2], and spawn a process, specially the tool one. > > -D,--delay <val> option is extended with -1 value to skip events enabling > in the beginning of a monitoring session ('start disabled' command). > --control fd:ctl-fd[,ack-fd] command line option is introduced to provide the > tool with a pair of file descriptors to listen to control commands and reply > to the controlling process on the completion of received commands. > > The tool reads control command message from ctl-fd descriptor, handles the > command and optionally replies acknowledgement message to ack-fd descriptor, > if it is specified on the command line. 'enable' command is recognized as > 'enable' string message and 'disable' command is recognized as 'disable' > string message both received from ctl-fd descriptor. Completion message is > 'ack\n' and sent to ack-fd descriptor. > > Example bash script demonstrating simple use case follows: > > #!/bin/bash > > ctl_dir=/tmp/ > > ctl_fifo=${ctl_dir}perf_ctl.fifo > test -p ${ctl_fifo} && unlink ${ctl_fifo} > mkfifo ${ctl_fifo} && exec {ctl_fd}<>${ctl_fifo} > > ctl_ack_fifo=${ctl_dir}perf_ctl_ack.fifo > test -p ${ctl_ack_fifo} && unlink ${ctl_ack_fifo} > mkfifo ${ctl_ack_fifo} && exec {ctl_fd_ack}<>${ctl_ack_fifo} > > perf stat -D -1 -e cpu-cycles -a -I 1000 \ > --control fd:${ctl_fd},${ctl_fd_ack} \ > -- sleep 40 & > perf_pid=$! > > sleep 5 && echo 'enable' >&${ctl_fd} && read -u ${ctl_fd_ack} e1 && echo > "enabled(${e1})" > sleep 10 && echo 'disable' >&${ctl_fd} && read -u ${ctl_fd_ack} d1 && echo > "disabled(${d1})" > sleep 5 && echo 'enable' >&${ctl_fd} && read -u ${ctl_fd_ack} e2 && echo > "enabled(${e2})" > sleep 10 && echo 'disable' >&${ctl_fd} && read -u ${ctl_fd_ack} d2 && echo > "disabled(${d2})" > > exec {ctl_fd_ack}>&- && unlink ${ctl_ack_fifo} > exec {ctl_fd}>&- && unlink ${ctl_fifo} > > wait -n ${perf_pid} > exit $? > > > Script output: > > [root@host dir] example > Events disabled > # time counts unit events > 1.001101062 <not counted> cpu-cycles > > 2.002994944 <not counted> cpu-cycles > > 3.004864340 <not counted> cpu-cycles > > 4.006727177 <not counted> cpu-cycles > > Events enabled > enabled(ack) > 4.993808464 3,124,246 cpu-cycles > > 5.008597004 3,325,624 cpu-cycles > > 6.010387483 83,472,992 cpu-cycles > > 7.012266598 55,877,621 cpu-cycles > > 8.014175695 97,892,729 cpu-cycles > > 9.016056093 68,461,242 cpu-cycles > > 10.017937507 55,449,643 cpu-cycles > > 11.019830154 68,938,167 cpu-cycles > > 12.021719952 55,164,101 cpu-cycles > > 13.023627550 70,535,720 cpu-cycles > > 14.025580995 53,240,125 cpu-cycles > > disabled(ack) > 14.997518260 53,558,068 cpu-cycles > > Events disabled > 15.027216416 <not counted> cpu-cycles > > 16.029052729 <not counted> cpu-cycles > > 17.030904762 <not counted> cpu-cycles > > 18.032073424 <not counted> cpu-cycles > > 19.033805074 <not counted> cpu-cycles > > Events enabled > enabled(ack) > 20.001279097 3,021,022 cpu-cycles > > 20.035044381 6,434,367 cpu-cycles > > 21.036923813 89,358,251 cpu-cycles > > 22.038825169 72,516,351 cpu-cycles > > # time counts unit events > 23.040715596 55,046,157 cpu-cycles > > 24.042643757 78,128,649 cpu-cycles > > 25.044558535 61,052,428 cpu-cycles > > 26.046452785 62,142,806 cpu-cycles > > 27.048353021 74,477,971 cpu-cycles > > 28.050241286 61,001,623 cpu-cycles > > 29.052149961 61,653,502 cpu-cycles > > disabled(ack) > 30.004980264 82,729,640 cpu-cycles > > Events disabled > 30.053516176 <not counted> cpu-cycles > > 31.055348366 <not counted> cpu-cycles > > 32.057202097 <not counted> cpu-cycles > > 33.059040702 <not counted> cpu-cycles > > 34.060843288 <not counted> cpu-cycles > > 35.000888624 <not counted> cpu-cycles > > [root@host dir]# > > [1] http://man7.org/linux/man-pages/man1/bash.1.html > [2] http://man7.org/linux/man-pages/man2/pipe.2.html > > --- > Alexey Budankov (13): > tools/libperf: avoid moving of fds at fdarray__filter() call > perf evlist: introduce control file descriptors > perf evlist: implement control command handling functions > perf stat: factor out body of event handling loop for system wide > perf stat: move target check to loop control statement > perf stat: factor out body of event handling loop for fork case > perf stat: factor out event handling loop into dispatch_events() > perf stat: extend -D,--delay option with -1 value > perf stat: implement control commands handling > perf stat: introduce --control fd:ctl-fd[,ack-fd] options > perf record: extend -D,--delay option with -1 value > perf record: implement control commands handling > perf record: introduce --control fd:ctl-fd[,ack-fd] options > > tools/lib/api/fd/array.c | 11 +- > tools/perf/Documentation/perf-record.txt | 44 +++++- > tools/perf/Documentation/perf-stat.txt | 44 +++++- > tools/perf/builtin-record.c | 65 ++++++++- > tools/perf/builtin-stat.c | 176 ++++++++++++++++++----- > tools/perf/builtin-trace.c | 2 +- > tools/perf/tests/fdarray.c | 20 +-- > tools/perf/util/evlist.c | 136 ++++++++++++++++++ > tools/perf/util/evlist.h | 25 ++++ > tools/perf/util/record.h | 4 +- > tools/perf/util/stat.h | 4 +- > 11 files changed, 458 insertions(+), 73 deletions(-) >
