Messages in this thread | | | Date | Tue, 15 Dec 2020 16:59:11 +0100 | From | Jiri Olsa <> | Subject | Re: [PATCH 3/3] perf tools: Add evlist/evlist-verbose control commands |
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On Tue, Dec 15, 2020 at 12:23:43PM -0300, Arnaldo Carvalho de Melo wrote: > Em Thu, Dec 10, 2020 at 09:43:30PM +0100, Jiri Olsa escreveu: > > Adding new control events to display all evlist events. > > > > The interface string for control file is 'evlist' and > > 'evlist-verbose'. > > Can't we pass args to such commands? > > Then its just one event, i.e. "evlist", and -v can be passed to it.
it's possible but it adds another processing to the single record thread where we want to be fast
but I agree it could be helpful to get the other output that evsel__fprintf can print, and we already call evsel__fprintf, so it's just a matter of setting 'struct perf_attr_details' properly
I need to check, but perhaps we could use ' ' instead of '-' and have:
echo 'evlist -v' > control echo 'evlist -g' > control echo 'evlist -F' > control
and have:
echo 'enable cycles' > control
instead of:
echo 'enable-cycles' > control
I'd like to avoid any elaborate parsing logic..
how about that?
> > i.e.: > > The commands would be: > > evlist > > That produces: > > > terminal 2: > # echo evlist > control > > terminal 1: > # perf record --control=fifo:control,ack -e 'sched:*' > ... > sched:sched_kthread_stop > sched:sched_kthread_stop_ret > sched:sched_waking > > And 'evlist -v', that produces: > > terminal 2: > # echo "evlist -v" > control > > terminal 1: > ... > sched:sched_kthread_stop: type: 2, size: 120, config: 0x145, \ > { sample_period, sample_freq }: 1, sample_type: IP|TID|TIME|CPU \ > |PERIOD|RAW|IDENTIFIER, read_format: ID, disabled: 1, inherit: \ > 1, sample_id_all: 1, exclude_guest: 1 > sched:sched_kthread_stop_ret: type: 2, size: 120, config: 0x144 \ > , { sample_period, sample_freq }: 1, sample_type: IP|TID|TIME|CPU \ > |PERIOD|RAW|IDENTIFIER, read_format: ID, disabled: 1, inherit: 1, \ > sample_id_all: 1, exclude_guest: 1 > ... > > I think we could even change things such that we pass a file descriptor > for cmd_evlist to use, passing the argv received from the control file, > etc.
hum, so perf evlist opens/reads perf.data, which we do not have ready at that point in perf record
> > With this in place we could reuse more stuff and allow using this > control file to obtain information such as 'perf report --header-only', > etc. > > echo "report --header-only" > control would get us the same thing as > 'perf report --header-only' for an existing perf.data file:
all those header data are written when record is exiting or dumped for switch output, so we don't have that data at that moment control command is received
> > > # perf report --header-only > # ======== > # captured on : Tue Dec 15 12:21:23 2020 > # header version : 1 > # data offset : 432 > # data size : 1648 > # feat offset : 2080 > # hostname : five > # os release : 5.10.0-rc7+ > # perf version : 5.10.rc6.gc56d2601b5d0 > # arch : x86_64 > # nrcpus online : 24 > # nrcpus avail : 24 > # cpudesc : AMD Ryzen 9 3900X 12-Core Processor > # cpuid : AuthenticAMD,23,113,0 > # total memory : 32884432 kB > # cmdline : /home/acme/bin/perf record ls > # event : name = cycles:u, , id = { 85540, 85541, 85542, 85543, 85544, 85545, 85546, 85547, 85548, 85549, 85550, 85551, 85552, 85553, 85554, 85555, 85556, 85557, 85558, 85559, 85560, 85561, 85562, 85563 }, size = 120, { sample_period, sample_freq } = 4000, sample_type = IP|TID|TIME|PERIOD, read_format = ID, disabled = 1, inherit = 1, exclude_kernel = 1, mmap = 1, comm = 1, freq = 1, enable_on_exec = 1, task = 1, sample_id_all = 1, exclude_guest = 1, mmap2 = 1, comm_exec = 1, ksymbol = 1, bpf_event = 1 > # CPU_TOPOLOGY info available, use -I to display > # NUMA_TOPOLOGY info available, use -I to display > # pmu mappings: amd_df = 8, software = 1, ibs_op = 11, power = 14, ibs_fetch = 10, uprobe = 7, cpu = 4, amd_iommu_0 = 12, breakpoint = 5, amd_l3 = 9, tracepoint = 2, kprobe = 6, msr = 13 > # CACHE info available, use -I to display > # time of first sample : 12184.494971 > # time of last sample : 12184.495496 > # sample duration : 0.525 ms > # MEM_TOPOLOGY info available, use -I to display > # cpu pmu capabilities: max_precise=0 > # missing features: TRACING_DATA BRANCH_STACK GROUP_DESC AUXTRACE STAT CLOCKID DIR_FORMAT COMPRESSED CLOCK_DATA > # ======== > # > > I.e. users would discover that using this control file is as easy as > working with perf.data files or with the pipe mode, all the three ways > of interacting with perf would use the same command interface arguments.
yep, I agree we can mimic the similar arguments, but I doubt we can easily reuse the same code for that
jirka
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