Messages in this thread | | | Date | Fri, 8 Nov 2019 09:04:40 +0100 | From | Jiri Olsa <> | Subject | Re: [RFC] perf record: Add option to print perf_event_open args and return value |
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On Fri, Nov 08, 2019 at 09:29:49AM +0530, Ravi Bangoria wrote: > Perf record with verbose=2 already prints this information along with > whole lot of other traces which requires lot of scrolling. I thought > to show this information in verbose=1 but I fear that it will be too > much for level 1. So finally created a new option specifically for > printing this. > > Sample o/p: > $ ./perf record --peo-args -- ls > /dev/null > ------------------------------------------------------------ > perf_event_attr: > size 112 > { 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 > precise_ip 3 > sample_id_all 1 > exclude_guest 1 > mmap2 1 > comm_exec 1 > ksymbol 1 > bpf_event 1 > ------------------------------------------------------------ > sys_perf_event_open: pid 4308 cpu 0 group_fd -1 flags 0x8 = 4 > sys_perf_event_open: pid 4308 cpu 1 group_fd -1 flags 0x8 = 5 > sys_perf_event_open: pid 4308 cpu 2 group_fd -1 flags 0x8 = 6 > sys_perf_event_open: pid 4308 cpu 3 group_fd -1 flags 0x8 = 8 > sys_perf_event_open: pid 4308 cpu 4 group_fd -1 flags 0x8 = 9 > sys_perf_event_open: pid 4308 cpu 5 group_fd -1 flags 0x8 = 10 > sys_perf_event_open: pid 4308 cpu 6 group_fd -1 flags 0x8 = 11 > sys_perf_event_open: pid 4308 cpu 7 group_fd -1 flags 0x8 = 12 > ------------------------------------------------------------ > perf_event_attr: > type 1 > size 112 > config 0x9 > watermark 1 > sample_id_all 1 > bpf_event 1 > { wakeup_events, wakeup_watermark } 1 > ------------------------------------------------------------ > sys_perf_event_open: pid -1 cpu 0 group_fd -1 flags 0x8 > sys_perf_event_open failed, error -13 > [ perf record: Woken up 1 times to write data ] > [ perf record: Captured and wrote 0.002 MB perf.data (9 samples) ] > > Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
right, -vv is already poluted ;-) but we have the perf --debug option for specific debug:
--debug Setup debug variable (see list below) in value range (0, 10). Use like: --debug verbose # sets verbose = 1 --debug verbose=2 # sets verbose = 2
List of debug variables allowed to set: verbose - general debug messages ordered-events - ordered events object debug messages data-convert - data convert command debug messages stderr - write debug output (option -v) to stderr in browser mode
so I think something like this would fit better:
perf --debug event-open[=X] record ... perf --debug perf-event-open[=X] record ...
you can have different levels for specific debug output, also it should also stay part of -vv output
thanks, jirka
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