Messages in this thread |  | | Date | Wed, 15 Apr 2015 10:20:08 -0600 | From | David Ahern <> | Subject | perf/tracepoints access to interpreted strings |
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Hi Steve:
I was hoping you could provide points on how to get access to an interpreted field in a tracepoint within perf.
This is an example of the tracepoint:
# cat /sys/kernel/debug/tracing/events/irq/softirq_exit/format name: softirq_exit ID: 99 format: field:unsigned short common_type; offset:0; size:2; signed:0; field:unsigned char common_flags; offset:2; size:1; signed:0; field:unsigned char common_preempt_count; offset:3; size:1; signed:0; field:int common_pid; offset:4; size:4; signed:1; field:int common_padding; offset:8; size:4; signed:1;
field:unsigned int vec; offset:12; size:4; signed:0;
print fmt: "vec=%u [action=%s]", REC->vec, __print_symbolic(REC->vec, { HI_SOFTIRQ, "HI" }, { TIMER_SOFTIRQ, "TIMER" }, { NET_TX_SOFTIRQ, "NET_TX" }, { NET_RX_SOFTIRQ, "NET_RX" }, { BLOCK_SOFTIRQ, "BLOCK" }, { BLOCK_IOPOLL_SOFTIRQ, "BLOCK_IOPOLL" }, { TASKLET_SOFTIRQ, "TASKLET" }, { SCHED_SOFTIRQ, "SCHED" }, { HRTIMER_SOFTIRQ, "HRTIMER" }, { RCU_SOFTIRQ, "RCU" })
I would like to programmatically extract the action string. 'perf script' prints the samples fine which suggests libtraceevent extracts the information somehow.
Can you provide a suggestion -- something along the lines of perf_evsel__intval() or perf_evsel__rawptr()?
Thanks, David
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