G'Day perf users, Is there a way to filter perf from tracing itself?
Here's an idle system: # ./perf record -e syscalls:sys_enter_read -a sleep 5 [ perf record: Woken up 2 times to write data ] [ perf record: Captured and wrote 0.569 MB perf.data (~24864 samples) ] # ./perf record -e syscalls:sys_enter_write -a sleep 5 [ perf record: Woken up 0 times to write data ] [ perf record: Captured and wrote 150.381 MB perf.data (~6570251 samples) ] Note the disparity. perf is capturing its own writes, creating a feedback loop. I haven't seen a way to filter this. Eg: # ./perf record -q -e syscalls:sys_enter_write --filter 'comm != perf' -a sleep 5 Error: failed to set filter with 22 (Invalid argument) # ./perf record -q -e syscalls:sys_enter_write --filter 'ppid != '$$ -a sleep 5 Error: failed to set filter with 22 (Invalid argument) # ./perf record -q -e raw_syscalls:sys_enter --filter 'comm != perf' -a sleep 5 Error: failed to set filter with 22 (Invalid argument) # ./perf record -q -e raw_syscalls:sys_enter --filter 'common_ppid != '$$ -a sleep 5 Error: failed to set filter with 22 (Invalid argument) This is because comm, ppid, common_ppid, etc, aren't available for those tracepoints. I thought there might be a simple way I'm missing. I'm on linux-3.16-rc2. Thanks, Brendan -- http://www.brendangregg.com -- To unsubscribe from this list: send the line "unsubscribe linux-perf-users" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
