On 11/18/2015 02:08 PM, David Ahern wrote: > On 11/18/15 12:01 PM, William Cohen wrote: >> Hi, >> >> I was experimenting with the sched:sched_switch tracepoint to look at >> the time that a process spend off the processor. As a really simple >> experiment record data with: >> >> $ sudo perf record -e sched:sched_switch -- du >> >> Then examine the data with: >> >> $ sudo perf script >> >> The output only shows the sched:sched_switch when the process is moved >> off the processor. However, there is no data showing when the process is >> scheduled back onto the processor: >> >> du 20960 [007] 339893.429394: sched:sched_switch: du:20960 >> [120] R ==> kworker/7:0:16805 [120] >> du 20960 [007] 339893.429411: sched:sched_switch: du:20960 >> [120] R ==> kworker/7:0:16805 [120] >> du 20960 [007] 339893.429544: sched:sched_switch: du:20960 >> [120] R ==> kworker/7:0:16805 [120] >> du 20960 [007] 339893.429556: sched:sched_switch: du:20960 >> [120] R ==> kworker/7:0:16805 [120] >> du 20960 [007] 339893.429561: sched:sched_switch: du:20960 >> [120] R ==> kworker/7:0:16805 [120] >> du 20960 [007] 339893.429567: sched:sched_switch: du:20960 >> [120] R ==> kworker/7:0:16805 [120] >> du 20960 [007] 339893.430150: sched:sched_switch: du:20960 >> [120] R ==> kworker/7:0:16805 [120] >> >> Would it be possible to make perf's process filtering more inclusive so >> that output also includes sched:sched_switch tracepoints for pid that >> are also being scheduled onto the processor? The alternative of >> recording all sched:sched_switch events system-wide and filtering out >> all the unwanted pid's is undesirable. > > Known pain point. I thought Adrian had new sched tracepoints added to handle > it, but I lost track of whether it was accepted. >
Okay, As a workaround can use the filtering to cut down some of data being recorded with: export PID=<process_of_interest> sudo perf record -a -e sched:sched_switch --filter "next_pid == $PID || prev_pid == $PID" -- Is the following the correct thread discussing those new sched tracepoints? https://lkml.org/lkml/2015/6/9/513 -Will -- 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
