Messages in this thread | | | From | Vince Weaver <> | Date | Tue, 9 Jun 2015 16:02:15 -0400 (EDT) | Subject | Re: perf/ftrace: does PERF_EVENT_IOC_SET_FILTER serve any purpose? |
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On Tue, 9 Jun 2015, David Ahern wrote:
> On 6/9/15 1:51 PM, Vince Weaver wrote: > > > # perf record -e irq:irq_handler_entry --filter irq==28 -e > > irq:softirq_entry --filter vec==6 -a -- sleep 5 > > invalid or unsupported event: 'irq:irq_handler_entry' > > Run 'perf list' for a list of valid events > > > > perf list doesn't show any tracepoint events, despite having debugfs > > mounted and running as root and /sys/kernel/debug/tracing/events/ being > > populated. > > Do you see this: > > # ls /sys/kernel/debug/tracing/events/irq/irq_handler_entry/ > enable filter format id trigger > > It's used in kernel/irq/handle.c, handle_irq_event_percpu(). As I recall this > tracepoint has been around a long time.
# ls /sys/kernel/debug/tracing/events/irq/irq_handler_entry/ enable filter format id trigger
# perf list .... [ Tracepoints not available: No such file or directory ]
strace shows statfs("/sys/kernel/debug/tracing/events", {f_type=0x74726163, f_bsize=4096, f_blocks=0, f_bfree=0, f_bavail=0, f_files=0, f_ffree=0, f_fsid={0, 0}, f_namelen=255, f_frsize=4096}) = 0
so I have no idea what's going wrong here.
Anyway, on a related question, I see for the event that you use --filter irq==28 How do I find out the valid filters for each event? Do I have to parse the "format" file under /sys/kernel/debug/tracing/events/*/* ?
Vince
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