Re: [PATCH V6 13/15] perf intel-pt: Add support for text poke events

From: Jiri Olsa
Date: Tue Apr 21 2020 - 09:06:30 EST


On Tue, Apr 21, 2020 at 04:02:32PM +0300, Adrian Hunter wrote:
> On 21/04/20 3:50 pm, Jiri Olsa wrote:
> > On Sun, Apr 05, 2020 at 11:13:25PM +0300, Adrian Hunter wrote:
> >> Select text poke events when available and the kernel is being traced.
> >> Process text poke events to invalidate entries in Intel PT's instruction
> >> cache.
> >>
> >> Example:
> >>
> >> The example requires kernel config:
> >> CONFIG_PROC_SYSCTL=y
> >> CONFIG_SCHED_DEBUG=y
> >> CONFIG_SCHEDSTATS=y
> >>
> >> Before:
> >>
> >> # perf record -o perf.data.before --kcore -a -e intel_pt//k -m,64M &
> >> # cat /proc/sys/kernel/sched_schedstats
> >> 0
> >> # echo 1 > /proc/sys/kernel/sched_schedstats
> >> # cat /proc/sys/kernel/sched_schedstats
> >> 1
> >> # echo 0 > /proc/sys/kernel/sched_schedstats
> >> # cat /proc/sys/kernel/sched_schedstats
> >> 0
> >> # kill %1
> >> [ perf record: Woken up 1 times to write data ]
> >> [ perf record: Captured and wrote 3.341 MB perf.data.before ]
> >> [1]+ Terminated perf record -o perf.data.before --kcore -a -e intel_pt//k -m,64M
> >> # perf script -i perf.data.before --itrace=e >/dev/null
> >> Warning:
> >> 474 instruction trace errors
> >>
> >> After:
> >>
> >> # perf record -o perf.data.after --kcore -a -e intel_pt//k -m,64M &
> >> # cat /proc/sys/kernel/sched_schedstats
> >> 0
> >> # echo 1 > /proc/sys/kernel/sched_schedstats
> >> # cat /proc/sys/kernel/sched_schedstats
> >> 1
> >> # echo 0 > /proc/sys/kernel/sched_schedstats
> >> # cat /proc/sys/kernel/sched_schedstats
> >> 0
> >> # kill %1
> >> [ perf record: Woken up 1 times to write data ]
> >> [ perf record: Captured and wrote 2.646 MB perf.data.after ]
> >> [1]+ Terminated perf record -o perf.data.after --kcore -a -e intel_pt//k -m,64M
> >> # perf script -i perf.data.after --itrace=e >/dev/null
> >
> >
> > I'm still seeing some, probably I'm missing some CONFIG, will check
> >
> > # ./perf record -o perf.data.after --kcore -a -e intel_pt//k -m,64M &
> > [1] 5880
> > # cat /proc/sys/kernel/sched_schedstats
> > 0
> > # echo 1 > /proc/sys/kernel/sched_schedstats
> > # cat /proc/sys/kernel/sched_schedstats
> > 1
> > # echo 0 > /proc/sys/kernel/sched_schedstats
> > # kill %1
> > # [ perf record: Woken up 1 times to write data ]
> > [ perf record: Captured and wrote 6.181 MB perf.data.after ]
> > [1]+ Terminated ./perf record -o perf.data.after --kcore -a -e intel_pt//k -m,64M
> > # ./perf script --itrace=e -i perf.data.after > /dev/null
> > Warning:
> > 18837 instruction trace errors
> >
> > # ./perf script --itrace=e -i perf.data.after | head
> > instruction trace error type 1 time 9274.420582345 cpu 9 pid 845 tid 845 ip 0xffffffff814e6cf2 code 6: Trace doesn't match instruction
> > instruction trace error type 1 time 9274.422229726 cpu 39 pid 5880 tid 5880 ip 0xffffffffa030a320 code 6: Trace doesn't match instruction
> > instruction trace error type 1 time 9274.422231972 cpu 39 pid 5880 tid 5880 ip 0xffffffffa0315c1c code 6: Trace doesn't match instruction
> > instruction trace error type 1 time 9274.422236141 cpu 39 pid 5880 tid 5880 ip 0xffffffff81143263 code 6: Trace doesn't match instruction
> > instruction trace error type 1 time 9274.422237424 cpu 39 pid 5880 tid 5880 ip 0xffffffff8115c388 code 6: Trace doesn't match instruction
> > instruction trace error type 1 time 9274.422239028 cpu 39 pid 5880 tid 5880 ip 0xffffffff811428c9 code 6: Trace doesn't match instruction
> > instruction trace error type 1 time 9274.422239028 cpu 39 pid 5880 tid 5880 ip 0xffffffffa13279fb code 5: Failed to get instruction
> > instruction trace error type 1 time 9274.422242556 cpu 39 pid 5880 tid 5880 ip 0xffffffff814e9c73 code 6: Trace doesn't match instruction
> > instruction trace error type 1 time 9274.422258915 cpu 39 pid 5880 tid 5880 ip 0xffffffff810d7da2 code 6: Trace doesn't match instruction
> > instruction trace error type 1 time 9274.422258915 cpu 39 pid 5880 tid 5880 ip 0xffffffffa030a0b2 code 6: Trace doesn't match instruction
>
> I don't think it can be CONFIG. Can you share the branch you are using?
> Then I can test it.
>

I built the one you mentioned in cover email:
git://git.infradead.org/users/ahunter/linux-perf.git text_poke

jirka