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

From: Jiri Olsa
Date: Tue Apr 21 2020 - 09:35:57 EST

On Tue, Apr 21, 2020 at 04:10:33PM +0300, Adrian Hunter wrote:

SNIP

> >>> 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
>
> The tools and the kernel?

both from that branch

>
> Does it successfully decode anything? e.g.
> ./perf script --itrace=be -i perf.data.after | head
>

# ./perf script --itrace=be -i perf.data.after | head
perf 5880 [000] 9274.419884: 1 branches:k: 0 [unknown] ([unknown]) => ffffffff8106a4a6 native_write_msr+0x6 (/lib/modules/5.6.0-rc6+/build/vmlinux)
perf 5880 [000] 9274.419884: 1 branches:k: ffffffff8106a4ab native_write_msr+0xb (/lib/modules/5.6.0-rc6+/build/vmlinux) => ffffffff810152f9 pt_config_start+0x59 (/lib/modules/5.6.0-rc6+/build/vmlinux)
perf 5880 [000] 9274.419884: 1 branches:k: ffffffff81015304 pt_config_start+0x64 (/lib/modules/5.6.0-rc6+/build/vmlinux) => ffffffff81015648 pt_event_add+0x38 (/lib/modules/5.6.0-rc6+/build/vmlinux)
perf 5880 [000] 9274.419884: 1 branches:k: ffffffff8101565d pt_event_add+0x4d (/lib/modules/5.6.0-rc6+/build/vmlinux) => ffffffff8121d3ca event_sched_in.isra.0+0xea (/lib/modules/5.6.0-rc6+/build/vmlinux)
perf 5880 [000] 9274.419884: 1 branches:k: ffffffff8121d3dc event_sched_in.isra.0+0xfc (/lib/modules/5.6.0-rc6+/build/vmlinux) => ffffffff8121d3e3 event_sched_in.isra.0+0x103 (/lib/modules/5.6.0-rc6+/build/vmlinux)
perf 5880 [000] 9274.419884: 1 branches:k: ffffffff8121d3f4 event_sched_in.isra.0+0x114 (/lib/modules/5.6.0-rc6+/build/vmlinux) => ffffffff8121d497 event_sched_in.isra.0+0x1b7 (/lib/modules/5.6.0-rc6+/build/vmlinux)
perf 5880 [000] 9274.419884: 1 branches:k: ffffffff8121d4c1 event_sched_in.isra.0+0x1e1 (/lib/modules/5.6.0-rc6+/build/vmlinux) => ffffffff814f9560 __list_add_valid+0x0 (/lib/modules/5.6.0-rc6+/build/vmlinux)
perf 5880 [000] 9274.419884: 1 branches:k: ffffffff814f9593 __list_add_valid+0x33 (/lib/modules/5.6.0-rc6+/build/vmlinux) => ffffffff8121d4c6 event_sched_in.isra.0+0x1e6 (/lib/modules/5.6.0-rc6+/build/vmlinux)
perf 5880 [000] 9274.419884: 1 branches:k: ffffffff8121d4e2 event_sched_in.isra.0+0x202 (/lib/modules/5.6.0-rc6+/build/vmlinux) => ffffffff8121d3fa event_sched_in.isra.0+0x11a (/lib/modules/5.6.0-rc6+/build/vmlinux)
perf 5880 [000] 9274.419884: 1 branches:k: ffffffff8121d401 event_sched_in.isra.0+0x121 (/lib/modules/5.6.0-rc6+/build/vmlinux) => ffffffff8121d40d event_sched_in.isra.0+0x12d (/lib/modules/5.6.0-rc6+/build/vmlinux)

# ./perf script --call-trace -i perf.data.after | head
perf 5880 [000] 9274.419884188: cbr: 8 freq: 798 MHz ( 36%)
perf 5880 [000] 9274.419884389: (/lib/modules/5.6.0-rc6+/build/vmlinux ) __list_add_valid
perf 5880 [000] 9274.419884389: (/lib/modules/5.6.0-rc6+/build/vmlinux ) perf_pmu_enable.part.0
perf 5880 [000] 9274.419884389: (/lib/modules/5.6.0-rc6+/build/vmlinux ) __x86_indirect_thunk_rax
perf 5880 [000] 9274.419884389: (/lib/modules/5.6.0-rc6+/build/vmlinux ) __x86_indirect_thunk_rax
perf 5880 [000] 9274.419884389: (/lib/modules/5.6.0-rc6+/build/vmlinux ) __x86_indirect_thunk_rax
perf 5880 [000] 9274.419884709: (/lib/modules/5.6.0-rc6+/build/vmlinux ) __list_add_valid
perf 5880 [000] 9274.419884709: (/lib/modules/5.6.0-rc6+/build/vmlinux ) rb_next
perf 5880 [000] 9274.419884709: (/lib/modules/5.6.0-rc6+/build/vmlinux ) merge_sched_in
perf 5880 [000] 9274.419884709: (/lib/modules/5.6.0-rc6+/build/vmlinux ) __x86_indirect_thunk_rax

jirka