Re: perf script doesn't dump a normal call trace

[Jiri Olsa]

On Fri, Nov 02, 2018 at 03:36:13PM +0900, Xin Long wrote:
> On upstream kernel(4.19) or RHEL-8 kernel(4.18.0):
> 
> # perf record -e 'skb:consume_skb' -ag
> ^C[ perf record: Woken up 1 times to write data ]
> [ perf record: Captured and wrote 0.612 MB perf.data (634 samples) ]
> 
> # perf script
> swapper     0 [009] 274370.117711: skb:consume_skb: skbaddr=0xffff962c591d5b00
>         ffffffffa4abe534 consume_skb+0x64 ([kernel.kallsyms])
> 
> kworker/9:1-eve   926 [009] 274370.117729: skb:consume_skb:
> skbaddr=0xffff962c591d5b00
>         ffffffffa4abe534 consume_skb+0x64 ([kernel.kallsyms])
> 
> kworker/9:1-eve   926 [009] 274370.117732: skb:consume_skb:
> skbaddr=0xffff962c591d4900
>         ffffffffa4abe534 consume_skb+0x64 ([kernel.kallsyms])
> 
> swapper     0 [009] 274370.145528: skb:consume_skb: skbaddr=0xffff962c591d4900
>         ffffffffa4abe534 consume_skb+0x64 ([kernel.kallsyms])
> 
> kworker/9:1-eve   926 [009] 274370.145545: skb:consume_skb:
> skbaddr=0xffff962c591d4900
>         ffffffffa4abe534 consume_skb+0x64 ([kernel.kallsyms])
> 
> kworker/9:1-eve   926 [009] 274370.145547: skb:consume_skb:
> skbaddr=0xffff962c591d5b00
>         ffffffffa4abe534 consume_skb+0x64 ([kernel.kallsyms])
> 
> swapper     0 [009] 274370.173443: skb:consume_skb: skbaddr=0xffff962c591d5b00
>         ffffffffa4abe534 consume_skb+0x64 ([kernel.kallsyms])

I can see that on upstream as well, probably something within
tracepoint entry code, because I have it working nicely when
from kprobe, like:

[root@ibm-x3650m4-02 perf]# ./perf probe 'consume_skb'
[root@ibm-x3650m4-02 perf]# ./perf record -g -e probe:consume_skb* -aR ^C

jirka