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

From: Xin Long
Date: Tue Nov 06 2018 - 03:22:29 EST


On Mon, Nov 5, 2018 at 5:49 PM Jiri Olsa <jolsa@xxxxxxxxxx> wrote:
>
> On Mon, Nov 05, 2018 at 03:20:15PM +0900, Xin Long wrote:
>
> SNIP
>
> > > > > [root@ibm-x3650m4-02 perf]# ./perf probe 'consume_skb'
> > > > > [root@ibm-x3650m4-02 perf]# ./perf record -g -e probe:consume_skb* -aR ^C
> > > > >
> > > > Thanks Jiri,
> > > >
> > > > My debugging script is using tracepoint with some filters which I
> > > > don't think probe can support.
> > > > Any one have fixes for this tracepoint issue?
> > >
> > > trying to bisect that.. looks like orc code issue,
> > > it works for me when you switch to fp unwind:
> > > CONFIG_UNWINDER_FRAME_POINTER
> > >
> >
> > That's a good workaround, thanks.
> >
> > Another problem is when I'm using perf built manually from upstream kernel tree,
> > I couldn't see the function's names.
> > # perf --version
> > perf version 4.19.g26f1de
> >
> > # perf report -T
> > # To display the perf.data header info, please use
> > --header/--header-only options.
> > #
> > #
> > # Total Lost Samples: 0
> > #
> > # Samples: 97 of event 'probe:consume_skb'
> > # Event count (approx.): 97
> > #
> > # Children Self Trace output
> > # ........ ........ ..................
> > #
> > 100.00% 100.00% (ffffffff86f090f0)
> > |
> > |--93.81%--0xffffffff868000e6
> > | 0xffffffff8684ed7f
> > | 0xffffffff868e97ad
> > | 0xffffffff868e953a
> > | 0xffffffff87087623
> > | 0xffffffff8682a06f
> > | 0xffffffff870872ad
> > | |
> > | |--89.69%--0xffffffff8720098f
> > | | 0xffffffff87201b69
> > | | 0xffffffff868b9c2e
> >
> >
> > The below is with rhel7's perf
> > # perf --version
> > perf version 3.10.0-957.el7.x86_64.debug
> > # perf report -T
> > # To display the perf.data header info, please use
> > --header/--header-only options.
> > #
> > #
> > # Total Lost Samples: 0
> > #
> > # Samples: 97 of event 'probe:consume_skb'
> > # Event count (approx.): 97
> > #
> > # Children Self Trace output
> > # ........ ........ ..................
> > #
> > 100.00% 100.00% (ffffffff86f090f0)
> > |
> > |--93.81%--0x2000e6
> > | start_secondary
> > | cpu_startup_entry
> > | do_idle
> > | default_idle_call
> > | arch_cpu_idle
> > | default_idle
> > | |
> > | |--89.69%--ret_from_intr
> > | | do_IRQ
> > | | irq_exit
>
> I think that's already fixed on Arnaldo's perf/urgent branch,
> git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux.git
>
> but perhaps this post as well:
> https://lore.kernel.org/lkml/20181031091043.23465-1-adrian.hunter@xxxxxxxxx/
>
> please give it a try.. it should be merged in soon
I will try it later, I have another question?
# perf report -T

# Samples: 97 of event 'probe:consume_skb'
# Event count (approx.): 97
#
# Children Self Trace output
# ........ ........ ..................
#
100.00% 100.00% (ffffffff86f090f0)
|
|--93.81%--0x2000e6
| start_secondary
| cpu_startup_entry
| do_idle
| default_idle_call
| arch_cpu_idle
[...]
| | |
| | --2.06%--arp_process
| | neigh_update
| | __neigh_notify
| | rtnl_notify
| | nlmsg_notify
| | consume_skb <-----[1]


This command can show a nice tree, and it has the total samples number 97.
But I couldn't see how many of them are from [1]?
Do you know how to count each path's numbers?
Is there an option for "perf report" to do these statistics?
Thanks.