linux-kernel - Re: Intel PT not work on 4.5.0-rc

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Date:	Thu, 25 Feb 2016 23:59:46 +0200
From:	Adrian Hunter <adrian.hunter@...el.com>
To:	Arnaldo Carvalho de Melo <acme@...nel.org>
Cc:	Jiri Olsa <jolsa@...nel.org>, Wang Nan <wangnan0@...wei.com>,
	Alexander Shishkin <alexander.shishkin@...ux.intel.com>,
	Ingo Molnar <mingo@...nel.org>,
	David Ahern <dsahern@...il.com>,
	Namhyung Kim <namhyung@...nel.org>,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>
Subject: Re: Intel PT not work on 4.5.0-rc

On 25/02/2016 4:21 p.m., Arnaldo Carvalho de Melo wrote:
> Hi Adrian,
>
> 	While fixing a problem I introducing in parsing 'intel_pt//',
> i.e. the empty '//' part, which is fixed in my perf/core by now, I tried
> using intel_pt with 4.5.0-rc4 and couldn't get any trace :-\
>
> 	Talking with Jiri he tried it on his side, also a Broadwell
> machine, and it worked, same tooling (acme/perf/core) but with a fedora
> kernel, 4.3.5-200.fc22.x86_64.
>
> 	Later I'll try switching to the kernel Jiri is using to see if it works
> for me with that one.
>
> 	I'm busy now and this Broadwell machine is my main workstation,
> can you check if you reproduce this problem?

I am on vacation until some time next week.  I will try to look at
it before then but might not manage it.

>
> [root@...et ~]# perf --version
> perf version 4.5.rc4.gbb109a
> [root@...et ~]# perf record -e intel_pt//u -a sleep 10
> [ perf record: Woken up 1 times to write data ]
> [ perf record: Captured and wrote 1.767 MB perf.data ]
> [root@...et ~]# perf evlist -v
> intel_pt//u: type: 7, size: 112, config: 0x400, { sample_period, sample_freq }: 1, sample_type: IP|TID|TIME|CPU|IDENTIFIER, read_format: ID, disabled: 1, inherit: 1, exclude_kernel: 1, exclude_hv: 1, sample_id_all: 1
> dummy:u: type: 1, size: 112, config: 0x9, { sample_period, sample_freq }: 1, sample_type: IP|TID|TIME|CPU|IDENTIFIER, read_format: ID, disabled: 1, inherit: 1, exclude_kernel: 1, exclude_hv: 1, mmap: 1, comm: 1, task: 1, sample_id_all: 1, mmap2: 1, comm_exec: 1, context_switch: 1
> [root@...et ~]# perf script
> [root@...et ~]#
>
>  From 'perf report -D'
>
> 0x1a8 [0x88]: event: 70
> .
> . ... raw event: size 136 bytes
> .  0000:  46 00 00 00 00 00 88 00 01 00 00 00 00 00 00 00  F...............
> .  0010:  07 00 00 00 00 00 00 00 1f 00 00 00 00 00 00 00  ................
> .  0020:  14 01 58 31 00 00 00 00 69 84 20 d9 d5 3b 00 00  ..X1....i. ..;..
> .  0030:  01 00 00 00 00 00 00 00 00 04 00 00 00 00 00 00  ................
> .  0040:  00 08 00 00 00 00 00 00 03 00 00 00 00 00 00 00  ................
> .  0050:  00 00 00 00 00 00 00 00 01 00 00 00 00 00 00 00  ................
> .  0060:  00 02 00 00 00 00 00 00 00 c0 03 00 00 00 00 00  ................
> .  0070:  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
> .  0080:  02 00 00 00 00 00 00 00                          ........
>
> 0x1a8 [0x88]: PERF_RECORD_AUXTRACE_INFO type: 1
>    PMU Type            7
>    Time Shift          31
>    Time Muliplier      827851028
>    Time Zero           65789656859753
>    Cap Time Zero       1
>    TSC bit             0x400
>    NoRETComp bit       0x800
>    Have sched_switch   3
>    Snapshot mode       0
>    Per-cpu maps        1
>    MTC bit             0x200
>    TSC:CTC numerator   0
>    TSC:CTC denominator 0
>    CYC bit             0x2
>
> [root@...et ~]# perf report -D | tail -13
> Aggregated stats: (excludes AUX area (e.g. instruction trace) decoded / synthesized events)
>             TOTAL events:      21753
>              MMAP events:        130
>              COMM events:        596
>              EXIT events:          2
>              FORK events:        594
>             MMAP2 events:       8541

There ought to be AUX events here, so it looks like no data has been captured,
so a problem with recording.

>      ITRACE_START events:          4
>   SWITCH_CPU_WIDE events:      11882
>    FINISHED_ROUND events:          3
>     AUXTRACE_INFO events:          1
> intel_pt//u stats:
> dummy:u stats:
> [root@...et ~]#
>