Re: [PATCH v4 4/5] perf stat: Enable iostat mode for x86 platforms

["liuqi (BA)" <liuqi115@huawei.com>]

On 2021/3/11 0:19, Alexander Antonov wrote:
> 
> On 3/9/2021 10:51 AM, liuqi (BA) wrote:
>> Hi Alexander,
>>
>> On 2021/2/3 21:58, Alexander Antonov wrote:
>>> This functionality is based on recently introduced sysfs attributes
>>> for Intel® Xeon® Scalable processor family (code name Skylake-SP):
>>> Commit bb42b3d39781 ("perf/x86/intel/uncore: Expose an Uncore unit to
>>> IIO PMON mapping")
>>>
>>> Mode is intended to provide four I/O performance metrics in MB per each
>>> PCIe root port:
>>>   - Inbound Read: I/O devices below root port read from the host memory
>>>   - Inbound Write: I/O devices below root port write to the host memory
>>>   - Outbound Read: CPU reads from I/O devices below root port
>>>   - Outbound Write: CPU writes to I/O devices below root port
>>>
>>> Each metric requiries only one uncore event which increments at every 4B
>>> transfer in corresponding direction. The formulas to compute metrics
>>> are generic:
>>>      #EventCount * 4B / (1024 * 1024)
>>>
>>> Signed-off-by: Alexander Antonov<alexander.antonov@linux.intel.com>
>>> ---
>>>   tools/perf/Documentation/perf-iostat.txt |  88 ++++++
>>>   tools/perf/Makefile.perf                 |   5 +-
>>>   tools/perf/arch/x86/util/Build           |   1 +
>>>   tools/perf/arch/x86/util/iostat.c        | 345 +++++++++++++++++++++++
>>>   tools/perf/command-list.txt              |   1 +
>>>   tools/perf/perf-iostat.sh                |  12 +
>>>   6 files changed, 451 insertions(+), 1 deletion(-)
>>>   create mode 100644 tools/perf/Documentation/perf-iostat.txt
>>>   create mode 100644 tools/perf/perf-iostat.sh
>>>
>>> diff --git a/tools/perf/Documentation/perf-iostat.txt 
>>> b/tools/perf/Documentation/perf-iostat.txt
>>> new file mode 100644
>>> index 000000000000..165176944031
>>> --- /dev/null
>>> +++ b/tools/perf/Documentation/perf-iostat.txt
>>> @@ -0,0 +1,88 @@
>>> +perf-iostat(1)
>>> +===============
>>> +
>>> +NAME
>>> +----
>>> +perf-iostat - Show I/O performance metrics
>>> +
>>> +SYNOPSIS
>>> +--------
>>> +[verse]
>>> +'perf iostat' list
>>> +'perf iostat' <ports> -- <command> [<options>]
>>> +
>>> +DESCRIPTION
>>> +-----------
>>> +Mode is intended to provide four I/O performance metrics per each 
>>> PCIe root port:
>>> +
>>> +- Inbound Read   - I/O devices below root port read from the host 
>>> memory, in MB
>>> +
>>> +- Inbound Write  - I/O devices below root port write to the host 
>>> memory, in MB
>>> +
>>> +- Outbound Read  - CPU reads from I/O devices below root port, in MB
>>> +
>>> +- Outbound Write - CPU writes to I/O devices below root port, in MB
>>> +
>>> +OPTIONS
>>> +-------
>>> +<command>...::
>>> +    Any command you can specify in a shell.
>>> +
>>> +list::
>>> +    List all PCIe root ports.
>>
>> I noticed that "iostat" commond and cmd_iostat() callback function is 
>> not registered in cmd_struct in perf.c. So I think "perf iostat list" 
>> perhaps can not work properly.
>>
>> I also test this patchset on x86 platform, and here is the log:
>>
>> root@ubuntu:/home/lq# ./perf iostat list
>> perf: 'iostat' is not a perf-command. See 'perf --help'.
>> root@ubuntu:/home/lq# ./perf stat --iostat
>> ^C
>>  Performance counter stats for 'system wide':
>>
>>    port             Inbound Read(MB)    Inbound Write(MB) Outbound 
>> Read(MB)   Outbound Write(MB)
>> 0000:00                    0 0                    0                  0
>> 0000:80                    0 0                    0                  0
>> 0000:17                    0 0                    0                  0
>> 0000:85                    0 0                    0                  0
>> 0000:3a                    0 0                    0                  0
>> 0000:ae                    0 0                    0                  0
>> 0000:5d                    0 0                    0                  0
>> 0000:d7                    0 0                    0                  0
>>
>>        0.611303832 seconds time elapsed
>>
>>
>> root@ubuntu:/home/lq# ./perf stat --iostat=0000:17
>> ^C
>>  Performance counter stats for 'system wide':
>>
>>    port             Inbound Read(MB)    Inbound Write(MB) Outbound 
>> Read(MB)   Outbound Write(MB)
>> 0000:17                    0 0                    0                  0
>>
>>        0.521317572 seconds time elapsed
>>
>> So how does following perf iostat list work, did I miss something?
>>
>> Thanks,
>> Qi
>>
> Hello,
> 
> The 'iostat' mode uses aliases mechanism in perf same as 'perf archive' and
> in this case you don't need to add function callback into cmd_struct.
> For example, the command 'perf iostat list' will be converted to
> 'perf stat --iostat=list'.
> 
> After building the perf tool you should have two shell scripts in 
> tools/perf
> directory and one of them is executable, for example:
> # make -C tools/perf
> # ls -l tools/perf/perf-iostat*
> -rwxr-xr-x 1 root root 290 Mar 10 18:17 perf-iostat
> -rw-r--r-- 1 root root 290 Feb  3 15:14 perf-iostat.sh
> 
> It should be possible to run 'perf iostat' from build directory:
> # cd tools/perf
> # ./perf iostat list
> S0-uncore_iio_0<0000:00>
> S1-uncore_iio_0<0000:80>
> S0-uncore_iio_1<0000:17>
> S1-uncore_iio_1<0000:85>
> S0-uncore_iio_2<0000:3a>
> S1-uncore_iio_2<0000:ae>
> S0-uncore_iio_3<0000:5d>
> S1-uncore_iio_3<0000:d7>
> 
> Also you can copy 'perf-iostat' to ~/libexec/perf-core/ or just run 
> 'make install'
> 
> # make install
> # cp perf /usr/bin/
> # ls -lh ~/libexec/perf-core/
> total 24K
> -rwxr-xr-x 1 root root 1.4K Mar 10 18:17 perf-archive
> -rwxr-xr-x 1 root root  290 Mar 10 18:17 perf-iostat
> -rwxr-xr-x 1 root root 6.3K Mar 10 18:17 perf-with-kcore
> drwxr-xr-x 4 root root 4.0K Nov  5  2019 scripts
> drwxr-xr-x 4 root root 4.0K Mar 10 18:17 tests
> # perf iostat 0000:17 -I 1000 --interval-count 2
> #           time    port             Inbound Read(MB)    Inbound 
> Write(MB)    Outbound Read(MB)   Outbound Write(MB)
>       1.000220341 0000:17                    0 0 0                    0
>       2.000569569 0000:17                    0 0 0                    0
> 
> Actually, Arnaldo has explained before how does aliases mechanism work.
> 
> I hope it will solve your issue. Otherwise, please email.
> 
> Thank you,
> Alexander

Hi Alexander,

I try it again on x86 platform and it works, thanks a lot:)

Thanks,
Qi
>>> +
>>> +<ports>::
>>> +    Select the root ports for monitoring. Comma-separated list is 
>>> supported.
>>> +
>>> +EXAMPLES
>>> +--------
>>> +
>>> +1. List all PCIe root ports (example for 2-S platform):
>>> +
>>> +   $ perf iostat list
>>> +   S0-uncore_iio_0<0000:00>
>>> +   S1-uncore_iio_0<0000:80>
>>> +   S0-uncore_iio_1<0000:17>
>>> +   S1-uncore_iio_1<0000:85>
>>> +   S0-uncore_iio_2<0000:3a>
>>> +   S1-uncore_iio_2<0000:ae>
>>> +   S0-uncore_iio_3<0000:5d>
>>> +   S1-uncore_iio_3<0000:d7>
>>
> 
> .