Re: [PATCH v4 4/5] perf stat: Enable iostat mode for x86 platforms
From: liuqi (BA)
Date: Thu Mar 11 2021 - 02:03:41 EST
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@xxxxxxxxxxxxxxx>
---
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>
.