Re: [PATCH v2 5/6] perf stat: Enable iiostat mode for x86 platforms
From: Alexander Antonov
Date: Wed Jan 13 2021 - 07:10:08 EST
On 1/6/2021 12:02 PM, Namhyung Kim wrote:
On Wed, Dec 23, 2020 at 10:03 PM Alexander Antonov
<alexander.antonov@xxxxxxxxxxxxxxx> 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
IIO stack:
- Inbound Read: I/O devices below IIO stack read from the host memory
- Inbound Write: I/O devices below IIO stack write to the host memory
- Outbound Read: CPU reads from I/O devices below IIO stack
- Outbound Write: CPU writes to I/O devices below IIO stack
Each metric requiries only one IIO event which increments at every 4B
transfer in corresponding direction. The formulas to compute metrics
are generic:
#EventCount * 4B / (1024 * 1024)
Hmm.. maybe we can do this with JSON metrics, no?
Do you mean to add metrics to *-metrics.json file?
Looks like it's possible but in this case JSON file should be updated
for each
new enabled platform and calculations will be the same.
I would prefer to leave it as is because perf will work without changing of
userspace part once IIO sysfs attributes are added for new platforms.
Signed-off-by: Alexander Antonov <alexander.antonov@xxxxxxxxxxxxxxx>
---
tools/perf/Documentation/perf-iiostat.txt | 89 ++++++
tools/perf/Makefile.perf | 5 +-
tools/perf/arch/x86/util/Build | 1 +
tools/perf/arch/x86/util/iiostat.c | 337 ++++++++++++++++++++++
tools/perf/command-list.txt | 1 +
tools/perf/perf-iiostat.sh | 12 +
6 files changed, 444 insertions(+), 1 deletion(-)
create mode 100644 tools/perf/Documentation/perf-iiostat.txt
create mode 100644 tools/perf/perf-iiostat.sh
diff --git a/tools/perf/Documentation/perf-iiostat.txt b/tools/perf/Documentation/perf-iiostat.txt
new file mode 100644
index 000000000000..38b5697b0d85
--- /dev/null
+++ b/tools/perf/Documentation/perf-iiostat.txt
@@ -0,0 +1,89 @@
+perf-iiostat(1)
+===============
+
+NAME
+----
+perf-iiostat - Show I/O performance metrics
+
+SYNOPSIS
+--------
+[verse]
+'perf iiostat' show
+'perf iiostat' <ports> -- <command> [<options>]
+
+DESCRIPTION
+-----------
+Mode is intended to provide four I/O performance metrics per each IIO
+stack (PCIe root port):
+
+- Inbound Read - I/O devices below IIO stack read from the host memory, in MB
+
+- Inbound Write - I/O devices below IIO stack write to the host memory, in MB
+
+- Outbound Read - CPU reads from I/O devices below IIO stack, in MB
+
+- Outbound Write - CPU writes to I/O devices below IIO stack, in MB
+
+OPTIONS
+-------
+<command>...::
+ Any command you can specify in a shell.
+
+show::
+ List all IIO stacks.
I'd prefer 'list' for this, but not a strong opinion..
The 'list' is fine for me as well.
+
+<ports>::
+ Select the root ports for monitoring. Comma-separated list is supported.
+
+EXAMPLES
+--------
+
+1. List all IIO stacks (example for 2-S platform):
+
+ $ perf iiostat show
+ 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>
+
+2. Collect metrics for all I/O stacks:
+
+ $ perf iiostat -- dd if=/dev/zero of=/dev/nvme0n1 bs=1M oflag=direct
+ 357708+0 records in
+ 357707+0 records out
+ 375083606016 bytes (375 GB, 349 GiB) copied, 215.974 s, 1.7 GB/s
+
+ Performance counter stats for 'system wide':
+
+ port Inbound Read(MB) Inbound Write(MB) Outbound Read(MB) Outbound Write(MB)
+ 0000:00 1 0 2 3
+ 0000:80 0 0 0 0
+ 0000:17 352552 43 0 21
+ 0000:85 0 0 0 0
+ 0000:3a 3 0 0 0
+ 0000:ae 0 0 0 0
+ 0000:5d 0 0 0 0
+ 0000:d7 0 0 0 0
+
+3. Collect metrics for comma-separated list of I/O stacks:
+
+ $ perf iiostat 0000:17,0:3a -- dd if=/dev/zero of=/dev/nvme0n1 bs=1M oflag=direct
+ 357708+0 records in
+ 357707+0 records out
+ 375083606016 bytes (375 GB, 349 GiB) copied, 197.08 s, 1.9 GB/s
+
+ Performance counter stats for 'system wide':
+
+ port Inbound Read(MB) Inbound Write(MB) Outbound Read(MB) Outbound Write(MB)
+ 0000:17 358559 44 0 22
+ 0000:3a 3 2 0 0
+
+ 197.081983474 seconds time elapsed
+
+SEE ALSO
+--------
+linkperf:perf-stat[1]
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[SNIP]
diff --git a/tools/perf/perf-iiostat.sh b/tools/perf/perf-iiostat.sh
new file mode 100644
index 000000000000..2c5168d2550b
--- /dev/null
+++ b/tools/perf/perf-iiostat.sh
@@ -0,0 +1,12 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+# perf iiostat
+# Alexander Antonov <alexander.antonov@xxxxxxxxxxxxxxx>
+
+if [[ "$1" == "show" ]] || [[ "$1" =~ ([a-f0-9A-F]{1,}):([a-f0-9A-F]{1,2})(,)? ]]; then
+ DELIMITER="="
+else
+ DELIMITER=" "
+fi
+
+perf stat --iiostat$DELIMITER$*
Why is this needed?
Thanks,
Namhyung
Arnaldo raised question relates to format of 'perf stat --iiostat'
subcommand
and explained how it can be changed to 'perf iiostat' through the aliases
mechanism in perf.
Thank you,
Alexander
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