RE: [PATCH v5 3/3] Documentation/x86: Documentation for MON group move feature

[Moger, Babu]

[AMD Official Use Only - General]

Hi Peter,

> -----Original Message-----
> From: Peter Newman <peternewman@xxxxxxxxxx>
> Sent: Friday, March 31, 2023 3:12 AM
> To: Moger, Babu <Babu.Moger@xxxxxxx>
> Cc: bp@xxxxxxxxx; dave.hansen@xxxxxxxxxxxxxxx; eranian@xxxxxxxxxx;
> fenghua.yu@xxxxxxxxx; gupasani@xxxxxxxxxx; hpa@xxxxxxxxx;
> james.morse@xxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; mingo@xxxxxxxxxx;
> peternewman@xxxxxxxxxx; reinette.chatre@xxxxxxxxx; skodak@xxxxxxxxxx;
> tglx@xxxxxxxxxxxxx; tony.luck@xxxxxxxxx; x86@xxxxxxxxxx
> Subject: Re: [PATCH v5 3/3] Documentation/x86: Documentation for MON
> group move feature
> 
> Hi Babu,
> 
> On Thu, Mar 30, 2023 at 7:33 PM Moger, Babu <babu.moger@xxxxxxx>
> wrote:
> > On 3/30/23 08:55, Peter Newman wrote:
> > > Describe new support for moving MON groups to a new parent CTRL_MON
> > > group and its restrictions.
> >
> > Sorry for coming in late here. I am planning to test these patches. It
> > would be helpful to give a simple example to test this feature.
> 
> Do you mean inline in the documentation?

Yes. It would be helpful.  I used these simple steps from your script.
# mount  -t resctrl resctrl /sys/fs/resctrl/
# cd /sys/fs/resctrl/
# mkdir _test_c1
# mkdir _test_c2
l# mkdir mon_groups/_test_m1
# echo 1 > mon_groups/_test_m1/cpus
# mkdir _test_c1/mon_groups/_test_c1_m1
l#  echo $$ > _test_c1/tasks
l#  echo $$ > _test_c1/mon_groups/_test_c1_m1/tasks
l#  mv _test_c1/mon_groups/_test_c1_m1/ _test_c2/mon_groups/
# cat info/last_cmd_status
ok
l#  mv mon_groups/_test_m1 _test_c1/mon_groups/
mv: cannot move 'mon_groups/_test_m1' to '_test_c1/mon_groups/_test_m1': Operation not permitted
# cat info/last_cmd_status
Cannot move a MON group that monitors CPUs

> 
> For now, you can also try the patch below. These are the testcases I used.
> 
> I'm planning to convert many of our internal, shell script-based test cases into
> kernel selftests so I can try to upstream them.

Yes. That will be great.
Thanks
Babu


> 
> Thanks!
> -Peter
> 
> 
> ---8<-------
> From f6d215e90db3c416bd39889b9fa1143d798245e0 Mon Sep 17 00:00:00
> 2001
> From: Peter Newman <peternewman@xxxxxxxxxx>
> Date: Tue, 7 Mar 2023 11:57:03 +0100
> Subject: [PATCH] selftests/resctrl: Test for MON group renaming
> 
> Signed-off-by: Peter Newman <peternewman@xxxxxxxxxx>
> ---
>  tools/testing/selftests/resctrl/Makefile      |   2 +
>  .../selftests/resctrl/test_mongrp_move.sh     | 120 ++++++++++++++++++
>  2 files changed, 122 insertions(+)
>  create mode 100755 tools/testing/selftests/resctrl/test_mongrp_move.sh
> 
> diff --git a/tools/testing/selftests/resctrl/Makefile
> b/tools/testing/selftests/resctrl/Makefile
> index 73d53257df42..0b696e7cf19b 100644
> --- a/tools/testing/selftests/resctrl/Makefile
> +++ b/tools/testing/selftests/resctrl/Makefile
> @@ -5,6 +5,8 @@ CFLAGS += $(KHDR_INCLUDES)
> 
>  TEST_GEN_PROGS := resctrl_tests
> 
> +TEST_PROGS := test_mongrp_move.sh
> +
>  include ../lib.mk
> 
>  $(OUTPUT)/resctrl_tests: $(wildcard *.c) diff --git
> a/tools/testing/selftests/resctrl/test_mongrp_move.sh
> b/tools/testing/selftests/resctrl/test_mongrp_move.sh
> new file mode 100755
> index 000000000000..6d9bfc4e0c8d
> --- /dev/null
> +++ b/tools/testing/selftests/resctrl/test_mongrp_move.sh
> @@ -0,0 +1,120 @@
> +#!/bin/sh
> +
> +set -e
> +
> +rc=0
> +
> +cleanup()
> +{
> +	rmdir _test_*
> +	rmdir mon_groups/_test_*
> +}
> +
> +skip_all()
> +{
> +	echo Bail out! $1
> +
> +	cleanup
> +
> +	# SKIP code is 4.
> +	exit 4
> +}
> +
> +expect_success()
> +{
> +	if [ "$1" -eq 0 ]; then
> +		echo ok $2
> +	else
> +		echo not ok $2
> +		rc=1
> +	fi
> +}
> +
> +expect_fail()
> +{
> +	if [ "$1" -eq 0 ]; then
> +		echo not ok $2
> +		rc=1
> +	else
> +		echo ok $2
> +	fi
> +}
> +
> +if [ "$(id -u)" != 0 ]; then
> +	skip_all "must be run as root"
> +fi
> +
> +if [ ! -d /sys/fs/resctrl/info ]; then
> +	mount -t resctrl resctrl /sys/fs/resctrl || skip_all "no resctrlfs"
> +fi
> +
> +cd /sys/fs/resctrl
> +
> +if [ ! -f info/L3_MON/mon_features ]; then
> +	skip_all "no monitoring support"
> +fi
> +
> +if [ ! -f schemata ]; then
> +	skip_all "no allocation support"
> +fi
> +
> +echo "1..11"
> +
> +if [ -d _test_c1 ] || [ -d _test_c2 ] || [ -d mon_groups/_test_m1 ]; then
> +	skip_all "test directories already exist"
> +fi
> +
> +mkdir _test_c1
> +mkdir _test_c2
> +mkdir _test_c3
> +
> +mkdir mon_groups/_test_m1
> +echo 1 > mon_groups/_test_m1/cpus
> +
> +mkdir _test_c1/mon_groups/_test_m1
> +echo $$ > _test_c1/tasks
> +echo $$ > _test_c1/mon_groups/_test_m1/tasks
> +
> +if mv _test_c1/mon_groups/_test_m1 _test_c2/mon_groups; then
> +	echo "ok 1 # MON group move to new parent succeeded"
> +else
> +	echo "1..0 # skip because MON group move to new parent not
> supported"
> +	cleanup
> +	exit 4
> +fi
> +
> +set +e
> +
> +grep -q $$ _test_c2/tasks
> +expect_success $? "2 # PID in new CTRL_MON group"
> +
> +grep -q $$ _test_c2/mon_groups/_test_m1/tasks
> +expect_success $? "3 # PID remains in MON group after move"
> +
> +grep -q $$ _test_c1/tasks
> +expect_fail $? "4 # PID no longer in previous CTRL_MON group"
> +
> +mv _test_c2/mon_groups/_test_m1/cpus mon_groups expect_fail $? "5 #
> +moving files not allowed"
> +
> +mv _test_c2/mon_groups/_test_m1 _test_c2/mon_groups/_test_m2
> +expect_success $? "6 # simple MON directory rename"
> +
> +mv _test_c2/mon_groups/_test_m2 info
> +expect_fail $? "7 # move to info not allowed"
> +
> +mv _test_c2/mon_groups/_test_m2 _test_c2/mon_groups/mon_groups
> +expect_fail $? "8 # rename to mon_groups not allowed"
> +
> +mv mon_groups/_test_m1 _test_c1/mon_groups expect_fail $? "9 # cannot
> +move groups monitoring CPUs"
> +
> +mv mon_groups/_test_m1 mon_groups/_test_m2 expect_success $? "10 #
> +groups monitoring CPUs can be renamed"
> +
> +mv mon_groups/_test_m2/mon_data _test_c1/mon_groups expect_fail $? "11
> +# cannot move subdirectories of a mon_group"
> +
> +cleanup
> +
> +exit $rc
> --
> 2.40.0.423.gd6c402a77b-goog