On Sep 18, 2025 / 16:53, Yu Kuai wrote:
> From: Yu Kuai <yukuai3@xxxxxxxxxx>
>
> While I'm looking at another deadlock issue for blk-throtl, it's found
> during test that lockdep is reporting another issue quite eazy, I'm
> adding regerssion test for now, if anyone is interested. Otherwise, I'll
> go back for this after I finish the problem at hand later.
>
> BTW, maybe we can support to test for scsi_debug instead of null_blk for
> all the throtl tests.
This is a good chance to use blktests' feature to repeat test cases by different
conditions [1]. Test cases can implement set_conditions() hooks for that
purpose.
[1] https://github.com/linux-blktests/blktests/blob/a997ab0ca9b77ddf31b8c632bfe57f7bd75e305e/new#L183
Yu, FYI, I quickly implemented the set_conditions() hooks for the throtl group,
and attach it as a patch. When you have time, please try it out. Each test case
runs twice for null_blk and scsi_debug [2].
- With this patch, the lockdep splat is recreated at throtl/004. It is
observed at throtl/001 also as show in [2].
- throtl/002 fails for scsi_debug. I guess performance difference between
null_blk and scsi_debug is the cause, but not so sure.
- Results are placed in results/nodev_nullb and results/nodev_sdebug.
If you think this approach is good, I will prepare a formal patch series.
[2]
# ./check throtl
throtl/001 (nullb) (basic functionality) [passed]
runtime 4.546s ... 4.753s
throtl/001 (sdebug) (basic functionality) [failed]
runtime 5.386s ... 5.842s
something found in dmesg:
[ 79.444897] [ T1156] run blktests throtl/001 at 2025-09-23 17:05:22
[ 79.684859] [ T1260] sd 9:0:0:0: [sdd] Synchronizing SCSI cache
[ 80.002576] [ T1262] scsi_debug:sdebug_driver_probe: scsi_debug: trim poll_queues to 0. poll_q/nr_hw = (0/1)
[ 80.003950] [ T1262] scsi host9: scsi_debug: version 0191 [20210520]
dev_size_mb=1024, opts=0x0, submit_queues=1, statistics=0
[ 80.009307] [ T1262] scsi 9:0:0:0: Direct-Access Linux scsi_debug 0191 PQ: 0 ANSI: 7
[ 80.011952] [ C2] scsi 9:0:0:0: Power-on or device reset occurred
[ 80.018583] [ T1262] sd 9:0:0:0: Attached scsi generic sg3 type 0
[ 80.020594] [ T103] sd 9:0:0:0: [sdd] 2097152 512-byte logical blocks: (1.07 GB/1.00 GiB)
[ 80.022826] [ T103] sd 9:0:0:0: [sdd] Write Protect is off
...
(See '/home/shin/Blktests/blktests/results/nodev_sdebug/throtl/001.dmesg' for the entire message)
throtl/002 (nullb) (iops limit over IO split) [passed]
runtime 2.586s ... 2.486s
throtl/002 (sdebug) (iops limit over IO split) [failed]
runtime 6.137s ... 6.467s
--- tests/throtl/002.out 2025-09-23 14:05:35.011885439 +0900
+++ /home/shin/Blktests/blktests/results/nodev_sdebug/throtl/002.out.bad 2025-09-23 17:05:37.209794003 +0900
@@ -1,4 +1,4 @@
Running throtl/002
-1
-1
+3
+3
Test complete
throtl/003 (nullb) (bps limit over IO split) [passed]
runtime 2.554s ... 2.424s
throtl/003 (sdebug) (bps limit over IO split) [passed]
runtime 3.075s ... 2.924s
throtl/004 (nullb) (delete disk while IO is throttled) [passed]
runtime 1.269s ... 1.071s
throtl/004 (sdebug) (delete disk while IO is throttled) [passed]
runtime 2.142s ... 1.471s
throtl/005 (nullb) (change config with throttled IO) [passed]
runtime 3.345s ... 3.420s
throtl/005 (sdebug) (change config with throttled IO) [passed]
runtime 3.905s ... 3.984s
throtl/006 (nullb) (test if meta IO has higher priority than data IO) [passed]
runtime 13.014s ... 13.086s
throtl/006 (sdebug) (test if meta IO has higher priority than data IO) [passed]
runtime 5.715s ... 5.631s
throtl/007 (nullb) (bps limit with iops limit over io split) [passed]
runtime 4.527s ... 4.476s
throtl/007 (sdebug) (bps limit with iops limit over io split) [passed]
runtime 5.065s ... 5.043s
From 240a54ea479c156a5fed0f831fa084b138159e7e Mon Sep 17 00:00:00 2001
From: Shin'ichiro Kawasaki <shinichiro.kawasaki@xxxxxxx>
Date: Tue, 23 Sep 2025 15:58:44 +0900
Subject: [PATCH] throtl: introduce THROTL_BLKDEV_TYPES
Currently, the test cases of throtl group run tests for null_blk.
However, it was found that some bugs are not revealed with null_blk. It
is required to run the test cases with scsi_debug to recreate such bugs.
To run the existing test cases for both null_blk and scsi_debug,
introduce the environmental variable THROTL_BLKDEV_TYPES. Its default
value is "nullb sdebug", which indicates to run the test cases for both
null_blk and scsi_debug. When the variable has only "nullb" or "sdebug",
the test cases are run only for null_blk or scsi_debug respectively.
Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@xxxxxxx>
---
Documentation/running-tests.md | 17 ++++++
tests/throtl/001 | 4 ++
tests/throtl/002 | 9 ++-
tests/throtl/003 | 9 ++-
tests/throtl/004 | 10 +++-
tests/throtl/004.out | 3 +-
tests/throtl/005 | 4 ++
tests/throtl/006 | 6 +-
tests/throtl/007 | 9 ++-
tests/throtl/rc | 106 ++++++++++++++++++++++++++++++---
10 files changed, 156 insertions(+), 21 deletions(-)
diff --git a/Documentation/running-tests.md b/Documentation/running-tests.md
index a42fc91..0dc9853 100644
--- a/Documentation/running-tests.md
+++ b/Documentation/running-tests.md
@@ -150,6 +150,23 @@ USE_RXE=1 ./check srp/
'USE_RXE' had the old name 'use_rxe'. The old name is still usable but not
recommended.
+### Blk-throttle tests
+
+The blk-throttle tests has one environment variable below:
+
+- THROTL_BLKDEV_TYPES: 'nullb' 'sdebug'
+ Set up test target block device based on this environment variable value. To
+ test with null_blk, set 'nullb'. To test with scsi_debug, set 'sdebug'.
+ Default value is 'nullb sdebug' which specifies both.
+
+```sh
+To run with null_blk:
+THROTL_BLKDEV_TYPES="nullb" ./check throtl/
+
+To run with scsi_debug:
+THROTL_BLKDEV_TYPES="sdebug" ./check throtl/
+```
+
### Normal user
To run test cases which require normal user privilege, prepare a user and
diff --git a/tests/throtl/001 b/tests/throtl/001
index 835cac2..89a5892 100755
--- a/tests/throtl/001
+++ b/tests/throtl/001
@@ -9,6 +9,10 @@
DESCRIPTION="basic functionality"
QUICK=1
+set_conditions() {
+ _set_throtl_blkdev_type "$@"
+}
+
test() {
echo "Running ${TEST_NAME}"
diff --git a/tests/throtl/002 b/tests/throtl/002
index 02b0969..b082b99 100755
--- a/tests/throtl/002
+++ b/tests/throtl/002
@@ -10,17 +10,20 @@
DESCRIPTION="iops limit over IO split"
QUICK=1
+set_conditions() {
+ _set_throtl_blkdev_type "$@"
+}
+
test() {
echo "Running ${TEST_NAME}"
- local page_size max_secs
+ local page_size
local io_size_kb block_size
local iops=256
page_size=$(getconf PAGE_SIZE)
- max_secs=$((page_size / 512))
- if ! _set_up_throtl max_sectors="${max_secs}"; then
+ if ! _set_up_throtl --sector_size "${page_size}"; then
return 1;
fi
diff --git a/tests/throtl/003 b/tests/throtl/003
index 8276d87..700e9e6 100755
--- a/tests/throtl/003
+++ b/tests/throtl/003
@@ -10,14 +10,17 @@
DESCRIPTION="bps limit over IO split"
QUICK=1
+set_conditions() {
+ _set_throtl_blkdev_type "$@"
+}
+
test() {
echo "Running ${TEST_NAME}"
- local page_size max_secs
+ local page_size
page_size=$(getconf PAGE_SIZE)
- max_secs=$((page_size / 512))
- if ! _set_up_throtl max_sectors="${max_secs}"; then
+ if ! _set_up_throtl --sector_size "${page_size}"; then
return 1;
fi
diff --git a/tests/throtl/004 b/tests/throtl/004
index d1461b9..b1f6110 100755
--- a/tests/throtl/004
+++ b/tests/throtl/004
@@ -11,6 +11,10 @@
DESCRIPTION="delete disk while IO is throttled"
QUICK=1
+set_conditions() {
+ _set_throtl_blkdev_type "$@"
+}
+
test() {
echo "Running ${TEST_NAME}"
@@ -22,13 +26,15 @@ test() {
{
echo "$BASHPID" > "$CGROUP2_DIR/$THROTL_DIR/cgroup.procs"
- _throtl_issue_io write 10M 1
+ _throtl_issue_io write 10M 1 &>> "$FULL"
} &
sleep 0.6
- echo 0 > "/sys/kernel/config/nullb/$THROTL_DEV/power"
+ _delete_throtl_blkdev
wait $!
_clean_up_throtl
+
+ grep --only-matching "Input/output error" "$FULL"
echo "Test complete"
}
diff --git a/tests/throtl/004.out b/tests/throtl/004.out
index e76ec3a..3997531 100644
--- a/tests/throtl/004.out
+++ b/tests/throtl/004.out
@@ -1,4 +1,3 @@
Running throtl/004
-dd: error writing '/dev/dev_nullb': Input/output error
-1
+Input/output error
Test complete
diff --git a/tests/throtl/005 b/tests/throtl/005
index 86e52b3..7691ad1 100755
--- a/tests/throtl/005
+++ b/tests/throtl/005
@@ -10,6 +10,10 @@
DESCRIPTION="change config with throttled IO"
QUICK=1
+set_conditions() {
+ _set_throtl_blkdev_type "$@"
+}
+
test() {
echo "Running ${TEST_NAME}"
diff --git a/tests/throtl/006 b/tests/throtl/006
index b6f47d1..a13092e 100755
--- a/tests/throtl/006
+++ b/tests/throtl/006
@@ -10,6 +10,10 @@
DESCRIPTION="test if meta IO has higher priority than data IO"
QUICK=1
+set_conditions() {
+ _set_throtl_blkdev_type "$@"
+}
+
requires() {
_have_program mkfs.ext4
_have_driver ext4
@@ -34,7 +38,7 @@ test_meta_io() {
test() {
echo "Running ${TEST_NAME}"
- if ! _set_up_throtl memory_backed=1; then
+ if ! _set_up_throtl --memory_backed; then
return 1;
fi
diff --git a/tests/throtl/007 b/tests/throtl/007
index ae59c6f..97dece6 100755
--- a/tests/throtl/007
+++ b/tests/throtl/007
@@ -11,14 +11,17 @@
DESCRIPTION="bps limit with iops limit over io split"
QUICK=1
+set_conditions() {
+ _set_throtl_blkdev_type "$@"
+}
+
test() {
echo "Running ${TEST_NAME}"
- local page_size max_secs
+ local page_size
page_size=$(getconf PAGE_SIZE)
- max_secs=$((page_size / 512))
- if ! _set_up_throtl max_sectors="${max_secs}"; then
+ if ! _set_up_throtl --sector_size "${page_size}"; then
return 1;
fi
diff --git a/tests/throtl/rc b/tests/throtl/rc
index 327084b..1b6453c 100644
--- a/tests/throtl/rc
+++ b/tests/throtl/rc
@@ -6,25 +6,117 @@
. common/rc
. common/null_blk
+. common/scsi_debug
. common/cgroup
THROTL_DIR=$(echo "$TEST_NAME" | tr '/' '_')
-THROTL_DEV=dev_nullb
+THROTL_BLKDEV_TYPES=${THROTL_BLKDEV_TYPES:-"nullb sdebug"}
+throtl_blkdev_type=${throtl_blkdev_type:-"nullb"}
+THROTL_NULL_DEV=dev_nullb
+declare THROTL_DEV
declare THROTL_CLEAR_BASE_SUBTREE_CONTROL_IO
declare THROTL_CLEAR_CGROUP2_DIR_CONTROL_IO
group_requires() {
_have_root
_have_null_blk
+ _have_scsi_debug
_have_kernel_option BLK_DEV_THROTTLING
_have_cgroup2_controller io
_have_program bc
}
+_set_throtl_blkdev_type() {
+ local index=$1
+ local -a types
+
+ read -r -a types <<< "${THROTL_BLKDEV_TYPES[@]}"
+
+ if [[ -z $index ]]; then
+ echo ${#types[@]}
+ return
+ fi
+
+ throtl_blkdev_type=${types[index]}
+ COND_DESC="${throtl_blkdev_type}"
+}
+
+# Prepare null_blk or scsi_debug device to test, based on throtl_blkdev_type.
+_configure_throtl_blkdev() {
+ local sector_size=0 memory_backed=0
+ local -a args
+
+ while [[ $# -gt 0 ]]; do
+ case $1 in
+ --sector_size)
+ sector_size="$2"
+ shift 2
+ ;;
+ --memory_backed)
+ memory_backed=1
+ shift
+ ;;
+ *)
+ echo "WARNING: unknown argument: $1"
+ shift
+ ;;
+ esac
+ done
+
+ THROTL_DEV=
+ case "$throtl_blkdev_type" in
+ nullb)
+ args=("$THROTL_NULL_DEV")
+ ((sector_size)) && args+=(max_sectors="$((sector_size / 512))")
+ ((memory_backed)) && args+=(memory_backed=1)
+ if _configure_null_blk "${args[@]}" power=1; then
+ THROTL_DEV=$THROTL_NULL_DEV
+ return
+ fi
+ ;;
+ sdebug)
+ args=(dev_size_mb=1024)
+ ((sector_size)) && args+=(sector_size="${sector_size}")
+ if _configure_scsi_debug "${args[@]}"; then
+ THROTL_DEV=${SCSI_DEBUG_DEVICES[0]}
+ return
+ fi
+ ;;
+ *)
+ echo "Invalid block device type: ${throtl_blkdev_type}"
+ esac
+ return 1
+}
+
+_delete_throtl_blkdev() {
+ case "$throtl_blkdev_type" in
+ nullb)
+ echo 0 > "/sys/kernel/config/nullb/$THROTL_DEV/power"
+ ;;
+ sdebug)
+ echo 1 > "/sys/block/$THROTL_DEV/device/delete"
+ ;;
+ *)
+ echo "Invalid block device type: ${throtl_blkdev_type}"
+ esac
+}
+
+_exit_throtl_blkdev() {
+ case "$throtl_blkdev_type" in
+ nullb)
+ _exit_null_blk ;;
+ sdebug)
+ _exit_scsi_debug ;;
+ *)
+ echo "Invalid block device type: ${throtl_blkdev_type}"
+ esac
+ unset THROTL_DEV
+}
+
# Create a new null_blk device, and create a new blk-cgroup for test.
_set_up_throtl() {
- if ! _configure_null_blk $THROTL_DEV "$@" power=1; then
+ if ! _configure_throtl_blkdev "$@"; then
return 1
fi
@@ -58,16 +150,16 @@ _clean_up_throtl() {
fi
_exit_cgroup2
- _exit_null_blk
+ _exit_throtl_blkdev
}
_throtl_set_limits() {
- echo "$(cat /sys/block/$THROTL_DEV/dev) $*" > \
+ echo "$(cat /sys/block/"$THROTL_DEV"/dev) $*" > \
"$CGROUP2_DIR/$THROTL_DIR/io.max"
}
_throtl_remove_limits() {
- echo "$(cat /sys/block/$THROTL_DEV/dev) rbps=max wbps=max riops=max wiops=max" > \
+ echo "$(cat /sys/block/"$THROTL_DEV"/dev) rbps=max wbps=max riops=max wiops=max" > \
"$CGROUP2_DIR/$THROTL_DIR/io.max"
}
@@ -102,9 +194,9 @@ _throtl_issue_io() {
start_time=$(date +%s.%N)
if [ "$1" == "read" ]; then
- dd if=/dev/$THROTL_DEV of=/dev/null bs="$2" count="$3" iflag=direct status=none
+ dd if=/dev/"$THROTL_DEV" of=/dev/null bs="$2" count="$3" iflag=direct status=none
elif [ "$1" == "write" ]; then
- dd of=/dev/$THROTL_DEV if=/dev/zero bs="$2" count="$3" oflag=direct status=none
+ dd of=/dev/"$THROTL_DEV" if=/dev/zero bs="$2" count="$3" oflag=direct status=none
fi
end_time=$(date +%s.%N)
--
2.51.0
