v2: https://lkml.org/lkml/2020/7/17/369
Changelog v2-->v3
Based on comments from Gautham R. Shenoy adding the following in the
selftest,
1. Grepping modules to determine if already loaded
2. Wrapper to enable/disable states
3. Preventing any operation/test on offlined CPUs
---
The patch series introduces a mechanism to measure wakeup latency for
IPI and timer based interrupts
The motivation behind this series is to find significant deviations
behind advertised latency and resisdency values
To achieve this, we introduce a kernel module and expose its control
knobs through the debugfs interface that the selftests can engage with.
The kernel module provides the following interfaces within
/sys/kernel/debug/latency_test/ for,
1. IPI test:
ipi_cpu_dest # Destination CPU for the IPI
ipi_cpu_src # Origin of the IPI
ipi_latency_ns # Measured latency time in ns
2. Timeout test:
timeout_cpu_src # CPU on which the timer to be queued
timeout_expected_ns # Timer duration
timeout_diff_ns # Difference of actual duration vs expected timer
To include the module, check option and include as module
kernel hacking -> Cpuidle latency selftests
The selftest inserts the module, disables all the idle states and
enables them one by one testing the following:
1. Keeping source CPU constant, iterates through all the CPUS measuring
IPI latency for baseline (CPU is busy with
"cat /dev/random > /dev/null" workload) and the when the CPU is
allowed to be at rest
2. Iterating through all the CPUs, sending expected timer durations to
be equivalent to the residency of the the deepest idle state
enabled and extracting the difference in time between the time of
wakeup and the expected timer duration
Usage
-----
Can be used in conjuction to the rest of the selftests.
Default Output location in: tools/testing/cpuidle/cpuidle.log
To run this test specifically:
$ make -C tools/testing/selftests TARGETS="cpuidle" run_tests
There are a few optinal arguments too that the script can take
[-h <help>]
[-m <location of the module>]
[-o <location of the output>]
Sample output snippet
---------------------
--IPI Latency Test---
--Baseline IPI Latency measurement: CPU Busy--
SRC_CPU DEST_CPU IPI_Latency(ns)
...
0 8 1996
0 9 2125
0 10 1264
0 11 1788
0 12 2045
Baseline Average IPI latency(ns): 1843
---Enabling state: 5---
SRC_CPU DEST_CPU IPI_Latency(ns)
0 8 621719
0 9 624752
0 10 622218
0 11 623968
0 12 621303
Expected IPI latency(ns): 100000
Observed Average IPI latency(ns): 622792
--Timeout Latency Test--
--Baseline Timeout Latency measurement: CPU Busy--
Wakeup_src Baseline_delay(ns)
...
8 2249
9 2226
10 2211
11 2183
12 2263
Baseline Average timeout diff(ns): 2226
---Enabling state: 5---
8 10749
9 10911
10 10912
11 12100
12 73276
Expected timeout(ns): 10000200
Observed Average timeout diff(ns): 23589
Pratik Rajesh Sampat (2):
cpuidle: Trace IPI based and timer based wakeup latency from idle
states
selftest/cpuidle: Add support for cpuidle latency measurement
drivers/cpuidle/Makefile | 1 +
drivers/cpuidle/test-cpuidle_latency.c | 150 ++++++++++
lib/Kconfig.debug | 10 +
tools/testing/selftests/Makefile | 1 +
tools/testing/selftests/cpuidle/Makefile | 6 +
tools/testing/selftests/cpuidle/cpuidle.sh | 310 +++++++++++++++++++++
tools/testing/selftests/cpuidle/settings | 1 +
7 files changed, 479 insertions(+)
create mode 100644 drivers/cpuidle/test-cpuidle_latency.c
create mode 100644 tools/testing/selftests/cpuidle/Makefile
create mode 100755 tools/testing/selftests/cpuidle/cpuidle.sh
create mode 100644 tools/testing/selftests/cpuidle/settings
--
2.25.4
Hi Brendan:
When I run kunit test in um , it failed on kernel 5.8-rc* while
succeeded in v5.7 with same configuration. is this a bug?
Here is my operation:
gcc version 7.5.0 (Ubuntu 7.5.0-3ubuntu1~18.04)
the kunitconfig:
Cixi.Geng:~/git-projects/torvals-linux$ cat .kunitconfig
CONFIG_KUNIT=y
CONFIG_KUNIT_TEST=y
CONFIG_KUNIT_EXAMPLE_TEST=y
command:
Cixi.Geng:~/git-projects/torvals-linux$ ./tools/testing/kunit/kunit.py run
the Error log:
[17:51:14] Configuring KUnit Kernel ...
[17:51:14] Building KUnit Kernel ...
ERROR:root:b"make[1]:
\xe8\xbf\x9b\xe5\x85\xa5\xe7\x9b\xae\xe5\xbd\x95\xe2\x80\x9c/home/cixi.geng1/git-projects/torvals-linux/.kunit\xe2\x80\x9d\n/home/cixi.geng1/git-projects/torvals-linux/Makefile:551:
recipe for target 'outputmakefile' failed\nmake[1]:
\xe7\xa6\xbb\xe5\xbc\x80\xe7\x9b\xae\xe5\xbd\x95\xe2\x80\x9c/home/cixi.geng1/git-projects/torvals-linux/.kunit\xe2\x80\x9d\nMakefile:185:
recipe for target '__sub-make' failed\n"
From: Paolo Pisati <paolo.pisati(a)canonical.com>
[ Upstream commit 651149f60376758a4759f761767965040f9e4464 ]
During setup():
...
for ns in h0 r1 h1 h2 h3
do
create_ns ${ns}
done
...
while in cleanup():
...
for n in h1 r1 h2 h3 h4
do
ip netns del ${n} 2>/dev/null
done
...
and after removing the stderr redirection in cleanup():
$ sudo ./fib_nexthop_multiprefix.sh
...
TEST: IPv4: host 0 to host 3, mtu 1400 [ OK ]
TEST: IPv6: host 0 to host 3, mtu 1400 [ OK ]
Cannot remove namespace file "/run/netns/h4": No such file or directory
$ echo $?
1
and a non-zero return code, make kselftests fail (even if the test
itself is fine):
...
not ok 34 selftests: net: fib_nexthop_multiprefix.sh # exit=1
...
Signed-off-by: Paolo Pisati <paolo.pisati(a)canonical.com>
Reviewed-by: David Ahern <dsahern(a)gmail.com>
Signed-off-by: David S. Miller <davem(a)davemloft.net>
Signed-off-by: Sasha Levin <sashal(a)kernel.org>
---
tools/testing/selftests/net/fib_nexthop_multiprefix.sh | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/testing/selftests/net/fib_nexthop_multiprefix.sh b/tools/testing/selftests/net/fib_nexthop_multiprefix.sh
index 9dc35a16e4159..51df5e305855a 100755
--- a/tools/testing/selftests/net/fib_nexthop_multiprefix.sh
+++ b/tools/testing/selftests/net/fib_nexthop_multiprefix.sh
@@ -144,7 +144,7 @@ setup()
cleanup()
{
- for n in h1 r1 h2 h3 h4
+ for n in h0 r1 h1 h2 h3
do
ip netns del ${n} 2>/dev/null
done
--
2.25.1
From: Paolo Pisati <paolo.pisati(a)canonical.com>
[ Upstream commit b346c0c85892cb8c53e8715734f71ba5bbec3387 ]
According to 'man 8 ip-netns', if `ip netns identify` returns an empty string,
there's no net namespace associated with current PID: fix the net ns entrance
logic.
Signed-off-by: Paolo Pisati <paolo.pisati(a)canonical.com>
Acked-by: Willem de Bruijn <willemb(a)google.com>
Signed-off-by: David S. Miller <davem(a)davemloft.net>
Signed-off-by: Sasha Levin <sashal(a)kernel.org>
---
tools/testing/selftests/net/txtimestamp.sh | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/testing/selftests/net/txtimestamp.sh b/tools/testing/selftests/net/txtimestamp.sh
index eea6f5193693f..31637769f59f6 100755
--- a/tools/testing/selftests/net/txtimestamp.sh
+++ b/tools/testing/selftests/net/txtimestamp.sh
@@ -75,7 +75,7 @@ main() {
fi
}
-if [[ "$(ip netns identify)" == "root" ]]; then
+if [[ -z "$(ip netns identify)" ]]; then
./in_netns.sh $0 $@
else
main $@
--
2.25.1
From: Paolo Pisati <paolo.pisati(a)canonical.com>
[ Upstream commit 651149f60376758a4759f761767965040f9e4464 ]
During setup():
...
for ns in h0 r1 h1 h2 h3
do
create_ns ${ns}
done
...
while in cleanup():
...
for n in h1 r1 h2 h3 h4
do
ip netns del ${n} 2>/dev/null
done
...
and after removing the stderr redirection in cleanup():
$ sudo ./fib_nexthop_multiprefix.sh
...
TEST: IPv4: host 0 to host 3, mtu 1400 [ OK ]
TEST: IPv6: host 0 to host 3, mtu 1400 [ OK ]
Cannot remove namespace file "/run/netns/h4": No such file or directory
$ echo $?
1
and a non-zero return code, make kselftests fail (even if the test
itself is fine):
...
not ok 34 selftests: net: fib_nexthop_multiprefix.sh # exit=1
...
Signed-off-by: Paolo Pisati <paolo.pisati(a)canonical.com>
Reviewed-by: David Ahern <dsahern(a)gmail.com>
Signed-off-by: David S. Miller <davem(a)davemloft.net>
Signed-off-by: Sasha Levin <sashal(a)kernel.org>
---
tools/testing/selftests/net/fib_nexthop_multiprefix.sh | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/testing/selftests/net/fib_nexthop_multiprefix.sh b/tools/testing/selftests/net/fib_nexthop_multiprefix.sh
index 9dc35a16e4159..51df5e305855a 100755
--- a/tools/testing/selftests/net/fib_nexthop_multiprefix.sh
+++ b/tools/testing/selftests/net/fib_nexthop_multiprefix.sh
@@ -144,7 +144,7 @@ setup()
cleanup()
{
- for n in h1 r1 h2 h3 h4
+ for n in h0 r1 h1 h2 h3
do
ip netns del ${n} 2>/dev/null
done
--
2.25.1