Re: [LTP] [PATCH 1/1] net: tst_netload_compare(): Ignore performance failures

Petr Vorel
2024-01-02T21:19:32Z

Hi Martin,

> Hi,

> On 19. 12. 23 13:37, Petr Vorel wrote:
> > Performance failures in tests which use tst_netload_compare() (tests in
> > runtest/net.features) can hide a real error (e.g. test fails due missing
> > required kernel module). Best solution would be to have feature tests
> > (likely written in C API) and performance tests (the current ones).

> > But until it happens, just disable performance failure by default,
> > print TINFO message instead unless TST_NET_FEATURES_TEST_PERFORMANCE=1
> > environment variable is set.

> > Signed-off-by: Petr Vorel <pvorel@suse.cz>
> > ---
> > testcases/lib/tst_net.sh | 12 +++++++++---
> > testcases/lib/tst_test.sh | 5 +++--
> > testcases/network/README.md | 4 ++++
> > 3 files changed, 16 insertions(+), 5 deletions(-)

> > diff --git a/testcases/lib/tst_net.sh b/testcases/lib/tst_net.sh
> > index e47ee9676..46d49c266 100644
> > --- a/testcases/lib/tst_net.sh
> > +++ b/testcases/lib/tst_net.sh
> > @@ -869,16 +869,22 @@ tst_netload_compare()
> > local new_time=$2
> > local threshold_low=$3
> > local threshold_hi=$4
> > + local ttype='TFAIL'
> > + local msg res
> > if [ -z "$base_time" -o -z "$new_time" -o -z "$threshold_low" ]; then
> > tst_brk_ TBROK "tst_netload_compare: invalid argument(s)"
> > fi
> > - local res=$(((base_time - new_time) * 100 / base_time))
> > - local msg="performance result is ${res}%"
> > + res=$(((base_time - new_time) * 100 / base_time))
> > + msg="performance result is ${res}%"
> > if [ "$res" -lt "$threshold_low" ]; then
> > - tst_res_ TFAIL "$msg < threshold ${threshold_low}%"
> > + if [ -z "$TST_NET_FEATURES_TEST_PERFORMANCE" ]; then
> > + ttype='TINFO';
> > + tst_res_ TINFO "WARNING: slow performance is not treated as error, change it with TST_NET_FEATURES_TEST_PERFORMANCE=1"

> This TINFO message should probably be moved to tst_net_setup(). Otherwise
> some tests will print it multiple times.

I wanted to print it only when relevant. When added to tst_net_setup() it will
print also for tests which does not use tst_netload_compare(), which is IMHO
worth than printing multiple times the info. I could avoid it with guarding
with a variable (e.g. _tst_net_test_performance_warn_printed, ugly solution but
solves the problem). WDYT?

> I'd also slightly prefer to keep the default as is and use a variable to
> disable perf checks instead.

That's obviously more friendly as it's backward compatible, so I'm ok to send v2
which implements that. The reason why I dared to change the default is that I
haven't seen any report on these tests thus I suspect not many people (if any
outside SUSE) use them. I also wonted to promote them as working tests to the
testing community, but I would recommend to use them only with disabled checks.

Kind regards,
Petr

> > + fi
> > + tst_res_ $ttype "$msg < threshold ${threshold_low}%"
> > return
> > fi
> > diff --git a/testcases/lib/tst_test.sh b/testcases/lib/tst_test.sh
> > index 5f178a1be..06ee6005a 100644
> > --- a/testcases/lib/tst_test.sh
> > +++ b/testcases/lib/tst_test.sh
> > @@ -1,6 +1,6 @@
> > #!/bin/sh
> > # SPDX-License-Identifier: GPL-2.0-or-later
> > -# Copyright (c) Linux Test Project, 2014-2022
> > +# Copyright (c) Linux Test Project, 2014-2023
> > # Author: Cyril Hrubis <chrubis@suse.cz>

> > # LTP test library for shell.
> > @@ -681,7 +681,8 @@ tst_run()
> > NEEDS_KCONFIGS|NEEDS_KCONFIGS_IFS);;
> > IPV6|IPV6_FLAG|IPVER|TEST_DATA|TEST_DATA_IFS);;
> > RETRY_FUNC|RETRY_FN_EXP_BACKOFF|TIMEOUT);;
> > - NET_DATAROOT|NET_MAX_PKT|NET_RHOST_RUN_DEBUG|NETLOAD_CLN_NUMBER);;
> > + NETLOAD_CLN_NUMBER|NET_DATAROOT|NET_FEATURES_TEST_PERFORMANCE);;
> > + NET_MAX_PKT|NET_RHOST_RUN_DEBUG);;
> > NET_SKIP_VARIABLE_INIT|NEEDS_CHECKPOINTS);;
> > CHECKPOINT_WAIT|CHECKPOINT_WAKE);;
> > CHECKPOINT_WAKE2|CHECKPOINT_WAKE_AND_WAIT);;
> > diff --git a/testcases/network/README.md b/testcases/network/README.md
> > index a0a1d3d95..0547c3f9f 100644
> > --- a/testcases/network/README.md
> > +++ b/testcases/network/README.md
> > @@ -84,6 +84,10 @@ Where
> > Default values for all LTP network parameters are set in `testcases/lib/tst_net.sh`.
> > Network stress parameters are documented in `testcases/network/stress/README`.
> > +Tests which use `tst_netload_compare()` test just basic functionality,
> > +performance failure is just printed with 'TINFO'. To enable also performance
> > +testing, set `TST_NET_FEATURES_TEST_PERFORMANCE=1` environment variable.
> > +
> > ## Debugging
> > Both single and two host configurations support debugging via
> > `TST_NET_RHOST_RUN_DEBUG=1` environment variable.