Re: [Qemu-devel] [Qemu-block] [PATCH v5 2/6] iotests: exclude killed processes from running under Valgrind

[John Snow <jsnow@redhat.com>]

On 7/19/19 12:30 PM, Andrey Shinkevich wrote:
>  The Valgrind tool fails to manage its termination when QEMU raises the
>  signal SIGKILL in the multi-threaded process. The bug has been
>  reported to the Valgrind maintainers and was registered as Bug 409141.
>  Let's exclude such test cases from running under the Valgrind until
>  new release of it because checking for the memory issues is covered by
>  other test cases.
> 

Link to the bug in the commit message, please:
https://bugs.kde.org/show_bug.cgi?id=409141

...Hey! It looks like they may have fixed it. However, we don't know if
the user has a properly fixed version of valgrind or not.

How long do we keep these workarounds in-tree?

> Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
> ---
>  tests/qemu-iotests/039 | 5 +++++
>  tests/qemu-iotests/061 | 2 ++
>  tests/qemu-iotests/137 | 1 +
>  3 files changed, 8 insertions(+)
> 
> diff --git a/tests/qemu-iotests/039 b/tests/qemu-iotests/039
> index 0d4e963..95115e2 100755
> --- a/tests/qemu-iotests/039
> +++ b/tests/qemu-iotests/039
> @@ -65,6 +65,7 @@ echo "== Creating a dirty image file =="
>  IMGOPTS="compat=1.1,lazy_refcounts=on"
>  _make_test_img $size
>  
> +VALGRIND_QEMU="" \
>  $QEMU_IO -c "write -P 0x5a 0 512" \
>           -c "sigraise $(kill -l KILL)" "$TEST_IMG" 2>&1 \
>      | _filter_qemu_io
> @@ -100,6 +101,7 @@ echo "== Opening a dirty image read/write should repair it =="
>  IMGOPTS="compat=1.1,lazy_refcounts=on"
>  _make_test_img $size
>  

This seems like the sort of thing that's going to get forgotten about
quickly. It's not clear (if you're reading the test source) why we're
setting VALGRIND_QEMU="" before these invocations.

Is it possible to create some kind of _NO_VALGRIND() shim that has some
comment in it, like:

# Valgrind bug #409141 https://bugs.kde.org/show_bug.cgi?id=409141
# Until valgrind 3.16+ is ubiquitous, we must work around a hang in
# valgrind when issuing sigkill. Disable valgrind for this invocation.

VALGRIND_QEMU="" exec "$@"

(something like that.)

This way:

(1) The workaround is being clearly demonstrated as a bit of a hack
(2) The shim explains what the hack is for
(3) When we decide we no longer need the hack, we can pull it out of a
central location and easily grep to find callers of the shim.


> +VALGRIND_QEMU="" \
>  $QEMU_IO -c "write -P 0x5a 0 512" \
>           -c "sigraise $(kill -l KILL)" "$TEST_IMG" 2>&1 \
>      | _filter_qemu_io
> @@ -118,6 +120,7 @@ echo "== Creating an image file with lazy_refcounts=off =="
>  IMGOPTS="compat=1.1,lazy_refcounts=off"
>  _make_test_img $size
>  
> +VALGRIND_QEMU="" \
>  $QEMU_IO -c "write -P 0x5a 0 512" \
>           -c "sigraise $(kill -l KILL)" "$TEST_IMG" 2>&1 \
>      | _filter_qemu_io
> @@ -151,6 +154,7 @@ echo "== Changing lazy_refcounts setting at runtime =="
>  IMGOPTS="compat=1.1,lazy_refcounts=off"
>  _make_test_img $size
>  
> +VALGRIND_QEMU="" \
>  $QEMU_IO -c "reopen -o lazy-refcounts=on" \
>           -c "write -P 0x5a 0 512" \
>           -c "sigraise $(kill -l KILL)" "$TEST_IMG" 2>&1 \
> @@ -163,6 +167,7 @@ _check_test_img
>  IMGOPTS="compat=1.1,lazy_refcounts=on"
>  _make_test_img $size
>  
> +VALGRIND_QEMU="" \
>  $QEMU_IO -c "reopen -o lazy-refcounts=off" \
>           -c "write -P 0x5a 0 512" \
>           -c "sigraise $(kill -l KILL)" "$TEST_IMG" 2>&1 \
> diff --git a/tests/qemu-iotests/061 b/tests/qemu-iotests/061
> index d7dbd7e..5d0724c 100755
> --- a/tests/qemu-iotests/061
> +++ b/tests/qemu-iotests/061
> @@ -73,6 +73,7 @@ echo
>  echo "=== Testing dirty version downgrade ==="
>  echo
>  IMGOPTS="compat=1.1,lazy_refcounts=on" _make_test_img 64M
> +VALGRIND_QEMU="" \
>  $QEMU_IO -c "write -P 0x2a 0 128k" -c flush \
>           -c "sigraise $(kill -l KILL)" "$TEST_IMG" 2>&1 | _filter_qemu_io
>  $PYTHON qcow2.py "$TEST_IMG" dump-header
> @@ -107,6 +108,7 @@ echo
>  echo "=== Testing dirty lazy_refcounts=off ==="
>  echo
>  IMGOPTS="compat=1.1,lazy_refcounts=on" _make_test_img 64M
> +VALGRIND_QEMU="" \
>  $QEMU_IO -c "write -P 0x2a 0 128k" -c flush \
>           -c "sigraise $(kill -l KILL)" "$TEST_IMG" 2>&1 | _filter_qemu_io
>  $PYTHON qcow2.py "$TEST_IMG" dump-header
> diff --git a/tests/qemu-iotests/137 b/tests/qemu-iotests/137
> index 0c3d2a1..a442fc8 100755
> --- a/tests/qemu-iotests/137
> +++ b/tests/qemu-iotests/137
> @@ -130,6 +130,7 @@ echo
>  
>  # Whether lazy-refcounts was actually enabled can easily be tested: Check if
>  # the dirty bit is set after a crash
> +VALGRIND_QEMU="" \
>  $QEMU_IO \
>      -c "reopen -o lazy-refcounts=on,overlap-check=blubb" \
>      -c "write -P 0x5a 0 512" \
>