Re: [PATCH] fuzz: avoid building twice, when running on gitlab

[Coiby Xu]

On Tue, Aug 10, 2021 at 07:01:45AM +0200, Philippe Mathieu-Daudé wrote:
> +Coiby Xu & qemu-block@

Thanks for adding me to the Cc list.

> On 8/9/21 9:36 PM, Peter Maydell wrote:
> > On Mon, 9 Aug 2021 at 20:30, Alexander Bulekov <alxndr@bu.edu> wrote:
> > > On 210809 1506, Alexander Bulekov wrote:
> > > > On 210809 1925, Peter Maydell wrote:
> > > > > On Mon, 9 Aug 2021 at 12:18, Alexander Bulekov <alxndr@bu.edu> wrote:
> > > > > > On oss-fuzz, we build twice, to put together a build that is portable to
> > > > > > the runner containers. On gitlab ci, this is wasteful and contributes to
> > > > > > timeouts on the build-oss-fuzz job. Avoid building twice on gitlab, at
> > > > > > the remote cost of potentially missing some cases that break oss-fuzz
> > > > > > builds.
> > > > > >
> > > > > > Signed-off-by: Alexander Bulekov <alxndr@bu.edu>
> > > > > > ---
> > > > > >
> > > > > > From a couple test runs it looks like this can shave off 15-20 minutes.
> > > > > >
> > > > > >  scripts/oss-fuzz/build.sh | 24 +++++++++++++-----------
> > > > > >  1 file changed, 13 insertions(+), 11 deletions(-)
> > > > >
> > > > > I tried a test run with this, but it still hit the 1 hour timeout:
> > > > >
> > > > > https://gitlab.com/qemu-project/qemu/-/pipelines/350387482
> > > >
> > > > It also timed out for me with a 120 minute timeout:
> > > > https://gitlab.com/a1xndr/qemu/-/jobs/1488160601
> > > >
> > > > The log has almost exactly the same number of lines as yours, so I'm
> > > > guessing one of the qtests is timing out with --enable-sanitizers .
> >
> > > Building locally:
> > > $ CC=clang-11 CXX=clang++-11 ../configure --enable-fuzzing \
> > >     --enable-debug --enable-sanitizers
> > > $ make check-qtest-i386 check-unit
> > >
> > > Same as on gitlab, this times out shortly after outputting
> > > "sh: 1: exec: ./storage-daemon/qemu-storage-daemon: not found"
> > >
> > > Manually running qos-test, the same way check-qtest-i386 invokes it:
> > >
> > > $ QTEST_QEMU_BINARY=./qemu-system-i386 
> > > QTEST_QEMU_STORAGE_DAEMON_BINARY=./storage-daemon/qemu-storage-daemon 
> > > tests/qtest/qos-test --tap -k -m quick < /dev/null
> > >
> > > # starting vhost-user backend: exec ./storage-daemon/qemu-storage-daemon 
> > > --blockdev driver=file,node-name=disk0,filename=qtest.XRAzzu --export 
> > > type=vhost-user-blk,id=disk0,addr.type=unix,addr.path=/tmp/qtest-94561-sock.NdKWpt,node-name=disk0,writable=on,num-queues=1
> > > sh: 1: exec: ./storage-daemon/qemu-storage-daemon: not found

The error is different from the previous issue of intermittent hang.
This time the hang is caused by missing qemu-storage-daemon and I
guess the hang could happen reliably each time. The reason of missing 
qemu-storage-daemon is the test doesn't add qemu-storage-daemon as
dependency. If we run `make`, qemu-storage-daemon would be built. But if 
`make check-qtest-i386` is run directly, qemu-storage-daemon wouldn't be 
built. I'll send a patch to make vhost-user-blk test depends on
emu-storage-daemon. 

> > > # starting QEMU: exec ./qemu-system-i386 -qtest unix:/tmp/qtest-94561.sock 
> > > -qtest-log /dev/null -chardev socket,path=/tmp/qtest-94561.qmp,id=char0 -mon 
> > > chardev=char0,mode=control -display none -M pc  -device 
> > > vhost-user-blk-pci,id=drv0,chardev=char1,addr=4.0 -object 
> > > memory-backend-memfd,id=mem,size=256M,share=on  -M memory-backend=mem -m 256M 
> > > -chardev socket id=char1,path=/tmp/qtest-94561-sock.NdKWpt  -accel qtest
> > >
> > > *timeout*
> >
> > vhost-user timing out in realize I suspect. I see that as
> > an intermittent hang in non-sanitizer configs.
> >
> > vhost-user folk: Can we either look at fixing this or else disable
> > the test ? (Stack backtraces available in the other email thread.)
> >
> > thanks
> > -- PMM

--
Best regards,
Coiby