Re: [dpdk-dev] [PATCH] test/interrupt: account for race with callback

[Thomas Monjalon <thomas@monjalon.net>]

09/08/2019 11:18, David Marchand:
> On Thu, Aug 8, 2019 at 7:38 PM Aaron Conole <aconole@redhat.com> wrote:
> >
> > Because the eal interrupt framework can race when invoking the callback
> > and a separate unregister call, the test needs to accommodate the chance
> > that the two collide.  Do this by checking the return value of unregister
> > against the race-condition flag (EAGAIN).
> >
> > Fixes: f1a6c22424ce ("app/test: update interrupts test")
> 
> Not too sure about this tag, but anyway, this is old enough to apply
> to every stable releases we have.
> Cc: stable@dpdk.org ?
> 
> > Signed-off-by: Aaron Conole <aconole@redhat.com>
> > ---
> > NOTE: it's difficult to reproduce this race.  I tried a bit, but have
> >       only seen it sporadically.  In Travis environment, the CPU
> >       resource can be very limited and this test is quite racy.
> 
> Managed to reproduce it:
> 
> # time (log=/tmp/$$.log; while true; do echo interrupt_autotest
> |taskset -c 0-1 ./build-gcc-static/app/test/dpdk-test -l 0-1 >$log
> 2>&1; grep -q 'Test OK' $log || break; done; cat $log; rm -f $log)
> EAL: Detected 8 lcore(s)
> EAL: Detected 1 NUMA nodes
> EAL: Multi-process socket /var/run/dpdk/rte/mp_socket
> EAL: Selected IOVA mode 'PA'
> EAL: No available hugepages reported in hugepages-1048576kB
> EAL: Probing VFIO support...
> EAL: PCI device 0000:00:1f.6 on NUMA socket -1
> EAL:   Invalid NUMA socket, default to 0
> EAL:   probe driver: 8086:15d7 net_e1000_em
> APP: HPET is not enabled, using TSC as default timer
> RTE>>interrupt_autotest
> Check unknown valid interrupt full path
> Check valid UIO interrupt full path
> Check valid device event interrupt full path
> count=-11 Resource temporarily unavailable
> failure occurred during checking valid device event interrupt full path
> Clearing for interrupt tests
> Test Failed
> RTE>>
> real    0m38.081s
> user    0m35.836s
> sys    0m2.171s
> 
> With this patch, my loop has been running for more than 10 minutes now.
> Reviewed-by: David Marchand <david.marchand@redhat.com>

Applied, thanks