On Wed, Jun 07, 2017 at 15:22:48 +0100, Alex Bennée wrote: > > Alex Bennée <alex.ben...@linaro.org> writes: > > > Richard Henderson <r...@twiddle.net> writes: > > > >> From: "Emilio G. Cota" <c...@braap.org> > >> > >> Measurements: > >> > >> [Baseline performance is that before applying this and the previous > >> commit] > > > > Sadly this has regressed my qemu-system-aarch64 EL2 run. It was slightly > > masked by an unrelated assertion breakage which I had to fix. However > > with this patch my boot hangs spinning all 4 threads. Once reverted > > things work again. > > > > My command line: > > > > timeout -k 1s --foreground 120s ./aarch64-softmmu/qemu-system-aarch64 > > -machine type=virt -display none -m 4096 -cpu cortex-a57 -serial mon:stdio > > -netdev user,id=unet -device virtio-net-device,netdev=unet -drive > > file=/home/alex/lsrc/qemu/images/jessie-arm64.qcow2,id=myblock,index=0,if=none > > -device virtio-blk-device,drive=myblock -append "console=ttyAMA0 > > root=/dev/vda1 systemd.unit=benchmark.service" -kernel > > /home/alex/lsrc/qemu/images/aarch64-current-linux-kernel-only.img -smp 4 > > -machine gic-version=3 -machine virtualization=true -name debug-threads=on > > > > My tree with fix and revert: > > > > https://github.com/stsquad/qemu/tree/debug/aarch64-hang > > > > I'm investigating now. > > Well this seems to be a case of hangs with -smp > 1 (which I guess was > obvious seeing as the TCG threads seem to be spinning against each > other).
Not sure the problem is in MTTCG; I cannot reproduce with -smp > 1 and thread=single; can you? [ I get no output whatsoever when trying to boot ] Note that you'll need to revert bde4d9205ee to get thread=foo to work again -- see [1]. Thanks, E. [1] https://lists.gnu.org/archive/html/qemu-devel/2017-06/msg01980.html