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367189ef |
| 26-May-2023 |
Alex Bennée <alex.bennee@linaro.org> |
accel/tcg: include cs_base in our hash calculations
We weren't using cs_base in the hash calculations before. Since the arm front end moved a chunk of flags in a378206a20 (target/arm: Move mode spec
accel/tcg: include cs_base in our hash calculations
We weren't using cs_base in the hash calculations before. Since the arm front end moved a chunk of flags in a378206a20 (target/arm: Move mode specific TB flags to tb->cs_base) they comprise of an important part of the execution state.
Widen the tb_hash_func to include cs_base and expand to qemu_xxhash8() to accommodate it.
My initial benchmark shows very little difference in the runtime.
Before:
armhf
➜ hyperfine -w 2 -m 20 "./arm-softmmu/qemu-system-arm -cpu cortex-a15 -machine type=virt,highmem=off -display none -m 2048 -serial mon:stdio -netdev user,id=unet,hostfwd=tcp::2222-:22 -device virtio-net-pci,netdev=unet -device virtio-scsi-pci -blockdev driver=raw,node-name=hd,discard=unmap,file.driver=host_device,file.filename=/dev/zen-disk/debian-bullseye-armhf -device scsi-hd,drive=hd -smp 4 -kernel /home/alex/lsrc/linux.git/builds/arm/arch/arm/boot/zImage -append 'console=ttyAMA0 root=/dev/sda2 systemd.unit=benchmark.service' -snapshot" Benchmark 1: ./arm-softmmu/qemu-system-arm -cpu cortex-a15 -machine type=virt,highmem=off -display none -m 2048 -serial mon:stdio -netdev user,id=unet,hostfwd=tcp::2222-:22 -device virtio-net-pci,netdev=unet -device virtio-scsi-pci -blockdev driver=raw,node-name=hd,discard=unmap,file.driver=host_device,file.filename=/dev/zen-disk/debian-bullseye-armhf -device scsi-hd,drive=hd -smp 4 -kernel /home/alex/lsrc/linux.git/builds/arm/arch/arm/boot/zImage -append 'console=ttyAMA0 root=/dev/sda2 systemd.unit=benchmark.service' -snapshot Time (mean ± σ): 24.627 s ± 2.708 s [User: 34.309 s, System: 1.797 s] Range (min … max): 22.345 s … 29.864 s 20 runs
arm64
➜ hyperfine -w 2 -n 20 "./qemu-system-aarch64 -cpu max,pauth-impdef=on -machine type=virt,virtualization=on,gic-version=3 -display none -serial mon:stdio -netdev user,id=unet,hostfwd=tcp::2222-:22,hostfwd=tcp::1234-:1234 -device virtio-net-pci,netdev=unet -device virtio-scsi-pci -blockdev driver=raw,node-name=hd,discard=unmap,file.driver=host_device,file.filename=/dev/zen-disk/debian-bullseye-arm64 -device scsi-hd,drive=hd -smp 4 -kernel ~/lsrc/linux.git/builds/arm64/arch/arm64/boot/Image.gz -append 'console=ttyAMA0 root=/dev/sda2 systemd.unit=benchmark-pigz.service' -snapshot" Benchmark 1: 20 Time (mean ± σ): 62.559 s ± 2.917 s [User: 189.115 s, System: 4.089 s] Range (min … max): 59.997 s … 70.153 s 10 runs
After:
armhf
Benchmark 1: ./arm-softmmu/qemu-system-arm -cpu cortex-a15 -machine type=virt,highmem=off -display none -m 2048 -serial mon:stdio -netdev user,id=unet,hostfwd=tcp::2222-:22 -device virtio-net-pci,netdev=unet -device virtio-scsi-pci -blockdev driver=raw,node-name=hd,discard=unmap,file.driver=host_device,file.filename=/dev/zen-disk/debian-bullseye-armhf -device scsi-hd,drive=hd -smp 4 -kernel /home/alex/lsrc/linux.git/builds/arm/arch/arm/boot/zImage -append 'console=ttyAMA0 root=/dev/sda2 systemd.unit=benchmark.service' -snapshot Time (mean ± σ): 24.223 s ± 2.151 s [User: 34.284 s, System: 1.906 s] Range (min … max): 22.000 s … 28.476 s 20 runs
arm64
hyperfine -w 2 -n 20 "./qemu-system-aarch64 -cpu max,pauth-impdef=on -machine type=virt,virtualization=on,gic-version=3 -display none -serial mon:stdio -netdev user,id=unet,hostfwd=tcp::2222-:22,hostfwd=tcp::1234-:1234 -device virtio-net-pci,netdev=unet -device virtio-scsi-pci -blockdev driver=raw,node-name=hd,discard=unmap,file.driver=host_device,file.filename=/dev/zen-disk/debian-bullseye-arm64 -device scsi-hd,drive=hd -smp 4 -kernel ~/lsrc/linux.git/builds/arm64/arch/arm64/boot/Image.gz -append 'console=ttyAMA0 root=/dev/sda2 systemd.unit=benchmark-pigz.service' -snapshot" Benchmark 1: 20 Time (mean ± σ): 62.769 s ± 1.978 s [User: 188.431 s, System: 5.269 s] Range (min … max): 60.285 s … 66.868 s 10 runs
Signed-off-by: Alex Bennée <alex.bennee@linaro.org> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Message-id: 20230526165401.574474-12-alex.bennee@linaro.org Message-Id: <20230524133952.3971948-11-alex.bennee@linaro.org> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
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#
d0aaf08b |
| 26-May-2023 |
Alex Bennée <alex.bennee@linaro.org> |
tcg: remove the final vestiges of dstate
Now we no longer have dynamic state affecting things we can remove the additional fields in cpu.h and simplify the TB hash calculation.
For the benchmark:
tcg: remove the final vestiges of dstate
Now we no longer have dynamic state affecting things we can remove the additional fields in cpu.h and simplify the TB hash calculation.
For the benchmark:
hyperfine -w 2 -m 20 \ "./arm-softmmu/qemu-system-arm -cpu cortex-a15 \ -machine type=virt,highmem=off \ -display none -m 2048 \ -serial mon:stdio \ -netdev user,id=unet,hostfwd=tcp::2222-:22 \ -device virtio-net-pci,netdev=unet \ -device virtio-scsi-pci \ -blockdev driver=raw,node-name=hd,discard=unmap,file.driver=host_device,file.filename=/dev/zen-disk/debian-bullseye-armhf \ -device scsi-hd,drive=hd -smp 4 \ -kernel /home/alex/lsrc/linux.git/builds/arm/arch/arm/boot/zImage \ -append 'console=ttyAMA0 root=/dev/sda2 systemd.unit=benchmark.service' \ -snapshot"
It has a marginal effect on runtime, before:
Time (mean ± σ): 26.279 s ± 2.438 s [User: 41.113 s, System: 1.843 s] Range (min … max): 24.420 s … 32.565 s 20 runs
after:
Time (mean ± σ): 24.440 s ± 2.885 s [User: 34.474 s, System: 2.028 s] Range (min … max): 21.663 s … 29.937 s 20 runs
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1358 Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org> Signed-off-by: Alex Bennée <alex.bennee@linaro.org> Message-id: 20230526165401.574474-10-alex.bennee@linaro.org Message-Id: <20230524133952.3971948-9-alex.bennee@linaro.org> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
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