From 367189efae8b53ec2ade37a1c079fd8f69244b9e Mon Sep 17 00:00:00 2001 From: Alex Bennée Date: Fri, 26 May 2023 17:54:01 +0100 Subject: accel/tcg: include cs_base in our hash calculations MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Reviewed-by: Richard Henderson Message-id: 20230526165401.574474-12-alex.bennee@linaro.org Message-Id: <20230524133952.3971948-11-alex.bennee@linaro.org> Signed-off-by: Stefan Hajnoczi --- accel/tcg/cpu-exec.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'accel/tcg/cpu-exec.c') diff --git a/accel/tcg/cpu-exec.c b/accel/tcg/cpu-exec.c index 4a1dce98ff..60ca9e229e 100644 --- a/accel/tcg/cpu-exec.c +++ b/accel/tcg/cpu-exec.c @@ -233,7 +233,7 @@ static TranslationBlock *tb_htable_lookup(CPUState *cpu, target_ulong pc, } desc.page_addr0 = phys_pc; h = tb_hash_func(phys_pc, (cflags & CF_PCREL ? 0 : pc), - flags, cflags); + flags, cs_base, cflags); return qht_lookup_custom(&tb_ctx.htable, &desc, h, tb_lookup_cmp); } -- cgit 1.4.1