qemu/accel
Alex Bennée d0aaf08bb9 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>
2023-06-01 11:05:05 -04:00
..
hvf Fix 'writeable' typos 2022-06-08 19:38:47 +01:00
kvm kvm: Enable dirty ring for arm64 2023-05-18 08:53:51 +02:00
qtest accel/qtest: Support qtest accelerator for Windows 2022-10-28 11:17:12 +02:00
stubs includes: move tb_flush into its own header 2023-03-07 17:06:33 +00:00
tcg tcg: remove the final vestiges of dstate 2023-06-01 11:05:05 -04:00
xen accel/xen: Fix DM state change notification in dm_restrict mode 2023-03-23 09:56:54 +00:00
accel-blocker.c accel: introduce accelerator blocker API 2023-01-11 09:59:39 +01:00
accel-common.c gdbstub: move sstep flags probing into AccelClass 2022-10-06 11:53:41 +01:00
accel-softmmu.c *: Add missing includes of qemu/error-report.h 2023-03-22 15:06:57 +00:00
accel-softmmu.h accel: replace struct CpusAccel with AccelOpsClass 2021-02-05 10:24:15 -10:00
accel-user.c accel: extend AccelState and AccelClass to user-mode 2021-02-05 10:24:15 -10:00
dummy-cpus.c accel/qtest: Support qtest accelerator for Windows 2022-10-28 11:17:12 +02:00
Kconfig Add NVMM accelerator: configure and build logic 2021-05-04 14:15:34 +02:00
meson.build accel: introduce accelerator blocker API 2023-01-11 09:59:39 +01:00