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[v5,00/10] tracing: remove dynamic vcpu state

Message ID 20230524133952.3971948-1-alex.bennee@linaro.org
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Series tracing: remove dynamic vcpu state | expand

Message

Alex Bennée May 24, 2023, 1:39 p.m. UTC 
Hi Stefan,

The references dynamic vcpu tracing support was removed when the
original TCG trace points where removed. However there was still a
legacy of dynamic trace state to track this in cpu.h and extra hash
variables to track TBs. While the removed vcpu tracepoints are not in
generated code (or helpers) they still bring in a bunch of machinery
to manage the state so I've pulled them out. We keep and rename one
(cpu_reset) to a static trace points which dump vcpu->index as it is
useful to f4bug.

v5 added f4bug's rb, minor reword of state and rth's suggested tweak for xxhash

Please queue into your tree.

Alex Bennée (10):
  *-user: remove the guest_user_syscall tracepoints
  trace-events: remove the remaining vcpu trace events
  trace: remove vcpu_id from the TraceEvent structure
  scripts/qapi: document the tool that generated the file
  qapi: make the vcpu parameters deprecated for 8.1
  trace: remove code that depends on setting vcpu
  trace: remove control-vcpu.h
  tcg: remove the final vestiges of dstate
  hw/9pfs: use qemu_xxhash4
  accel/tcg: include cs_base in our hash calculations

 docs/about/deprecated.rst     |   9 +++
 qapi/trace.json               |  40 ++++++-------
 accel/tcg/tb-hash.h           |   6 +-
 include/exec/exec-all.h       |   3 -
 include/hw/core/cpu.h         |   5 --
 include/qemu/xxhash.h         |  23 +++++--
 include/user/syscall-trace.h  |   4 --
 trace/control-internal.h      |  10 ----
 trace/control-vcpu.h          |  63 --------------------
 trace/control.h               |  48 ---------------
 trace/event-internal.h        |   2 -
 accel/tcg/cpu-exec.c          |   7 +--
 accel/tcg/tb-maint.c          |   5 +-
 accel/tcg/translate-all.c     |   6 --
 bsd-user/freebsd/os-syscall.c |   2 -
 hw/9pfs/9p.c                  |   5 +-
 hw/core/cpu-common.c          |   6 +-
 stubs/trace-control.c         |  13 ----
 trace/control-target.c        | 109 +++-------------------------------
 trace/control.c               |  28 ---------
 trace/qmp.c                   |  76 +++---------------------
 trace/trace-hmp-cmds.c        |  18 +-----
 util/qsp.c                    |   2 +-
 hw/core/trace-events          |   3 +
 scripts/qapi/gen.py           |   8 ++-
 scripts/tracetool/format/c.py |   6 --
 scripts/tracetool/format/h.py |  16 +----
 trace-events                  |  50 ----------------
 28 files changed, 86 insertions(+), 487 deletions(-)
 delete mode 100644 trace/control-vcpu.h

Comments

Richard Henderson May 26, 2023, 4:15 p.m. UTC | #1 
On 5/24/23 06:39, Alex Bennée wrote:
> 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>
> Message-Id:<20230523125000.3674739-11-alex.bennee@linaro.org>

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>


r~