v5: https://lists.gnu.org/archive/html/qemu-devel/2018-12/msg02979.html
For context, the goal of this series is to substitute the BQL for the per-CPU locks in many places, notably the execution loop in cpus.c. This leads to better scalability for MTTCG, since CPUs don't have to acquire a contended global lock (the BQL) every time they stop executing code. See the last commit for some performance numbers. After this series, the remaining obstacles to achieving KVM-like scalability in MTTCG are: (1) interrupt handling, which in some targets requires the BQL, and (2) frequent execution of "async safe" work. That said, some targets scale great on MTTCG even before this series -- for instance, when running a parallel compilation job in an x86_64 guest, scalability is comparable to what we get with KVM. This series is very long. If you only have time to look at a few patches, I suggest the following, which do most of the heavy lifting and have not yet been reviewed: - Patch 7: cpu: make per-CPU locks an alias of the BQL in TCG rr mode - Patch 70: cpu: protect CPU state with cpu->lock instead of the BQL I've tested all patches with `make check-qtest -j' for all targets. The series is checkpatch-clean (just some warnings about __COVERITY__). You can fetch the series from: https://github.com/cota/qemu/tree/cpu-lock-v6 --- Changes since v5: - Rebase on current master + Fixed a few conflicts, and converted the references to cpu->halted and cpu->interrupt_request that had been added since v5. - Add R-b's and Ack's -- thanks everyone! Thanks, Emilio --- accel/tcg/cpu-exec.c | 40 ++-- accel/tcg/cputlb.c | 10 +- accel/tcg/tcg-all.c | 12 +- accel/tcg/tcg-runtime.c | 7 + accel/tcg/tcg-runtime.h | 2 + accel/tcg/translate-all.c | 2 +- cpus-common.c | 129 ++++++++---- cpus.c | 421 ++++++++++++++++++++++++++++++++-------- exec.c | 2 +- gdbstub.c | 4 +- hw/arm/omap1.c | 4 +- hw/arm/pxa2xx_gpio.c | 2 +- hw/arm/pxa2xx_pic.c | 2 +- hw/intc/s390_flic.c | 4 +- hw/mips/cps.c | 2 +- hw/misc/mips_itu.c | 4 +- hw/openrisc/cputimer.c | 2 +- hw/ppc/e500.c | 4 +- hw/ppc/ppc.c | 12 +- hw/ppc/ppce500_spin.c | 6 +- hw/ppc/spapr_cpu_core.c | 4 +- hw/ppc/spapr_hcall.c | 4 +- hw/ppc/spapr_rtas.c | 6 +- hw/sparc/leon3.c | 2 +- hw/sparc/sun4m.c | 8 +- hw/sparc64/sparc64.c | 8 +- include/qom/cpu.h | 189 +++++++++++++++--- qom/cpu.c | 27 ++- stubs/Makefile.objs | 1 + stubs/cpu-lock.c | 28 +++ target/alpha/cpu.c | 8 +- target/alpha/translate.c | 6 +- target/arm/arm-powerctl.c | 4 +- target/arm/cpu.c | 8 +- target/arm/helper.c | 16 +- target/arm/machine.c | 2 +- target/arm/op_helper.c | 2 +- target/cris/cpu.c | 2 +- target/cris/helper.c | 6 +- target/cris/translate.c | 5 +- target/hppa/cpu.c | 2 +- target/hppa/translate.c | 3 +- target/i386/cpu.c | 4 +- target/i386/cpu.h | 2 +- target/i386/hax-all.c | 36 ++-- target/i386/helper.c | 8 +- target/i386/hvf/hvf.c | 16 +- target/i386/hvf/x86hvf.c | 38 ++-- target/i386/kvm.c | 78 ++++---- target/i386/misc_helper.c | 2 +- target/i386/seg_helper.c | 13 +- target/i386/svm_helper.c | 6 +- target/i386/whpx-all.c | 57 +++--- target/lm32/cpu.c | 2 +- target/lm32/op_helper.c | 4 +- target/m68k/cpu.c | 2 +- target/m68k/op_helper.c | 2 +- target/m68k/translate.c | 9 +- target/microblaze/cpu.c | 2 +- target/microblaze/translate.c | 4 +- target/mips/cpu.c | 11 +- target/mips/kvm.c | 4 +- target/mips/op_helper.c | 8 +- target/mips/translate.c | 4 +- target/moxie/cpu.c | 2 +- target/nios2/cpu.c | 2 +- target/openrisc/cpu.c | 4 +- target/openrisc/sys_helper.c | 4 +- target/ppc/excp_helper.c | 8 +- target/ppc/helper_regs.h | 2 +- target/ppc/kvm.c | 8 +- target/ppc/translate.c | 6 +- target/ppc/translate_init.inc.c | 36 ++-- target/riscv/cpu.c | 5 +- target/riscv/op_helper.c | 2 +- target/s390x/cpu.c | 28 ++- target/s390x/excp_helper.c | 4 +- target/s390x/kvm.c | 2 +- target/s390x/sigp.c | 8 +- target/sh4/cpu.c | 2 +- target/sh4/helper.c | 2 +- target/sh4/op_helper.c | 2 +- target/sparc/cpu.c | 6 +- target/sparc/helper.c | 2 +- target/unicore32/cpu.c | 2 +- target/unicore32/softmmu.c | 2 +- target/xtensa/cpu.c | 6 +- target/xtensa/exc_helper.c | 2 +- target/xtensa/helper.c | 2 +- 89 files changed, 1018 insertions(+), 455 deletions(-)
