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https://github.com/yuzu-emu/unicorn
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210d13ec49
This avoids duplicating code. cpu_exec_step will also use the new common function once we integrate parallel_cpus into tb->cflags. Note that in this commit we also fix a race, described by Richard Henderson during review. Think of this scenario with threads A and B: (A) Lookup succeeds for TB in hash without tb_lock (B) Sets the TB's tb->invalid flag (B) Removes the TB from tb_htable (B) Clears all CPU's tb_jmp_cache (A) Store TB into local tb_jmp_cache Given that order of events, (A) will keep executing that invalid TB until another flush of its tb_jmp_cache happens, which in theory might never happen. We can fix this by checking the tb->invalid flag every time we look up a TB from tb_jmp_cache, so that in the above scenario, next time we try to find that TB in tb_jmp_cache, we won't, and will therefore be forced to look it up in tb_htable. Performance-wise, I measured a small improvement when booting debian-arm. Note that inlining pays off: Performance counter stats for 'taskset -c 0 qemu-system-arm \ -machine type=virt -nographic -smp 1 -m 4096 \ -netdev user,id=unet,hostfwd=tcp::2222-:22 \ -device virtio-net-device,netdev=unet \ -drive file=jessie.qcow2,id=myblock,index=0,if=none \ -device virtio-blk-device,drive=myblock \ -kernel kernel.img -append console=ttyAMA0 root=/dev/vda1 \ -name arm,debug-threads=on -smp 1' (10 runs): Before: 18714.917392 task-clock # 0.952 CPUs utilized ( +- 0.95% ) 23,142 context-switches # 0.001 M/sec ( +- 0.50% ) 1 CPU-migrations # 0.000 M/sec 10,558 page-faults # 0.001 M/sec ( +- 0.95% ) 53,957,727,252 cycles # 2.883 GHz ( +- 0.91% ) [83.33%] 24,440,599,852 stalled-cycles-frontend # 45.30% frontend cycles idle ( +- 1.20% ) [83.33%] 16,495,714,424 stalled-cycles-backend # 30.57% backend cycles idle ( +- 0.95% ) [66.66%] 76,267,572,582 instructions # 1.41 insns per cycle 12,692,186,323 branches # 678.186 M/sec ( +- 0.92% ) [83.35%] 263,486,879 branch-misses # 2.08% of all branches ( +- 0.73% ) [83.34%] 19.648474449 seconds time elapsed ( +- 0.82% ) After, w/ inline (this patch): 18471.376627 task-clock # 0.955 CPUs utilized ( +- 0.96% ) 23,048 context-switches # 0.001 M/sec ( +- 0.48% ) 1 CPU-migrations # 0.000 M/sec 10,708 page-faults # 0.001 M/sec ( +- 0.81% ) 53,208,990,796 cycles # 2.881 GHz ( +- 0.98% ) [83.34%] 23,941,071,673 stalled-cycles-frontend # 44.99% frontend cycles idle ( +- 0.95% ) [83.34%] 16,161,773,848 stalled-cycles-backend # 30.37% backend cycles idle ( +- 0.76% ) [66.67%] 75,786,269,766 instructions # 1.42 insns per cycle 12,573,617,143 branches # 680.708 M/sec ( +- 1.34% ) [83.33%] 260,235,550 branch-misses # 2.07% of all branches ( +- 0.66% ) [83.33%] 19.340502161 seconds time elapsed ( +- 0.56% ) After, w/o inline: 18791.253967 task-clock # 0.954 CPUs utilized ( +- 0.78% ) 23,230 context-switches # 0.001 M/sec ( +- 0.42% ) 1 CPU-migrations # 0.000 M/sec 10,563 page-faults # 0.001 M/sec ( +- 1.27% ) 54,168,674,622 cycles # 2.883 GHz ( +- 0.80% ) [83.34%] 24,244,712,629 stalled-cycles-frontend # 44.76% frontend cycles idle ( +- 1.37% ) [83.33%] 16,288,648,572 stalled-cycles-backend # 30.07% backend cycles idle ( +- 0.95% ) [66.66%] 77,659,755,503 instructions # 1.43 insns per cycle 12,922,780,045 branches # 687.702 M/sec ( +- 1.06% ) [83.34%] 261,962,386 branch-misses # 2.03% of all branches ( +- 0.71% ) [83.35%] 19.700174670 seconds time elapsed ( +- 0.56% ) Backports commit f6bb84d53110398f4899c19dab4e0fe9908ec060 from qemu |
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| .. | ||
| accel | ||
| crypto | ||
| default-configs | ||
| docs | ||
| fpu | ||
| hw | ||
| include | ||
| qapi | ||
| qobject | ||
| qom | ||
| scripts | ||
| target | ||
| tcg | ||
| util | ||
| aarch64.h | ||
| aarch64eb.h | ||
| accel.c | ||
| arm.h | ||
| armeb.h | ||
| atomic_template.h | ||
| CODING_STYLE | ||
| configure | ||
| COPYING | ||
| COPYING.LIB | ||
| cpu-exec-common.c | ||
| cpu-exec.c | ||
| cpus.c | ||
| cputlb.c | ||
| exec.c | ||
| gen_all_header.sh | ||
| glib_compat.c | ||
| HACKING | ||
| header_gen.py | ||
| ioport.c | ||
| LICENSE | ||
| m68k.h | ||
| Makefile | ||
| Makefile.objs | ||
| Makefile.target | ||
| memory.c | ||
| memory_ldst.inc.c | ||
| memory_mapping.c | ||
| mips.h | ||
| mips64.h | ||
| mips64el.h | ||
| mipsel.h | ||
| powerpc.h | ||
| qapi-schema.json | ||
| qemu-timer.c | ||
| rules.mak | ||
| softmmu_template.h | ||
| sparc.h | ||
| sparc64.h | ||
| tcg-runtime.c | ||
| translate-all.c | ||
| translate-all.h | ||
| translate-common.c | ||
| unicorn_common.h | ||
| VERSION | ||
| vl.c | ||
| vl.h | ||
| x86_64.h | ||