Laurent Desnogues <laurent.desnog...@gmail.com> writes:
> On Thu, Sep 5, 2019 at 5:24 PM Alex Bennée <alex.ben...@linaro.org> wrote: >> >> >> Richard Henderson <richard.hender...@linaro.org> writes: >> >> > This is the payoff. >> > >> > From perf record -g data of ubuntu 18 boot and shutdown: >> > >> > BEFORE: >> > >> > - 23.02% 2.82% qemu-system-aar [.] helper_lookup_tb_ptr >> > - 20.22% helper_lookup_tb_ptr >> > + 10.05% tb_htable_lookup >> > - 9.13% cpu_get_tb_cpu_state >> > 3.20% aa64_va_parameters_both >> > 0.55% fp_exception_el >> > >> > - 11.66% 4.74% qemu-system-aar [.] cpu_get_tb_cpu_state >> > - 6.96% cpu_get_tb_cpu_state >> > 3.63% aa64_va_parameters_both >> > 0.60% fp_exception_el >> > 0.53% sve_exception_el >> > >> > AFTER: >> > >> > - 16.40% 3.40% qemu-system-aar [.] helper_lookup_tb_ptr >> > - 13.03% helper_lookup_tb_ptr >> > + 11.19% tb_htable_lookup >> > 0.55% cpu_get_tb_cpu_state >> > >> > 0.98% 0.71% qemu-system-aar [.] cpu_get_tb_cpu_state >> > >> > 0.87% 0.24% qemu-system-aar [.] rebuild_hflags_a64 >> > >> > Before, helper_lookup_tb_ptr is the second hottest function in the >> > application, consuming almost a quarter of the runtime. Within the >> > entire execution, cpu_get_tb_cpu_state consumes about 12%. >> > >> > After, helper_lookup_tb_ptr has dropped to the fourth hottest function, >> > with consumption dropping to a sixth of the runtime. Within the >> > entire execution, cpu_get_tb_cpu_state has dropped below 1%, and the >> > supporting function to rebuild hflags also consumes about 1%. >> > >> > Assertions are retained for --enable-debug-tcg. >> > >> > Tested-by: Alex Bennée <alex.ben...@linaro.org> >> >> Hmm something must have been missed for M-profile because: >> >> make run-tcg-tests-arm-softmmu V=1 >> >> Leads to: >> >> timeout 15 >> /home/alex/lsrc/qemu.git/builds/all.debug/arm-softmmu/qemu-system-arm >> -monitor none -display none -chardev >> file,path=test-armv6m-undef.out,id=output -semihosting -M microbit -kernel >> test-armv6m-undef >> qemu: fatal: Lockup: can't escalate 3 to HardFault (current priority -1) >> >> R00=00000000 R01=00000000 R02=00000000 R03=00000000 >> R04=00000000 R05=00000000 R06=00000000 R07=00000000 >> R08=00000000 R09=00000000 R10=00000000 R11=00000000 >> R12=00000000 R13=20003fe0 R14=fffffff9 R15=000000c0 >> XPSR=41000003 -Z-- T handler >> FPSCR: 00000000 >> timeout: the monitored command dumped core >> >> But annoyingly not shown up by the debug-tcg verification. The commit >> before works fine. > > There's a typo in the patch: that should not be CONFIG_TCG_DEBUG but > CONFIG_DEBUG_TCG. With this you should see the assert fire. Indeed: cpu_get_tb_cpu_state: cache 110000c0 <> 312000c0 I wish there was an assert form that would handily print out the difference between the two values. I wonder if glib has one... > > I let Richard know that there's an issue with the handling of CPSR E > flag (BE_DATA in hflags). I don't know if that applies to your test. > > Thanks, > > Laurent > >> > Reviewed-by: Alex Bennée <alex.ben...@linaro.org> >> > Signed-off-by: Richard Henderson <richard.hender...@linaro.org> >> > --- >> > v2: Retain asserts for future debugging. >> > --- >> > target/arm/helper.c | 9 ++++++--- >> > 1 file changed, 6 insertions(+), 3 deletions(-) >> > >> > diff --git a/target/arm/helper.c b/target/arm/helper.c >> > index d1bf71a260..5e4f996882 100644 >> > --- a/target/arm/helper.c >> > +++ b/target/arm/helper.c >> > @@ -11211,12 +11211,15 @@ void HELPER(rebuild_hflags_a64)(CPUARMState >> > *env, int el) >> > void cpu_get_tb_cpu_state(CPUARMState *env, target_ulong *pc, >> > target_ulong *cs_base, uint32_t *pflags) >> > { >> > - uint32_t flags, pstate_for_ss; >> > + uint32_t flags = env->hflags; >> > + uint32_t pstate_for_ss; >> > >> > *cs_base = 0; >> > - flags = rebuild_hflags_internal(env); >> > +#ifdef CONFIG_TCG_DEBUG >> > + assert(flags == rebuild_hflags_internal(env)); >> > +#endif >> > >> > - if (is_a64(env)) { >> > + if (FIELD_EX32(flags, TBFLAG_ANY, AARCH64_STATE)) { >> > *pc = env->pc; >> > if (cpu_isar_feature(aa64_bti, env_archcpu(env))) { >> > flags = FIELD_DP32(flags, TBFLAG_A64, BTYPE, env->btype); >> >> >> -- >> Alex Bennée >> -- Alex Bennée