From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([209.51.188.92]:47188) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gwPBl-0004RO-3J for qemu-devel@nongnu.org; Wed, 20 Feb 2019 05:33:18 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gwPBi-0002j1-VZ for qemu-devel@nongnu.org; Wed, 20 Feb 2019 05:33:16 -0500 Received: from mail-wr1-x441.google.com ([2a00:1450:4864:20::441]:47055) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1gwPBf-0002gs-EH for qemu-devel@nongnu.org; Wed, 20 Feb 2019 05:33:13 -0500 Received: by mail-wr1-x441.google.com with SMTP id i16so17107788wrs.13 for ; Wed, 20 Feb 2019 02:33:09 -0800 (PST) References: <20190219233421.388-1-richard.henderson@linaro.org> <20190219233421.388-4-richard.henderson@linaro.org> From: Alex =?utf-8?Q?Benn=C3=A9e?= In-reply-to: <20190219233421.388-4-richard.henderson@linaro.org> Date: Wed, 20 Feb 2019 10:33:07 +0000 Message-ID: <87zhqq4un0.fsf@zen.linaroharston> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] [PATCH v2 3/3] target/arm: Rely on hflags correct in cpu_get_tb_cpu_state List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Richard Henderson Cc: qemu-devel@nongnu.org, peter.maydell@linaro.org, cota@braap.org Richard Henderson 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. > > Signed-off-by: Richard Henderson Reviewed-by: Alex Benn=C3=A9e Tested-by: Alex Benn=C3=A9e > --- > v2: Retain asserts for future debugging. > --- > target/arm/helper.c | 20 +++++++++++++++----- > 1 file changed, 15 insertions(+), 5 deletions(-) > > diff --git a/target/arm/helper.c b/target/arm/helper.c > index 909535a3e3..990a87876f 100644 > --- a/target/arm/helper.c > +++ b/target/arm/helper.c > @@ -14034,19 +14034,29 @@ void HELPER(rebuild_hflags_a64)(CPUARMState *en= v, uint32_t el) > void cpu_get_tb_cpu_state(CPUARMState *env, target_ulong *pc, > target_ulong *cs_base, uint32_t *pflags) > { > - int current_el =3D arm_current_el(env); > - uint32_t flags; > + uint32_t flags =3D env->hflags; > uint32_t pstate_for_ss; > > +#ifdef CONFIG_DEBUG_TCG > + { > + int el =3D arm_current_el(env); > + uint32_t check_flags; > + if (is_a64(env)) { > + check_flags =3D rebuild_hflags_a64(env, el); > + } else { > + check_flags =3D rebuild_hflags_a32(env, el); > + } > + g_assert_cmphex(flags, =3D=3D, check_flags); > + } > +#endif > + > *cs_base =3D 0; > - if (is_a64(env)) { > + if (FIELD_EX32(flags, TBFLAG_ANY, AARCH64_STATE)) { > *pc =3D env->pc; > - flags =3D rebuild_hflags_a64(env, current_el); > flags =3D FIELD_DP32(flags, TBFLAG_A64, BTYPE, env->btype); > pstate_for_ss =3D env->pstate; > } else { > *pc =3D env->regs[15]; > - flags =3D rebuild_hflags_a32(env, current_el); > flags =3D FIELD_DP32(flags, TBFLAG_A32, THUMB, env->thumb); > flags =3D FIELD_DP32(flags, TBFLAG_A32, CONDEXEC, env->condexec_= bits); > pstate_for_ss =3D env->uncached_cpsr; -- Alex Benn=C3=A9e