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SubjectRe: [PATCH] arm64: hikey960: update idle-states
Hi Vincent,

On Fri, Jul 06, 2018 at 08:57:26AM +0200, Vincent Guittot wrote:
> Update entry/exit latency and residency time of hikey960 to use more
> realistic figures based on unitary tests done on the platform.
>
> The complete results (in us) :
> big cluster
> cluster CPU
> max entry latency 800 400
> max exit latency 2900 550
> residency 903Mhz 5000 1500
> residency 2363Mhz 0 1500
>
> little cluster
> cluster CPU
> max entry latency 500 400
> max exit latency 1600 650
> residency 533Mhz 8000 4500
> residency 1844Mhz 0 1500
>
> We can see that the residency time depends of the running OPP which is not
> handled for now. Then we also have to take into account the constraint of
> a residency time shorter than the tick to get full advantage of idle loop
> reordering(tick is stopped if idle duration is higher than tick period).
> Finally the selected residency value are :
> big cluster
> cluster CPU
> residency 3700 1500
>
> little cluster
> cluster CPU
> residency 3500 1500
>
> A simple test with a task waking up every 11,111ms shows improvement:

Should s/11,111ms/11.111ms ?

> - 5% a lowest OPP
> - 22% at highest OPP
>
> The period has been chosen:
> - to be shorter than old cluster residency time and longer than new
> residency time od cluster off C-state

Should s/od/of/ ?

Except these two minor typos, the patch is very good improvement.

Reviewed-by: Leo Yan <leo.yan@linaro.org>

> - to prevent any sync with tick (4ms) when running tests that can add
> some variances between tests
>
> Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
> ---
> arch/arm64/boot/dts/hisilicon/hi3660.dtsi | 45 ++++++++++++++++++-------------
> 1 file changed, 27 insertions(+), 18 deletions(-)
>
> diff --git a/arch/arm64/boot/dts/hisilicon/hi3660.dtsi b/arch/arm64/boot/dts/hisilicon/hi3660.dtsi
> index 421d454..890d23e 100644
> --- a/arch/arm64/boot/dts/hisilicon/hi3660.dtsi
> +++ b/arch/arm64/boot/dts/hisilicon/hi3660.dtsi
> @@ -61,7 +61,7 @@
> reg = <0x0 0x0>;
> enable-method = "psci";
> next-level-cache = <&A53_L2>;
> - cpu-idle-states = <&CPU_SLEEP &CLUSTER_SLEEP_0>;
> + cpu-idle-states = <&CPU_SLEEP_0 &CLUSTER_SLEEP_0>;
> capacity-dmips-mhz = <592>;
> clocks = <&stub_clock HI3660_CLK_STUB_CLUSTER0>;
> operating-points-v2 = <&cluster0_opp>;
> @@ -75,7 +75,7 @@
> reg = <0x0 0x1>;
> enable-method = "psci";
> next-level-cache = <&A53_L2>;
> - cpu-idle-states = <&CPU_SLEEP &CLUSTER_SLEEP_0>;
> + cpu-idle-states = <&CPU_SLEEP_0 &CLUSTER_SLEEP_0>;
> capacity-dmips-mhz = <592>;
> clocks = <&stub_clock HI3660_CLK_STUB_CLUSTER0>;
> operating-points-v2 = <&cluster0_opp>;
> @@ -87,7 +87,7 @@
> reg = <0x0 0x2>;
> enable-method = "psci";
> next-level-cache = <&A53_L2>;
> - cpu-idle-states = <&CPU_SLEEP &CLUSTER_SLEEP_0>;
> + cpu-idle-states = <&CPU_SLEEP_0 &CLUSTER_SLEEP_0>;
> capacity-dmips-mhz = <592>;
> clocks = <&stub_clock HI3660_CLK_STUB_CLUSTER0>;
> operating-points-v2 = <&cluster0_opp>;
> @@ -99,7 +99,7 @@
> reg = <0x0 0x3>;
> enable-method = "psci";
> next-level-cache = <&A53_L2>;
> - cpu-idle-states = <&CPU_SLEEP &CLUSTER_SLEEP_0>;
> + cpu-idle-states = <&CPU_SLEEP_0 &CLUSTER_SLEEP_0>;
> capacity-dmips-mhz = <592>;
> clocks = <&stub_clock HI3660_CLK_STUB_CLUSTER0>;
> operating-points-v2 = <&cluster0_opp>;
> @@ -111,7 +111,7 @@
> reg = <0x0 0x100>;
> enable-method = "psci";
> next-level-cache = <&A73_L2>;
> - cpu-idle-states = <&CPU_SLEEP &CLUSTER_SLEEP_1>;
> + cpu-idle-states = <&CPU_SLEEP_1 &CLUSTER_SLEEP_1>;
> capacity-dmips-mhz = <1024>;
> clocks = <&stub_clock HI3660_CLK_STUB_CLUSTER1>;
> operating-points-v2 = <&cluster1_opp>;
> @@ -125,7 +125,7 @@
> reg = <0x0 0x101>;
> enable-method = "psci";
> next-level-cache = <&A73_L2>;
> - cpu-idle-states = <&CPU_SLEEP &CLUSTER_SLEEP_1>;
> + cpu-idle-states = <&CPU_SLEEP_1 &CLUSTER_SLEEP_1>;
> capacity-dmips-mhz = <1024>;
> clocks = <&stub_clock HI3660_CLK_STUB_CLUSTER1>;
> operating-points-v2 = <&cluster1_opp>;
> @@ -137,7 +137,7 @@
> reg = <0x0 0x102>;
> enable-method = "psci";
> next-level-cache = <&A73_L2>;
> - cpu-idle-states = <&CPU_SLEEP &CLUSTER_SLEEP_1>;
> + cpu-idle-states = <&CPU_SLEEP_1 &CLUSTER_SLEEP_1>;
> capacity-dmips-mhz = <1024>;
> clocks = <&stub_clock HI3660_CLK_STUB_CLUSTER1>;
> operating-points-v2 = <&cluster1_opp>;
> @@ -149,7 +149,7 @@
> reg = <0x0 0x103>;
> enable-method = "psci";
> next-level-cache = <&A73_L2>;
> - cpu-idle-states = <&CPU_SLEEP &CLUSTER_SLEEP_1>;
> + cpu-idle-states = <&CPU_SLEEP_1 &CLUSTER_SLEEP_1>;
> capacity-dmips-mhz = <1024>;
> clocks = <&stub_clock HI3660_CLK_STUB_CLUSTER1>;
> operating-points-v2 = <&cluster1_opp>;
> @@ -158,31 +158,40 @@
> idle-states {
> entry-method = "psci";
>
> - CPU_SLEEP: cpu-sleep {
> + CPU_SLEEP_0: cpu-sleep-0 {
> compatible = "arm,idle-state";
> local-timer-stop;
> arm,psci-suspend-param = <0x0010000>;
> - entry-latency-us = <40>;
> - exit-latency-us = <70>;
> - min-residency-us = <3000>;
> + entry-latency-us = <400>;
> + exit-latency-us = <650>;
> + min-residency-us = <1500>;
> };
> -
> CLUSTER_SLEEP_0: cluster-sleep-0 {
> compatible = "arm,idle-state";
> local-timer-stop;
> arm,psci-suspend-param = <0x1010000>;
> entry-latency-us = <500>;
> - exit-latency-us = <5000>;
> - min-residency-us = <20000>;
> + exit-latency-us = <1600>;
> + min-residency-us = <3500>;
> + };
> +
> +
> + CPU_SLEEP_1: cpu-sleep-1 {
> + compatible = "arm,idle-state";
> + local-timer-stop;
> + arm,psci-suspend-param = <0x0010000>;
> + entry-latency-us = <400>;
> + exit-latency-us = <550>;
> + min-residency-us = <1500>;
> };
>
> CLUSTER_SLEEP_1: cluster-sleep-1 {
> compatible = "arm,idle-state";
> local-timer-stop;
> arm,psci-suspend-param = <0x1010000>;
> - entry-latency-us = <1000>;
> - exit-latency-us = <5000>;
> - min-residency-us = <20000>;
> + entry-latency-us = <800>;
> + exit-latency-us = <2900>;
> + min-residency-us = <3500>;
> };
> };
>
> --
> 2.7.4
>

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