From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matthias Kaehlcke Subject: Re: [PATCH v3 1/1] arm64: dts: sdm845: wireup the thermal trip points to cpufreq Date: Thu, 24 Jan 2019 15:35:28 -0800 Message-ID: <20190124233528.GA81583@google.com> References: <6a21a9ee7663e1b32d8ea81ac5e51d187aed25fb.1548093127.git.amit.kucheria@linaro.org> <20190123021251.GJ261387@google.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Return-path: Content-Disposition: inline In-Reply-To: <20190123021251.GJ261387@google.com> Sender: linux-kernel-owner@vger.kernel.org To: Amit Kucheria Cc: linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org, bjorn.andersson@linaro.org, edubezval@gmail.com, andy.gross@linaro.org, tdas@codeaurora.org, swboyd@chromium.org, dianders@chromium.org, David Brown , Rob Herring , Mark Rutland , devicetree@vger.kernel.org List-Id: linux-arm-msm@vger.kernel.org On Tue, Jan 22, 2019 at 06:12:51PM -0800, Matthias Kaehlcke wrote: > Hi Amit, > > On Mon, Jan 21, 2019 at 11:38:34PM +0530, Amit Kucheria wrote: > > Since all cpus in the big and little clusters, respectively, are in the > > same frequency domain, use all of them for mitigation in the > > cooling-map. We end up with two cooling devices - one each for the big > > and little clusters. > > > > We throttle lightly at the first trip point, just removing the boost > > frequency. At the next trip point we allow ourselves to be throttled to > > any extent. > > > > Signed-off-by: Amit Kucheria > > --- > > arch/arm64/boot/dts/qcom/sdm845.dtsi | 225 +++++++++++++++++++++++++-- > > 1 file changed, 209 insertions(+), 16 deletions(-) > > > > diff --git a/arch/arm64/boot/dts/qcom/sdm845.dtsi b/arch/arm64/boot/dts/qcom/sdm845.dtsi > > index c27cbd3bcb0a..878f661d16eb 100644 > > --- a/arch/arm64/boot/dts/qcom/sdm845.dtsi > > +++ b/arch/arm64/boot/dts/qcom/sdm845.dtsi > > @@ -13,6 +13,7 @@ > > #include > > #include > > #include > > +#include > > > > / { > > interrupt-parent = <&intc>; > > @@ -99,6 +100,7 @@ > > compatible = "qcom,kryo385"; > > reg = <0x0 0x0>; > > enable-method = "psci"; > > + #cooling-cells = <2>; > > next-level-cache = <&L2_0>; > > L2_0: l2-cache { > > compatible = "cache"; > > @@ -114,6 +116,7 @@ > > compatible = "qcom,kryo385"; > > reg = <0x0 0x100>; > > enable-method = "psci"; > > + #cooling-cells = <2>; > > next-level-cache = <&L2_100>; > > L2_100: l2-cache { > > compatible = "cache"; > > @@ -126,6 +129,7 @@ > > compatible = "qcom,kryo385"; > > reg = <0x0 0x200>; > > enable-method = "psci"; > > + #cooling-cells = <2>; > > next-level-cache = <&L2_200>; > > L2_200: l2-cache { > > compatible = "cache"; > > @@ -138,6 +142,7 @@ > > compatible = "qcom,kryo385"; > > reg = <0x0 0x300>; > > enable-method = "psci"; > > + #cooling-cells = <2>; > > next-level-cache = <&L2_300>; > > L2_300: l2-cache { > > compatible = "cache"; > > @@ -150,6 +155,7 @@ > > compatible = "qcom,kryo385"; > > reg = <0x0 0x400>; > > enable-method = "psci"; > > + #cooling-cells = <2>; > > next-level-cache = <&L2_400>; > > L2_400: l2-cache { > > compatible = "cache"; > > @@ -162,6 +168,7 @@ > > compatible = "qcom,kryo385"; > > reg = <0x0 0x500>; > > enable-method = "psci"; > > + #cooling-cells = <2>; > > next-level-cache = <&L2_500>; > > L2_500: l2-cache { > > compatible = "cache"; > > @@ -174,6 +181,7 @@ > > compatible = "qcom,kryo385"; > > reg = <0x0 0x600>; > > enable-method = "psci"; > > + #cooling-cells = <2>; > > next-level-cache = <&L2_600>; > > L2_600: l2-cache { > > compatible = "cache"; > > @@ -186,6 +194,7 @@ > > compatible = "qcom,kryo385"; > > reg = <0x0 0x700>; > > enable-method = "psci"; > > + #cooling-cells = <2>; > > next-level-cache = <&L2_700>; > > L2_700: l2-cache { > > compatible = "cache"; > > @@ -1691,18 +1700,41 @@ > > thermal-sensors = <&tsens0 1>; > > > > trips { > > - cpu_alert0: trip0 { > > + cpu0_alert1: trip-point@0 { > > temperature = <75000>; > > In my observations a 'switch on/threshold' temperature of 75 degrees > leads to aggressive throttling with IPA when the temperature is above > this threshold: > > [ 716.760804] cpu_cooling_ratelimit: 31 callbacks suppressed > [ 716.760836] cpu cpu4: Cooling state set to 10. New max freq = 1920000 > [ 716.773390] power_allocator_ratelimit: 15 callbacks suppressed > [ 716.773405] thermal thermal_zone5: Controlling power: control_temp=95000 last_temp=73500, curr_temp=75200 total_requested_power=39025 total_granted_power=18654 > [ 749.609336] cpu_cooling_ratelimit: 45 callbacks suppressed > [ 749.609371] cpu cpu4: Cooling state set to 11. New max freq = 1843200 > [ 749.624300] power_allocator_ratelimit: 24 callbacks suppressed > [ 749.624323] thermal thermal_zone5: Controlling power: control_temp=95000 last_temp=70800, curr_temp=77200 total_requested_power=40136 total_granted_power=17402 > [ 780.152633] cpu_cooling_ratelimit: 41 callbacks suppressed > [ 780.152666] cpu cpu4: Cooling state set to 11. New max freq = 1843200 > [ 780.165247] power_allocator_ratelimit: 21 callbacks suppressed > [ 780.165261] thermal thermal_zone5: Controlling power: control_temp=95000 last_temp=64800, curr_temp=76900 total_requested_power=39719 total_granted_power=1759 > > (the logs come from a local patch in our tree: > https://chromium.googlesource.com/chromiumos/third_party/kernel/+/ec1c501a8093fed44a6697a5913ef2765f518e1f) > > At this point I don't have a clear idea what would be a reasonable > value for the 'switch on/threshold' temperature, but probably it > should to be higher than 75 degrees, at least with IPA. If there is > no reasonable common configuration for different thermal governors I > guess we'll have to target a commonly used governor and systems > using other 'incompatible' governors need to override the config in > their .dtsi. On my system I don't see a significant delta in core temperatures for 'threshold' temperatures of 80, 85 or 90°C. However Dhrystone performance goes up by ~8% when changing the trip point from 80 to 85°C. For a switch from 85 to 90°C I see a ~2% performance delta. For all trip points the average core temperatures are ~80°C (silver) and ~85°C (gold). Interestingly I observed the highest average temperatures with the trip point at 80°C (repeated measurements were taken for different temperatures). Supposedly LMH throttling is disabled in the firmware I used for these tests, however data suggests that it is still active (temperature doesn't rise beyond 95°C, even without throttling in Linux; Dhrystone performance drops when raising the temperature beyond 95°C with a heat gun. I will do some more testing when I get my hands on a FW that effectively disables LMH (or raises the threshold to something like 105°C). >>From the data collected so far I'd suggest a 'threshold' temperature of 90°C or if that seems to high 85°C. Behavior might be different with other thermal governors or without LMH throttling.. > I should also say that the system I'm testing on isn't a > representative environment (if such a thing exists at all...). It > isn't running an upstream kernel (it's a recent version though, > 4.19). We try to stay as close to upstream as possible, however our > tree includes EAS related patches that affect thermal throttling which > haven't landed upstream yet. Also we currently use a guesstimated > value for 'dynamic-power-coefficient', which impacts IPA. And our > device doesn't have it's final thermal envelope yet, possible future > hardware changes (e.g. heatsink) may alter the behavior. > > > hysteresis = <2000>; > > type = "passive"; > > }; > > > > - cpu_crit0: trip1 { > > + cpu0_alert0: trip-point@1 { > > The labels of the two trip points (cpu0_alert0 and cpu0_alert1) are > inverted. > > > + temperature = <95000>; > > + hysteresis = <2000>; > > + type = "passive"; > > + }; > > + > > + cpu0_crit: cpu_crit { > > temperature = <110000>; > > hysteresis = <1000>; > > type = "critical"; > > }; > > }; > > + > > + cooling-maps { > > + map0 { > > + trip = <&cpu0_alert0>; > > + cooling-device = <&CPU0 THERMAL_NO_LIMIT 1>, > > + <&CPU1 THERMAL_NO_LIMIT 1>, > > + <&CPU2 THERMAL_NO_LIMIT 1>, > > + <&CPU3 THERMAL_NO_LIMIT 1>; > > + }; > > With IPA this doesn't really limit throttling to the boost > frequency. Not sure if it has a negative impact, some other platforms > with a thermal configuration that targets IPA only have a cooling map > entry for the 'desired/target' temperature. > > Cheers > > Matthias