From 106c5118f0063617b868cecf4f580a62d324b5ba Mon Sep 17 00:00:00 2001 From: mprabhu-nokia <66807480+mprabhu-nokia@users.noreply.github.com> Date: Wed, 26 Aug 2020 08:53:50 -0700 Subject: [PATCH] Update pmon-chassis-design.md Updated with 2 approaches to collect thermal info --- doc/pmon/pmon-chassis-design.md | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) diff --git a/doc/pmon/pmon-chassis-design.md b/doc/pmon/pmon-chassis-design.md index fe6b116472..9521866f14 100644 --- a/doc/pmon/pmon-chassis-design.md +++ b/doc/pmon/pmon-chassis-design.md @@ -320,18 +320,21 @@ Thermalctld is monitoring temperatures, monitoring fan speed and allowing polici * Temperature sensors are on the control-card * Temperature sensors are on the line-card * Temperature sensors are on the SFMs. -2. The FAN control is limited to the control-card +2. All thermal sensor info should be available to the control-card. +3. The FAN control is limited to the control-card. The Fan algorithm could be implemented as part of thermal-policy or by the platform. ![Tempearature and Fan Control](pmon-chassis-images/pmon-chassis-distributed-thermalctld.png) #### Proposal 1. Chassisd notified line-card up/down events are subscribed up Thermalctld. 2. All local temperatures sensors are recorded on both control and line-cards for monitoring. The control-card monitors temperature sensors of SFMs. -3. Chassisd on control-card will periodically fetch the summary-info from each of the line-cards. Alternately, the thermalctld on control-card can subscribe for the line-card sensors updates. +3. Chassisd on control-card will periodically fetch/subscribe the thermal-sensors info from each of the line-cards. Alternately, the thermalctld on line-card can directly update the DB on the control-card. 5. The local-temperatures of control-card, line-cards and fabric-cards are passed onto the Fan-Control algorithm. 6. The fan-control algorithm can be implemented ina PMON or ina the platform-driver. -Changes ina thermalctld is to have a TemperatureUpdater class for each line-card. Each of the updater class will fetch the values for all temperature senosors of the line-card from the REDIS-DB of the line-card. +Changes in thermalctld would follow one of the 2 approaches: +1. Have a TemperatureUpdater class for each line-card. Each of the updater class will fetch the values for all temperature senosors of the line-card from the REDIS-DB of the line-card and update the DB on the control-card. +2. The TemperatureUpdater class in each line-card will update the local-DB on its card as well as the global-DB on the control-card. ``` In src/sonic-platform-daemons/sonic-thermalctld/scripts/thermalctld: @@ -371,6 +374,9 @@ class ThermalInfo(ThermalPolicyInfoBase): def collect(self, chassis): #Vendor specific calculation from all available sensor values on chassis ``` + +There could be 2 approaches for where the Fan-Control algorithm could be implemented. + In approach-1, the thermal_policy.json can provide additional action to check if line-card temperature exceeded the threshold etc. The thermalctld.run_policy() will match the required condition and take the appropriate action to set fan speed. In approach-2, the sensors information could be passed on the platform-driver which can then control the fan speed.