Doc: Update Classifier documentation (#126)

Signed-off-by: Jagadeesh Pagadala <jpagadal@qti.qualcomm.com>

Author: jpagadal

docs/README.md

@@ -97,12 +97,75 @@ Userspace resource manager (uRM) contains
 - Extension interface provides a way to customize resource-tuner behaviour, by specifying custom resources, custom signals and features.
 - Resource-tuner uses YAML based config files, for fetching information relating to resources/signals and properties.
 ## Contextual Classifier
-- Contextual Classifier identifies usecase type based on offline trained model
-- Sends signals to Resource Tuner on app opening or launching with app pid and use-case type
-- Extracts use-case's further details based on app pid
-- Moves focused active app's threads to "Focused" cgroup
-- Move previously focused app threads to its origional group
-- This is an optional module which can be enabled at compile time
+The Contextual Classifier is an optional module designed to identify the static context of workloads (e.g., whether an application is a game, multimedia app, or browser) based on an offline-trained model.
+
+**Key functionalities include:**
+- **Process Event Monitoring:** Monitors process creation and termination events via Netlink.
+- **Process Classification:** Classifies workloads (e.g., game, multimedia) using fastText (if enabled at build time). If fastText is not built, a default inference mechanism that always classifies the workload as an application.
+- **Signal Generation:** Retrieves specific signal details based on classified workload types.
+- **Cgroup Management:** Dynamically manages cgroups by moving application threads to designated cgroups.
+- **Action Application:** Calls `ApplyActions` to send tuning requests and `RemoveActions` to untune for process events.
+- **Configurability:** Influenced by configuration files such as `fasttext_model_supervised.bin`, `classifier-blocklist.txt`, and `ignore-tokens.txt`.
+
+**Flow of Events:**
+
+```
++---------------------------+
+| Process Event Listener    |
+|       (NetLinkComm)       |
++-------------+-------------+
+              |
+              | Catches process events (e.g., fork, exec, exit)
+              V
++---------------------------+
+|      HandleProcEv()       |
+| (Filters and queues events)|
++-------------+-------------+
+              |
+              | Notifies worker thread
+              V
++---------------------------+
+|     ClassifierMain()      |
+|    (Worker Thread)        |
++-------------+-------------+
+              |
+              +----(Event Type)----+
+              |                     |
+              V                     V
+        +------------+        +------------+
+        | CC_APP_OPEN|        | CC_APP_CLOSE|
+        +-----+------+        +-----+------+
+              |                     |
+              V                     V
+   +-----------------------+    +---------------------------+
+   | Is Ignored Process?   |--->| Move Process to Original  |
+   | (classifier-blocklist)|    |   Cgroup                  |
+   +----------+------------+    +---+-----------------------+
+              |  No                 |
+              V                     V
+   +---------------------+   +---------------------------+
+   |  ClassifyProcess()  |   |   RemoveActions           |
+   | (MLInference model) |   |    (untuneSignal)         |
+   +----------+----------+   +---------------------------+
+              |
+              V
+   +---------------------+
+   | GetSignalDetailsFor |
+   |      Workload()     |
+   +----------+----------+
+              |
+              V
+   +----------------------------+
+   | MoveAppThreadsToCGroup()   |
+   | (Assign to Focused Cgroup) |
+   +----------+-----------------+
+              |
+              V
+   +---------------------+
+   |    ApplyActions     |
+   |    (tuneSignal)     |
+   +---------------------+
+```
 
 ---
 
@@ -1183,4 +1246,3 @@ For questions, suggestions, or contributions, feel free to reach out:
 This project is licensed under the BSD 3-Clause Clear License.
 
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