Microsoft-Windows-MMCSS

Event	Title	Channel	Sample	Rule
1	Thread priority of.	Operational	N	N
2	Scheduler woke up for reason Reason.	Operational	N	N
3	Scheduler thread slept.	Operational	N	N
5	MMCSS Service started.	Operational	N	N
6	MMCSS Service stopped.	Operational	N	N
7	Thread joined MMCSS Task TaskName.	Operational	N	N
8	Thread left MMCSS	Operational	N	N
12	TaskIndex TaskIndex yielded for Duration hectons.	Operational	N	N
13	TaskIndex TaskIndex canceled a registered yield.	Operational	N	N
14	TaskIndex TaskIndex sets multimedia mode to ThreadTag.	Operational	N	N
15	TaskIndex TaskIndex deadline Expired.	Operational	N	N
16	Notify Power Manger to engage turbo mode (TurboEngaged).	Operational	N	N
17	Thread Buffering Start (ThreadID).	Operational	N	N
18	Thread Buffering Stop (ThreadID).	Operational	N	N
19	TaskIndex TaskIndex predeadline Expired.	Operational	N	N
20	Thread joined MMCSS TaskIndex TaskIndex TaskName1 TaskName1 TaskName2 TaskName2.	Operational	N	N

Event ID 1: Thread priority of.

Channel: Operational
Task: Scheduler_Priority_Change

Description

Thread priority of (ProcessID.ThreadID) in task TaskIndex has changed to Priority.

Message #

Thread priority of (%1.%2) in task %4 has changed to %3.

Fields #

Name	Description
`ProcessID` UInt32
`ThreadID` UInt32
`Priority` UInt8
`TaskIndex` UInt32

Event ID 2: Scheduler woke up for reason Reason.

Channel: Operational
Task: Scheduler_Wakeup

Message #

Scheduler woke up for reason %1.

Fields #

Name	Description
`Reason` UInt32

Event ID 3: Scheduler thread slept.

Channel: Operational
Task: Scheduler_Sleep

Fields #

Name	Description
`Reason` UInt32
`Duration` UInt32

Event ID 5: MMCSS Service started.

Channel: Operational
Task: Service_Start

Event ID 6: MMCSS Service stopped.

Channel: Operational
Task: Service_Stop

Event ID 7: Thread joined MMCSS Task TaskName.

Channel: Operational
Task: Thread_Join

Message #

Thread joined MMCSS Task %5

Fields #

Name	Description
`ThreadID` UInt32
`MediumPriority` UInt8
`LowPriority` UInt8
`UberLowPriority` UInt8
`TaskName` UnicodeString
`TaskIndex` UInt32
`Category` UInt8
`Flags` UInt8

Event ID 8: Thread left MMCSS

Channel: Operational
Task: Thread_Leave

Fields #

Name	Description
`ThreadID` UInt32
`OriginalBasePriority` UInt8

Event ID 12: TaskIndex TaskIndex yielded for Duration hectons.

Channel: Operational
Task: TaskIndex_Yield

Message #

TaskIndex %1 yielded for %2 hectons

Fields #

Name	Description
`TaskIndex` UInt32
`Duration` UInt32
`PreDuration` UInt32

Event ID 13: TaskIndex TaskIndex canceled a registered yield.

Channel: Operational
Task: TaskIndex_YieldCancel

Message #

TaskIndex %1 canceled a registered yield

Fields #

Name	Description
`TaskIndex` UInt32

Event ID 14: TaskIndex TaskIndex sets multimedia mode to ThreadTag.

Channel: Operational
Task: Set_MultimediaMode

Message #

TaskIndex %1 sets multimedia mode to %2

Fields #

Name	Description
`TaskIndex` UInt32
`ThreadTag` UInt32

Event ID 15: TaskIndex TaskIndex deadline Expired.

Channel: Operational
Task: TaskIndex_DeadlineExpired

Message #

TaskIndex %1 deadline Expired

Fields #

Name	Description
`TaskIndex` UInt32

Event ID 16: Notify Power Manger to engage turbo mode (TurboEngaged).

Channel: Operational
Task: TurboEngaged

Message #

Notify Power Manger to engage turbo mode (%1)

Fields #

Name	Description
`TurboEngaged` UInt32

Event ID 17: Thread Buffering Start (ThreadID).

Channel: Operational
Task: ThreadBuffering
Opcode: Start

Message #

Thread Buffering Start (%1)

Fields #

Name	Description
`ThreadID` UInt32

Event ID 18: Thread Buffering Stop (ThreadID).

Channel: Operational
Task: ThreadBuffering
Opcode: Stop

Message #

Thread Buffering Stop (%1)

Fields #

Name	Description
`ThreadID` UInt32

Event ID 19: TaskIndex TaskIndex predeadline Expired.

Channel: Operational
Task: TaskIndex_PreDeadlineExpired

Message #

TaskIndex %1 predeadline Expired

Fields #

Name	Description
`TaskIndex` UInt32

Event ID 20: Thread joined MMCSS TaskIndex TaskIndex TaskName1 TaskName1 TaskName2 TaskName2.

Channel: Operational
Task: Thread_SetChars

Message #

Thread joined MMCSS TaskIndex %1 TaskName1 %2 TaskName2 %3

Fields #

Name	Description
`TaskIndex` UInt32
`TaskName1` UnicodeString
`TaskName2` UnicodeString

Provenance

ETW provider GUID 36008301-e154-466c-acec-5f4cbd6b4694

Defined in avrt.dll, which carries the event manifest.

WS2022-20348.4893, schema read from the registered manifest, binary version 10.0.20348.1, captured 2026-06-02 — Manifest XML pack, 1.9 MB
Win11-26200.6584, schema read from the registered manifest, binary version 10.0.26100.1, captured 2026-06-02 — Manifest XML pack, 2.0 MB