Table of Contents

Introduction

This document is related to epic WPERF-25 - Getting issue details... STATUS which covers various issues around wperf-driver improvements.

Add new "busy" state to wperf-driver

See WPERF-116 - Getting issue details... STATUS for more Jira related information about this feature.

Required bahaviour

1. Ultimatelly remove the call to WdfDeviceInitSetExclusive.

2. Create a persistent structure inside wperf-driver that capture driver’s “transition” current state, like if it is sampling, counting, if PMU resources are available or not. We want to capture:

   1. [bool flag] If driver is currently “counting” or “sampling” - this will set BUSY state to true.

   2. [IOCTL request no.] Current IOCTL being processed - this is useful to determine in user space if we are actually counting/timeline or sampling or doing some other work.

3. How IOCTL will set BUSY state?

   1. Some IOCTL will set (and clear after IOCTL is finished) busy state during IOCTL handling only, e.g. PMU_CTL_RESET or IOCTL_PMU_CTL_QUERY_HW_CFG. This is because these “transactions” are pending during IOCTL handle and end after.

   2. Some IOCTLs will set BUSY state

   3. Not all IOCTLs may set bus state as some do not “set in motion” the driver.

4. Update to driver ↔︎ user-space protocol.

   1. We will send to user-space new set of flags: BUSY flag and at least info about which IOCTL is ongoing.

      1. If BUSY state is true: IOCTL field is valid with IOCTL being processed now.

List of IOCTLs and BUSY state

<>