function::qsq_wait_time - Linux

Overview

qsq_wait_time is a command in Linux used to set or display the approximate amount of time a request should wait before being considered timed out. It is used with the Linux kernel’s software queuing (SQ) subsystem.

Syntax

qsq_wait_time [devpath] [subsys] [wait_time]

where:

  • devpath: The path to the SQ device, such as /sys/devices/platform/soc/1d84000.sq/
  • subsys: The subsystem name, such as "dma_requests"
  • wait_time: The wait time in microseconds. A value of 0 disables the timeout.

Options/Flags

None

Examples

Display the current wait time:

qsq_wait_time /sys/devices/platform/soc/1d84000.sq dma_requests

Change the wait time:

qsq_wait_time /sys/devices/platform/soc/1d84000.sq dma_requests 100000

Common Issues

  • Error message: "No such device or directory"
    • Solution: Ensure that the provided devpath is correct.
  • No change in behavior:
    • Solution: Ensure that the file permissions allow writing to the sysfs entry.

Integration

qsq_wait_time can be used in conjunction with other commands to manage SQ device behavior. For example, qsq_status can be used to display the current status of requests in the queue.

Related Commands

  • qsq_status: Shows the status of requests in an SQ queue
  • qsq_mem: Displays memory usage information for the SQ subsystem

Additional Resources: