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sys_attrs_rt(5)
NAME
  sys_attrs_rt - rt subsystem attributes

DESCRIPTION
  This reference page lists and describes attributes for the Realtime (rt)
  kernel subsystem. Refer to sys_attrs(5) for an introduction to the topic of
  kernel subsystem attributes.

  Attributes whose names are preceded with an asterisk (*) can be modified
  without rebooting the system.

  aio_listio_max_num
      The maximum number of asynchronous I/O requests supported on the list
      initiated by the lio_listio() function.

      Default: 64 (requests)

      Minimum: 64

      Maximum: 256

  aio_max_percent
      The maximum percentage of physical memory that AIO structures can
      occupy. The value of this attribute is used to scale back
      aio_task_max_num when that is set too high for the system.

      Default: 1 (percent)

      Minimum: 0

      Maximum: 10

      The aio_max_percent attribute is not useful on today's servers, most of
      which have a large amount of memory. Even 1 percent of physical memory
      is too high a limit for many of the servers currently in use.
      Therefore, it is recommended that, if you need to tune any settings
      related to the amount of wired physical memory used for AIO structures,
      it is more practical to use the aio_max_retry, aio_retry_scale, and
      aio_task_max_num attributes.

  aio_max_retry
      The number of additional attempts made on behalf of a process to wire
      AIO buffers to physical memory if the system maximum for wired physical
      memory has already been reached or if the attempt to wire additional
      physical memory would cause that maximum to be exceeded. By default, if
      a process attempts to wire physical memory for AIO buffers and this
      would exceed the system maximum, an error is returned.

      Default: 0 (no retries)

      Minimum: 0

      Maximum: 256

  aio_retry_scale
      The time interval between attempts made for a process to wire AIO
      buffers to physical memory when the system is at its maximum for wired
      physical memory. The time interval is calculated by the following
      formula:

      Hz / aio_retry_scale

      Default: 4 (0.25 seconds when Hz is equal to 1)

      Minimum: 1

      Maximum: 1024

      This attribute has no effect when aio_max_retry is set to 0 (the
      default).

  aio_socket_on_off
      Enables (1) or disables (0) AIO write requests through connected
      sockets.

      Default value: 1 (enabled)

      Do not change the default setting for this attribute unless instructed
      to do so by support personnel or patch kit instructions.

  aio_task_max_num
      A limit that indirectly controls the number of AIO requests that can be
      wired in physical memory by restricting the amount of wired physical
      memory available for a specified number of tasks. One page of wired
      physical memory is available to the number of tasks specified by
      aio_task_max_num.

      Default: 102 (one page of wired memory per 102 tasks)

      Minimum: 0

      Maximum: 2,147,483,647

  rtsem_nsems_max
      This attribute has no effect. It is not currently used by operating
      system software and will be removed in a future release.

  * rttimer_max_num
      The maximum number of POSIX realtime timers per task or process.

      Default: 32 (timers)

      Minimum: 32

      Maximum: 8192

      This attribute can be modified at run time but will affect only the
      processes that start up after the change is made. If you want the
      change to affect a process that is already running, you must stop and
      restart the process.

  sigqueue_max_num
      The maximum number of siginfo structures that can be queued to a
      process.

      Default: 64 (siginfo structures per process)

      Minimum: 0

      Maximum: 32,767

SEE ALSO
  sys_attrs(5)

Index for Section 5

Alphabetical listing for S

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