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Resolving mutex wait states?

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The Question is:

We have a number of processes that go into the
MUTEX state for a number of minutes.  Can
you list the steps that we would follow to
determine why that process is in MUTEX?

The Answer is :

  Please acquire and read the OpenVMS Internals and Data Structures Manual
  for an introduction to and the details of the MUTEX state -- there are
  three or four pages on this topic in the IDSM.
  The key is usually the value in the PCB$L_EFWM field.  Small values are
  determined based on the contents of RSNDEF.  Large (negative) values
  will indicate process quotas, and the contents of PCB$L_EFWM will point
  to the process JIB.  In the JIB$B_FLAGS, bit 0 indicates a wait because
  of insufficient BYTCNT, and bit 1 indicates an insufficient TQE setting.
  DECamds can often be useful for examining and even for clearing these.
  DECamds is licensed with OpenVMS Cluster license in earlier versions,
  and with the base OpenVMS license in more recent versions.
  Related topics here in Ask The Wizard include (6), (2347), (5841),
  and (7120).

answer written or last revised on ( 3-OCT-2001 )

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