IV72873: MAX SGE LIMIT EXCEEDED EXCEPTION EVEN IF IT HAS NOT REALLY EXCEE DED

APAR status

• Closed as program error.

Error description

• Error Message: We get below exception, when we try to send more
  than number of max sge, work requests with 1 sge each. (ie)
  Assume number of sge allocated for QP is 4 and WR is 100 when we
  try to send 50 work requests with one sge each will result in
  below exception. max sge should not aggregate all WR's SGEs. It
  is per work request number.Exception in thread "main"
  java.io.IOException: QueuePair Limit exceeded for number of
  sgeat
  com.ibm.net.rdma.jverbs.verbs.NativePostReceiveMethod.<init>(Nat
  ivePostReceiveMethod.java:83)at
  com.ibm.net.rdma.jverbs.verbs.NativeRdmaJVerbs.preparePostReceiv
  e(NativeRdmaJVerbs.java:168)at
  com.ibm.net.rdma.jverbs.verbs.QueuePair.preparePostReceive(Queue
  Pair.java:208)at CustomEndpoint.init(CustomEndpoint.java:91)at
  com.ibm.net.rdma.jverbs.endpoints.RdmaEndpoint.allocateResources
  (RdmaEndpoint.java:193)at
  com.ibm.net.rdma.jverbs.endpoints.RdmaEndpointGroup.allocateReso
  urces(RdmaEndpointGroup.java:151)at
  com.ibm.net.rdma.jverbs.endpoints.RdmaEndpointGroup.allocateReso
  urcesRaw(RdmaEndpointGroup.java:196)at
  com.ibm.net.rdma.jverbs.endpoints.RdmaEndpoint.connect(RdmaEndpo
  int.java:131)at
  EndpointJverbsClient.start(EndpointJverbsClient.java:53)at
  EndpointJverbsClient.main(EndpointJverbsClient.java:74)
  .
  Stack Trace: N/A
  .
  

Local fix

• NA
  

Problem summary

• We are considering cumulative number of sge across work request
  and compare against the device max sge. But device max sge means
  max sges per work request. Now corrected the assumption. Fix is
  in both post send and post receive.
  

Problem conclusion

• Fixed the assumption by doing the right check
  .
  This APAR will be fixed in the following Java Releases:
     8    SR1 FP10  (8.0.1.10)
     7 R1 SR3 FP10  (7.1.3.10)
     7    SR9 FP 10 (7.0.9.10)
  .
  Contact your IBM Product's Service Team for these Service
  Refreshes and Fix Packs.
  For those running stand-alone, information about the available
  Service Refreshes and Fix Packs can be found at:
             https://www.ibm.com/developerworks/java/jdk/
  

Temporary fix

Comments

APAR Information

• APAR is sysrouted FROM one or more of the following:

• APAR is sysrouted TO one or more of the following:

Fix information

• Fixed component name

  JAVA CLASS LIBS

• Fixed component ID

  620700130

Applicable component levels

• R800 PSY

     UP

• R700 PSY

     UP