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IZ91123: TCP_NODELAYACK CAUSES EAGAIN ERROR ON SORECEIVE APPLIES TO AIX 5300-12

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APAR status

  • Closed as program error.

Error description

  • If tcp_nodelayack is set on each end of 2 socket pair, it
could lead to a spurious sorwakeup when a socket is not
readable, causing the next read on the socket to return
EAGAIN.
This is especially true if the socket pair are using the
loopback
 interface.

Local fix

  • disable tcp_nodelayack

Problem summary

  • pollset_poll returns back to the application with POLLIN,
even though the socket is not readable, causing next
read on the socket to return EAGAIN.

Problem conclusion

  • Code is modified to check if the socket is readable before
awakening the process

Temporary fix

  • 



Comments


    

  • 5300-10 - use AIX APAR IZ91031
5300-11 - use AIX APAR IZ91124
5300-12 - use AIX APAR IZ91123
6100-03 - use AIX APAR IZ94543
6100-04 - use AIX APAR IZ81307
6100-05 - use AIX APAR IZ94530
6100-06 - use AIX APAR IZ85844
7100-00 - use AIX APAR IZ92383

    



APAR Information




    

  • APAR number
    IZ91123
    • 

  • Reported component name
    AIX  5.3
    • 

  • Reported component ID
    5765G0300
    • 

  • Reported release
    530
    • 

  • Status
    CLOSED  PER
    • 

  • PE
    NoPE
    • 

  • HIPER
    NoHIPER
    • 

  • Submitted date
    2010-12-16
    • 

  • Closed date
    2010-12-16
    • 

  • Last modified date
    2013-04-16
    • 





    

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

    
IZ81307
    

    • 

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

    • 



Fix information


    

  • Fixed component name
    AIX  5.3
    • 

  • Fixed component ID
    5765G0300
    • 



Applicable component levels


    

  • R530  PSY  U838600
       UP11/02/22  I  1000
    • 



PTF to Fileset Mapping








      
              
                            

              

              [{"Business Unit":{"code":"BU054","label":"Systems w\/TPS"},"Product":{"code":"SG11P","label":"APARs - AIX 5.3 environment"},"Component":"","ARM Category":[],"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"530","Edition":"","Line of Business":{"code":"","label":""}}]
              

                          

          
 
        

      

    

      

        

          

            
Document Information


            

            


                        

            Modified date:
            

            16 April 2013
            

            
                      

        


        

        


      

    

  



    

  

  
    
            

          
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