IBM Support

IJ21127: NMI WATCHDOG: BUG: SOFT LOCKUP - CPU STUCK [NFSD]

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APAR status

  • Closed as program error.

Error description

  • On RHEL 7 nodes (pre-Linux kernel v3.18), in the Spectrum
Scale kernel NFS support environment, Spectrum Scale may
try to acquire some mutex, while holding an inode spin
lock
which may be detected as a soft lockup issue by the
kernel
NMI watchdog.

Local fix

  • 



Problem summary


    

  •  n RHEL 7 nodes (pre-Linux kernel v3.18), in the GPFS kernel NFS
 support

environment, GPFS may try to acquire some mutex, while holding
an inode

spin lock, which may be detected as a soft lockup issue by the
kernel NMI watchdog.

    



Problem conclusion


    

  • Benefits of the solution, in customer terms:

Avoid CPU stuck and performance impacts

Work around:

None

Problem trigger:

GPFS breaks a spin lock holding policy in NFS support
environment

Symptom:

Performance Impact/CPU stuck

Platforms affected:

All RHEL 7.x

Functional Area affected:

Users of KNFS/CNFS only

Customer Impact:

High Importance

    



Temporary fix


    

  • 



Comments


    

  • 



APAR Information




    

  • APAR number
    IJ21127
    • 

  • Reported component name
    SPECTRUM SCALE
    • 

  • Reported component ID
    5725Q01AP
    • 

  • Reported release
    423
    • 

  • Status
    CLOSED  PER
    • 

  • PE
    NoPE
    • 

  • HIPER
    NoHIPER
    • 

  • Special Attention
    NoSpecatt / Xsystem
    • 

  • Submitted date
    2019-11-21
    • 

  • Closed date
    2019-12-04
    • 

  • Last modified date
    2019-12-04
    • 





    

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

    • 

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

    
IJ21396
    

    • 



Fix information


    

  • Fixed component name
    SPECTRUM SCALE
    • 

  • Fixed component ID
    5725Q01AP
    • 



Applicable component levels


    








      
              
                            

              

              [{"Business Unit":{"code":"BU058","label":"IBM Infrastructure w\/TPS"},"Product":{"code":"STXKQY","label":"IBM Spectrum Scale"},"Component":"","ARM Category":[],"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"423","Edition":"","Line of Business":{"code":"LOB26","label":"Storage"}},{"Business Unit":{"code":"BU058","label":"IBM Infrastructure w\/TPS"},"Product":{"code":"SSFKCN","label":"General Parallel File System"},"Component":"","ARM Category":[],"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"423","Edition":"","Line of Business":{"code":"","label":""}}]
              

                                                                    

          
 
        

      

    

      

        

          

            
Document Information


            

            


                        

            Modified date:
            

            04 December 2019
            

            
                      

        


        

        


      

    

  



    

  

  
    
            

          
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