Readdir rm -rf graphs

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<pre>
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    36: Linux 2.6.36
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36NORC: Linux 2.6.36 (without readdir cap)
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    38: Linux 2.6.38
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  38RC: Linux 2.6.38 (with readdir cap added back)
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  38NB: Linux 2.6.38 (with Neil Brown's patch and loop detection)
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</pre>
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== Real ==
== Real ==
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=== NFS v3 ===
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* [[File:v3_rm_rf_noplus_real.jpg]]
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** Without readdir plus, an unmodified 2.6.38 kernel takes longer to remove a large directory than the other kernels
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* [[File:v3_rm_rf_plus_real.jpg]]
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** Using readdir plus removes large directories faster than using a simple readdir.
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=== NFS v4 ===
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* [[File:v4_rm_rf_noplus_real.jpg]]
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** Kernels perform the same without readdir plus
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* [[File:v4_rm_rf_plus_real.jpg]]
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** With readdir plus enabled, the kernels take about the same amount of time to remove the directory.
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== Sys ==
== Sys ==
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=== NFS v3 ===
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* [[File:v3_rm_rf_noplus_sys.jpg]]
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** The command takes about the same amount of kernel time for each tested kernel.
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* [[File:v3_rm_rf_plus_sys.jpg]]
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* Using readdir plus decreases the kernel time needed to complete the command
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=== NFS v4 ===
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* [[File:v4_rm_rf_noplus_sys.jpg]]
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** Tested kernels use about the same amount of kernel time to complete the command.
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* [[File:v4_rm_rf_plus_sys.jpg]]
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** 2.6.36 kernels use less kernel time than 2.6.38 kernels.
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== RPC ops ==
== RPC ops ==
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=== NFS v3 ===
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* [[File:v3_rm_rf_noplus_rpc.jpg]]
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** The tested kernels use about the same number of RPC operations.
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* [[File:v3_rm_rf_plus_rpc.jpg]]
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** Using readdir plus results in fewer RPC operations to remove the directory
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=== NFS v4 ===
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* [[File:v4_rm_rf_noplus_rpc.jpg]]
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** All tested kernels issue the same number of RPC operations to remove directories
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* [[File:v4_rm_rf_plus_rpc.jpg]]
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** All tested kernels issue almost the same number of RPC operations to remove directories

Latest revision as of 18:42, 7 April 2011

    36: Linux 2.6.36
36NORC: Linux 2.6.36 (without readdir cap)
    38: Linux 2.6.38
  38RC: Linux 2.6.38 (with readdir cap added back)
  38NB: Linux 2.6.38 (with Neil Brown's patch and loop detection)

Contents

Real

NFS v3

  • V3 rm rf noplus real.jpg
    • Without readdir plus, an unmodified 2.6.38 kernel takes longer to remove a large directory than the other kernels
  • V3 rm rf plus real.jpg
    • Using readdir plus removes large directories faster than using a simple readdir.

NFS v4

  • V4 rm rf noplus real.jpg
    • Kernels perform the same without readdir plus
  • V4 rm rf plus real.jpg
    • With readdir plus enabled, the kernels take about the same amount of time to remove the directory.

Sys

NFS v3

  • V3 rm rf noplus sys.jpg
    • The command takes about the same amount of kernel time for each tested kernel.
  • V3 rm rf plus sys.jpg
  • Using readdir plus decreases the kernel time needed to complete the command

NFS v4

  • V4 rm rf noplus sys.jpg
    • Tested kernels use about the same amount of kernel time to complete the command.
  • V4 rm rf plus sys.jpg
    • 2.6.36 kernels use less kernel time than 2.6.38 kernels.

RPC ops

NFS v3

  • V3 rm rf noplus rpc.jpg
    • The tested kernels use about the same number of RPC operations.
  • V3 rm rf plus rpc.jpg
    • Using readdir plus results in fewer RPC operations to remove the directory

NFS v4

  • V4 rm rf noplus rpc.jpg
    • All tested kernels issue the same number of RPC operations to remove directories
  • V4 rm rf plus rpc.jpg
    • All tested kernels issue almost the same number of RPC operations to remove directories
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