Readdir rm -rf graphs

From Linux NFS

Revision as of 14:09, 7 April 2011 (view source) Amschuma (Talk | contribs) ← Older edit		Latest revision as of 18:42, 7 April 2011 (view source) Amschuma (Talk | contribs) (→NFS v4)
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	=== NFS v3 ===		=== NFS v3 ===
	* [[File:v3_rm_rf_noplus_real.jpg]]		* [[File: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
	* [[File:v3_rm_rf_plus_real.jpg]]		* [[File:v3_rm_rf_plus_real.jpg]]
		+	** Using readdir plus removes large directories faster than using a simple readdir.
		+
	=== NFS v4 ===		=== NFS v4 ===
	* [[File:v4_rm_rf_noplus_real.jpg]]		* [[File:v4_rm_rf_noplus_real.jpg]]
		+	** Kernels perform the same without readdir plus
	* [[File:v4_rm_rf_plus_real.jpg]]		* [[File:v4_rm_rf_plus_real.jpg]]
		+	** With readdir plus enabled, the kernels take about the same amount of time to remove the directory.
	== Sys ==		== Sys ==
	=== NFS v3 ===		=== NFS v3 ===
	* [[File:v3_rm_rf_noplus_sys.jpg]]		* [[File:v3_rm_rf_noplus_sys.jpg]]
		+	** The command takes about the same amount of kernel time for each tested kernel.
	* [[File:v3_rm_rf_plus_sys.jpg]]		* [[File:v3_rm_rf_plus_sys.jpg]]
		+	* Using readdir plus decreases the kernel time needed to complete the command
		+
	=== NFS v4 ===		=== NFS v4 ===
	* [[File:v4_rm_rf_noplus_sys.jpg]]		* [[File:v4_rm_rf_noplus_sys.jpg]]
		+	** Tested kernels use about the same amount of kernel time to complete the command.
	* [[File:v4_rm_rf_plus_sys.jpg]]		* [[File:v4_rm_rf_plus_sys.jpg]]
		+	** 2.6.36 kernels use less kernel time than 2.6.38 kernels.
	== RPC ops ==		== RPC ops ==
	=== NFS v3 ===		=== NFS v3 ===
	* [[File:v3_rm_rf_noplus_rpc.jpg]]		* [[File:v3_rm_rf_noplus_rpc.jpg]]
		+	** The tested kernels use about the same number of RPC operations.
	* [[File:v3_rm_rf_plus_rpc.jpg]]		* [[File:v3_rm_rf_plus_rpc.jpg]]
		+	** Using readdir plus results in fewer RPC operations to remove the directory
		+
	=== NFS v4 ===		=== NFS v4 ===
	* [[File:v4_rm_rf_noplus_rpc.jpg]]		* [[File:v4_rm_rf_noplus_rpc.jpg]]
		+	** All tested kernels issue the same number of RPC operations to remove directories
	* [[File:v4_rm_rf_plus_rpc.jpg]]		* [[File:v4_rm_rf_plus_rpc.jpg]]
		+	** 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 1 Real 1.1 NFS v3 1.2 NFS v4 2 Sys 2.1 NFS v3 2.2 NFS v4 3 RPC ops 3.1 NFS v3 3.2 NFS v4

Real

NFS v3

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

NFS v4

• 
  • Kernels perform the same without readdir plus
• 
  • With readdir plus enabled, the kernels take about the same amount of time to remove the directory.

Sys

NFS v3

• 
  • The command takes about the same amount of kernel time for each tested kernel.
• 
• Using readdir plus decreases the kernel time needed to complete the command

NFS v4

• 
  • Tested kernels use about the same amount of kernel time to complete the command.
• 
  • 2.6.36 kernels use less kernel time than 2.6.38 kernels.

RPC ops

NFS v3

• 
  • The tested kernels use about the same number of RPC operations.
• 
  • Using readdir plus results in fewer RPC operations to remove the directory

NFS v4

• 
  • All tested kernels issue the same number of RPC operations to remove directories
• 
  • All tested kernels issue almost the same number of RPC operations to remove directories