Re: [1/1][PATCH] nproc v2: netlink access to /proc information

Roger Luethi
2004-09-15T20:04:50Z

Here's another thing we haven't been able to do with /proc: Finding out
the relative cost of computing the elements we offer to user space.

I ran a test program against 2.6.9-rc2-bk1 + nproc to get:

Testing all process fields, best out of 10
FieldID CPU (s) Wall (s) Label
0x03000002 0.140000 0.202728 NOP
0x21000100 0.150000 0.210021 Name
0x22000105 0.120000 0.204886 PID
0x22000109 0.130000 0.205319 UID
0x22000117 0.140000 0.215275 VmSize
0x22000118 0.130000 0.214240 VmLock
0x22000119 0.120000 0.214870 VmRSS
0x22000120 0.160000 1.020574 VmData
0x22000121 0.140000 1.021185 VmStack
0x22000122 0.170000 1.021619 VmExe
0x22000123 0.170000 1.020045 VmLib
0x23000421 0.140000 0.220748 wchan

Ignore the absolute values (I requested each field individually for all
processes on my workstation, 1000 times). The cost of walking all vmas
for VmData & Co. is very visible.

Roger