question on system tap

[Hebenstreit, Michael]

my problem was analysing the behaviour of the Lustre file system. I'm NOT a kernel programmer, though I know quite a bit about it. What I like to do is
 
a) I start with instrumenting a kernel function A
b) I run my benchmark
c) the output should tell me which functions were CALLED by A and the timestamp when they return to A
d) for those function that interest me more I repeat this procedure
 
this way my instrumentation is kept light; I could not find any way to do this with systemtap (maybe a different tool would be better?)
 
the original problem btw was a drop in the Lustre file system performance by 20% when switching from RH5.3 kernel to RH 5.4 kernel. With the methodology described I could have found that a different function tree was traversed in in RH5.4, and where the timinig differences occured
 
thanks for insight
Michael
 
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Michael Hebenstreit                 Senior Cluster Architect
Intel Corporation                   Software and Services Group/DRD
2800 N Center Dr, DP3-307           Tel.:   +1 253 371 3144
WA 98327, DuPont           
UNITED STATES                       E-mail: michael.hebenstreit@intel.com