Querry regarding LTTng instrumentation and timing results on LTTV...

Hi all ,
Iam newbie to LTTng..

i am using genevent-0.31 for instrumenting 2.6.18 kernel to get my root filesystem's 

read performance. I am able to put Marker before the function i am interested to measure 

performance. After collection of data using lttctl, when i am using lttv for graphical display 

i am not able to get any timing information about this particular instrumented function.

i am getting this type of tree structure in LTTV:

in my Traceset :

Traceset statistics

|

-> mode types

|

->MODE_UNKNOWN

->IRQentry

->SOFTIRQ

->SYSCALL

|

->submodes

|

->NONE

->ioctl

->rt_sigaction

->write

->read(statistics for 'read' CPU timr: 0.000423449,elapsed time(

includes perprocess waiting time): 30.967086800, cumulative 

cpu time (includes nested routines and modes); 0.000423449

event count : 443

|

->event_types

|

-> Statistics for 'event_types'

showing the number of events under read like 

syscall_entry: 122

read : 226

....

....

....

myfs_read:1

....

....





my question is why i am not getting the timing information of myfs_read?

and what is the difference between read mentioned under event_types and read under 

submodes below SYSCALL??



REGARDS,

SATISH

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