Timing comparisons for multi-kprobe feature

[Hien Nguyen]

BTW, my machine is a 4 way 700Mhz pentium III

And the same go for  multi-probe test,  here a portion of the output for 
multi-probe test (1 microsecond)

Apr 18 14:58:46 elm3b99 kernel: kprobe overhead of 10 cycles per iteration
Apr 18 14:58:46 elm3b99 kernel: PASSED: for 5
Apr 18 14:58:46 elm3b99 kernel: kprobe start 2666398510855, stop 
2666398521721
Apr 18 14:58:46 elm3b99 kernel: kprobe overhead count 10, number of 
cycles 10866
Apr 18 14:58:46 elm3b99 kernel: kprobe overhead of 1086 cycles per iteration
Apr 18 14:58:46 elm3b99 kernel: kprobe start 2666398548107, stop 
2666398558376
Apr 18 14:58:46 elm3b99 kernel: kprobe overhead count 10, number of 
cycles 10269
Apr 18 14:58:46 elm3b99 kernel: kprobe overhead of 1026 cycles per iteration
Apr 18 14:58:46 elm3b99 kernel: kprobe start 2666398583828, stop 
2666398594476
Apr 18 14:58:46 elm3b99 kernel: kprobe overhead count 10, number of 
cycles 10648
Apr 18 14:58:46 elm3b99 kernel: kprobe overhead of 1064 cycles per iteration
Apr 18 14:58:46 elm3b99 kernel: kprobe start 2666398623607, stop 
2666398623801
Apr 18 14:58:47 elm3b99 kernel: kprobe overhead count 10, number of 
cycles 194
Apr 18 14:58:47 elm3b99 kernel: kprobe overhead of 19 cycles per iteration
Apr 18 14:58:47 elm3b99 kernel: kprobe start 2666398659568, stop 
2666398659686
Apr 18 14:58:47 elm3b99 kernel: kprobe overhead count 10, number of 
cycles 118
Apr 18 14:58:47 elm3b99 kernel: kprobe overhead of 11 cycles per iteration
Apr 18 14:58:47 elm3b99 kernel: kprobe start 2666398683675, stop 
2666398683779
Apr 18 14:58:47 elm3b99 kernel: kprobe overhead count 10, number of 
cycles 104
Apr 18 14:58:47 elm3b99 kernel: kprobe overhead of 10 cycles per iteration
Apr 18 14:58:47 elm3b99 kernel: PASSED: for 6
Apr 18 14:58:47 elm3b99 kernel: kprobe start 2666398721825, stop 
2666398733128


Hien Nguyen wrote:

> Hi Ananth, Will,
>
> I can't explain this but this the output for my timing_kprobe, which 
> my calculation yeilds 1 for both kprobe and jprobe
>
> Apr 18 15:58:02 elm3b99 kernel: kprobe registered
> Apr 18 15:58:02 elm3b99 kernel: plant jprobe at f8a002b0, handler addr 
> f8a00030
> Apr 18 15:58:12 elm3b99 kernel: kprobe start 5169729839300, stop 
> 5170565252311
> Apr 18 15:58:12 elm3b99 kernel: kprobe overhead count 1000000, number 
> of cycles 835413011
> Apr 18 15:58:14 elm3b99 kernel: jprobe start 5170565271260, stop 
> 5171945384508
> Apr 18 15:58:14 elm3b99 kernel: jprobe overhead count 1000000, number 
> of cycles 1380113248
> Apr 18 15:58:15 elm3b99 kernel: kprobe start 5171945399260, stop 
> 5172780564338
> Apr 18 15:58:15 elm3b99 kernel: kprobe overhead count 1000000, number 
> of cycles 835165078
> Apr 18 15:58:17 elm3b99 kernel: jprobe start 5172780578137, stop 
> 5174156636912
> Apr 18 15:58:17 elm3b99 kernel: jprobe overhead count 1000000, number 
> of cycles 1376058775
> Apr 18 15:58:17 elm3b99 kernel: kprobe unregistered
> Apr 18 15:58:17 elm3b99 kernel: jprobe unregistered
>
>
> Ananth N Mavinakayanahalli wrote:
>
>> Hi,
>>
>> Here is the result of the tests I carried out to determine the cost
>> of the multiple-kprobes feature. All tests were carried out on a
>> uni PIII running at 732MHz.
>>
>> I used Will's timing_kprobe and kprobe_multi modules on linux-2.6.12-rc2
>> for the tests.
>>
>> (All values in microseconds)
>>
>>         Vanilla        Single        Multiple
>>         (2.6.12-rc2)    Interface    Interfaces
>> ------------------------------------------------------------
>> kprobe        1.124        1.149        1.149
>> jprobe        1.891        1.885        1.885
>> kprobe_multi    NA        1.306        1.387
>>
>> Note:
>> - Single Interface => linux-2.6.12-rc2 + take3 patch
>> - Multiple Interfaces => linux-2.6.12-rc2 + take4 patch
>> - kprobe_multi => averaged values with Will's kprobe_multi testcase
>>
>> Thanks,
>> Ananth
>>
>
>