Re:Re: [PATCH] Add accumulated call counter for memory allocation profiling

[David Wang]

HI Suren, 

At 2024-07-01 03:33:14, "Suren Baghdasaryan" <surenb@xxxxxxxxxx> wrote:
>On Mon, Jun 17, 2024 at 8:33 AM David Wang <00107082@xxxxxxx> wrote:
>>
>> Accumulated call counter can be used to evaluate rate
>> of memory allocation via delta(counters)/delta(time).
>> This metrics can help analysis performance behaviours,
>> e.g. tuning cache size, etc.
>
>Sorry for the delay, David.
>IIUC with this counter you can identify the number of allocations ever
>made from a specific code location. Could you please clarify the usage
>a bit more? Is the goal to see which locations are the most active and
>the rate at which allocations are made there? How will that
>information be used?
 
Cumulative counters can be sampled with timestamp,  say at T1, a monitoring tool got a sample value V1,
then after sampling interval, at T2,  got a sample value V2. Then the average rate of allocation can be evaluated
via (V2-V1)/(T2-T1). (The accuracy depends on sampling interval)

This information "may" help identify where the memory allocation is unnecessary frequent,  
and  gain some  better performance by making less memory allocation .
The performance "gain" is just a guess, I do not have a valid example.



>I'm a bit cautious here because each counter will take more space and
>use some additional cpu cycles.
>Thanks,
>Suren.
>



Thanks~!
David