RFR: Allocation latency tracing

[Roman Kennke]

Am 24.08.2017 um 16:28 schrieb Aleksey Shipilev:
> On 08/24/2017 04:18 PM, Aleksey Shipilev wrote:
>> Hi,
>>
>> Before we go into refactoring the allocation slow-paths, we need something that will tell the
>> latency we have there. For example:
>>   http://cr.openjdk.java.net/~shade/shenandoah/stats-alloc/webrev.01/
> Updated:
>   http://cr.openjdk.java.net/~shade/shenandoah/stats-alloc/webrev.02/
>
> Moved new code to shenandoahUtils.cpp.
>
> Thanks,
> -Aleksey
>
That sounds very useful.

I wonder if the tracing should be moved to the single place where we do
allocations (allocate_memory() ) instead of scattering around to all the
callers (mem_allocate(), allocate_new_tlab(), allocate_new_gclab() etc) ?

In the long term (not this patch) all alloc-related code should be moved
to a separate class, either ShenandoahAlloc or even just ShenandoahFreeSet.

Roman