Tuning-advise for soft-realtime systems

[Clemens Eisserer]

Hello,

I am currently evaluating jemalloc for a soft-realtime system where
worst-case latency is of concern.
When allocating areas of random size honoring the size-distribution
which is to be expected, usually latency is of no concern.
However, from time to time there are latency spikes of ~300
microseconds for a single malloc especially for mid-sized allocations
(e.g. 1024byte).

My guess is those latency spikes arise when jemalloc requests
additional memory for it's arena's from the kernel.
Are there any tuning knobs to reduce the duration of those spikes and
instead increasing there frequency?

Thank you in advance, Clemens