Profiling in memory part is hard to be accurate because of BPF infrastructure.
memleak keeps misjudging memory leak on the complicated environment which has
the action of free in hard/soft irq.

For example, in my misjudged case:

640 bytes in 10 allocations from stack
--
__kmalloc+0x178 [kernel]
__kmalloc+0x178 [kernel]
xhci_urb_enqueue+0x140 [kernel]
usb_hcd_submit_urb+0x5e0 [kernel]

This result looks like kernel doesn't free urb_priv. However, it's not true.
The reason for this leak is because xhci hw irq interrupts during the BPF program.
BPF program is not finished on that CPU, and xhci_irq() will call xhci_urb_free_priv()
before the end. But the kernel doesn't permit this isr to go into BPF program again.
Because BPF infrastructure(trace_call_bpf) denied this action.
So we miss this free action and cause memory leak misjudgment.

Side-effect:
- Increase overhead for each memory allocation.
- A higher chance to be interrupted at the allocation part causes ignore more allocations.

This workaround doesn't solve all misjudgments, the improvement in BPF infrastructure
is the only solution.