On 22-Oct-18 10:08 PM, Avinash Chaurasia wrote:
Hello,
I am not sure whether this is right list for posting this problem. I am
trying to understand how dpdk allocate memory. I tried digging code to
understand memory allocation of DPDK. So far I understood that memory is
allocated from a heap that dpdk maintains. However, this heap must be
allocated at some place. I failed to traceback any function (called from
heap_alloc()) that calls mmap to allocate memory. Please let me know when
this heap is created, which function call does that.
Thanks
Avinash
Hi Avinash,
Here's a very high level overview.
At initialization, we mmap() anonymous memory regions (eal_memory.c
contains the code - both for legacy and non-legacy mode). Then, we map
actual pages into that space either at init (in legacy mode) or as
needed (in non-legacy mode).
In legacy mode, pages are mapped into anonymous memory straight away
(see legacy init code in eal_memory.c). For non-legacy, page allocation
happens in eal_memalloc.c on request from malloc (see malloc_heap.c). In
both cases, newly allocated pages are added to DPDK heap, and from there
they can be used by the rest of DPDK using rte_malloc or
rte_memzone_reserve API's.
--
Thanks,
Anatoly
