Hi Thomas,
On Friday 18 May 2018 06:40 PM, Thomas Monjalon wrote:
Hi,
What is the status of DPDK 18.05 on IBM POWER?
This patch suggests there are some issues but there were no news for
two weeks, after comments from Anatoly.
Are we going to release a DPDK which does not work well on POWER?
This issue is not applicable in v18.05 onwards (due to memory rework
changes there).
Apologies for no update meanwhile, I will check on Anatoly's comments
and get back.
My idea is to address this before next candidate ready on LTS releases
(v17.11, v16.11).
Regards,
Gowrishankar
03/05/2018 12:11, Gowrishankar:
When there are multiple memsegs (each per hugepage), there are couple of
problems observed:
1. Same heap size index is always chosen to add new malloc_elems
again and again, while there is an increasing heap size actually.
Hence, when there is memalloc request for size *more than*
elem->size available in free heap, malloc_heap_alloc would fail.
In elem_start_pt(), we are actually relying on elem->size at the
best, for finding suitable element, which is lower than requested
size, in this case.
Hence, patch 1 in this series addresses this by merging
contiguous malloc_elem (by virt addresses), so that there is
better chance of finding suitable elem for the requested size.
2. Even after resizing the heap malloc_elems, its free_head index
is still the same, as the memsegs are just added in every malloc_
elem. If larger memory is requested in rte_malloc, in a way
that, heap index of requested size is beyond the slot where the
entire heap is available, malloc_heap_alloc would fail.
Because, at the time of heap init, only the lower index is
always chosen to fill up memsegs. Hence, patch 2 addresses this
by moving the list of malloc_elems into new slot in heap, as its
size grows.
We encountered these situations as we run ip_reassembly example app,
when multiple segments are created in VA (when overcommit hugepages set
in powerpc arch).
These problems are found only in the current releases (until v18.05
which carries new implementation for dynamic memory allocation).
These patches are tested with unit tests as well as some of the
examples apps. I request more testing if possible, on other archs
as these are problems in available LTS codes as well.
Signed-off-by: Gowrishankar Muthukrishnan <gowrishanka...@linux.vnet.ibm.com>
