[dpdk-dev] [RFC v6 0/6] lib/ring: APIs to support custom element size
Honnappa Nagarahalli
honnappa.nagarahalli at arm.com
Mon Oct 21 02:22:54 CEST 2019
The current rte_ring hard-codes the type of the ring element to 'void *',
hence the size of the element is hard-coded to 32b/64b. Since the ring
element type is not an input to rte_ring APIs, it results in couple
of issues:
1) If an application requires to store an element which is not 64b, it
needs to write its own ring APIs similar to rte_event_ring APIs. This
creates additional burden on the programmers, who end up making
work-arounds and often waste memory.
2) If there are multiple libraries that store elements of the same
type, currently they would have to write their own rte_ring APIs. This
results in code duplication.
This patch adds new APIs to support configurable ring element size.
The APIs support custom element sizes by allowing to define the ring
element to be a multiple of 32b.
The aim is to achieve same performance as the existing ring
implementation. The patch adds same performance tests that are run
for existing APIs. This allows for performance comparison.
I also tested with memcpy. x86 shows significant improvements on bulk
and burst tests. On the Arm platform, I used, there is a drop of
4% to 6% in few tests. May be this is something that we can explore
later.
Note that this version skips changes to other libraries as I would
like to get an agreement on the implementation from the community.
They will be added once there is agreement on the rte_ring changes.
v6
- Labelled as RFC to indicate the better status
- Added unit tests to test the rte_ring_xxx_elem APIs
- Corrected 'macro based partial memcpy' (5/6) patch
- Added Konstantin's method after correction (6/6)
- Check Patch shows significant warnings and errors mainly due
copying code from existing test cases. None of them are harmful.
I will fix them once we have an agreement.
v5
- Use memcpy for chunks of 32B (Konstantin).
- Both 'ring_perf_autotest' and 'ring_perf_elem_autotest' are available
to compare the results easily.
- Copying without memcpy is also available in 1/3, if anyone wants to
experiment on their platform.
- Added other platform owners to test on their respective platforms.
v4
- Few fixes after more performance testing
v3
- Removed macro-fest and used inline functions
(Stephen, Bruce)
v2
- Change Event Ring implementation to use ring templates
(Jerin, Pavan)
Honnappa Nagarahalli (6):
test/ring: use division for cycle count calculation
lib/ring: apis to support configurable element size
test/ring: add functional tests for configurable element size ring
test/ring: add perf tests for configurable element size ring
lib/ring: copy ring elements using memcpy partially
lib/ring: improved copy function to copy ring elements
app/test/Makefile | 2 +
app/test/meson.build | 2 +
app/test/test_ring_elem.c | 859 +++++++++++++++++++++++++++
app/test/test_ring_perf.c | 22 +-
app/test/test_ring_perf_elem.c | 419 +++++++++++++
lib/librte_ring/Makefile | 3 +-
lib/librte_ring/meson.build | 4 +
lib/librte_ring/rte_ring.c | 34 +-
lib/librte_ring/rte_ring.h | 1 +
lib/librte_ring/rte_ring_elem.h | 818 +++++++++++++++++++++++++
lib/librte_ring/rte_ring_version.map | 2 +
11 files changed, 2147 insertions(+), 19 deletions(-)
create mode 100644 app/test/test_ring_elem.c
create mode 100644 app/test/test_ring_perf_elem.c
create mode 100644 lib/librte_ring/rte_ring_elem.h
--
2.17.1
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