[dpdk-dev] [PATCH v7 0/3] run-time Linking support

Xiaoyun Li xiaoyun.li at intel.com
Thu Oct 5 14:33:11 CEST 2017

This patchset dynamically selects functions at run-time based on CPU flags
that current machine supports.This patchset modifies mempcy, memcpy perf
test and x86 EFD, using function pointers and bind them at constructor time.
Then in the cloud environment, users can compiler once for the minimum target
such as 'haswell'(not 'native') and run on different platforms (equal or above
haswell) and can get ISA optimization based on running CPU.

Xiaoyun Li (3):
  eal/x86: run-time dispatch over memcpy
  app/test: run-time dispatch over memcpy perf test
  efd: run-time dispatch over x86 EFD functions

* Use gcc function multi-versioning to avoid compilation issues.
* Add macros for AVX512 and AVX2. Only if users enable AVX512 and the compiler
supports it, the AVX512 codes would be compiled. Only if the compiler supports
AVX2, the AVX2 codes would be compiled.

* Reduce function calls via only keep rte_memcpy_xxx.
* Add conditions that when copy size is small, use inline code path.
Otherwise, use dynamic code path.
* To support attribute target, clang version must be greater than 3.7.
Otherwise, would choose SSE/AVX code path, the same as before.
* Move two mocro functions to the top of the code since they would be used in
inline SSE/AVX and dynamic SSE/AVX codes.

* Modify rte_memcpy.h to several .c files and modify makefiles to compile
AVX2 and AVX512 files.

* Delete redundant repeated codes of rte_memcpy_xxx.
* Modify makefiles to enable reuse of existing rte_memcpy.
* Delete redundant codes of rte_efd_x86.h in v4. Move it into .c file and enable
compilation -mavx2 for it in makefile since it is already chosen at run-time.

* Fix shared target build failure.
* Safely remove redundant efd x86 avx2 codes since the file is compiled
with -mavx2.

* Modify the added version map code in v6 to be more reasonable.
* Safely remove redundant efd x86 avx2 codes since the file is compiled
with -mavx2.

 lib/librte_eal/bsdapp/eal/Makefile                 |  19 +
 lib/librte_eal/bsdapp/eal/rte_eal_version.map      |   7 +
 .../common/include/arch/x86/rte_memcpy.c           |  59 ++
 .../common/include/arch/x86/rte_memcpy.h           | 861 +------------------
 .../common/include/arch/x86/rte_memcpy_avx2.c      |  44 +
 .../common/include/arch/x86/rte_memcpy_avx512f.c   |  44 +
 .../common/include/arch/x86/rte_memcpy_internal.h  | 909 +++++++++++++++++++++
 .../common/include/arch/x86/rte_memcpy_sse.c       |  40 +
 lib/librte_eal/linuxapp/eal/Makefile               |  19 +
 lib/librte_eal/linuxapp/eal/rte_eal_version.map    |   7 +
 lib/librte_efd/Makefile                            |   6 +
 lib/librte_efd/rte_efd_x86.c                       |  77 ++
 lib/librte_efd/rte_efd_x86.h                       |  48 +-
 mk/rte.cpuflags.mk                                 |  14 +
 test/test/test_memcpy_perf.c                       |  40 +-
 15 files changed, 1289 insertions(+), 905 deletions(-)
 create mode 100644 lib/librte_eal/common/include/arch/x86/rte_memcpy.c
 create mode 100644 lib/librte_eal/common/include/arch/x86/rte_memcpy_avx2.c
 create mode 100644 lib/librte_eal/common/include/arch/x86/rte_memcpy_avx512f.c
 create mode 100644 lib/librte_eal/common/include/arch/x86/rte_memcpy_internal.h
 create mode 100644 lib/librte_eal/common/include/arch/x86/rte_memcpy_sse.c
 create mode 100644 lib/librte_efd/rte_efd_x86.c


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