On Tue, 14 Jul 2020 08:31:32 +0100 "Kinsella, Ray" <m...@ashroe.eu> wrote:
> On 13/07/2020 23:19, Stephen Hemminger wrote: > > On Mon, 13 Jul 2020 12:11:19 +0100 > > Vladimir Medvedkin <vladimir.medved...@intel.com> wrote: > > > >> This patch series implements vectorized lookup using AVX512 for > >> ipv4 dir24_8 and ipv6 trie algorithms. > >> Also introduced rte_fib_set_lookup_fn() to change lookup function type. > >> Added option to select lookup function type in testfib application. > >> > >> v6: > >> - style fixes > >> > >> v5: > >> - prefix zmm macro in rte_vect.h with RTE_X86 > >> - remove unnecessary typedef for _x86_zmm_t > >> - reword commit title > >> - fix typos > >> > >> v4: > >> - use __rte_aligned() instead of using compiler attribute directly > >> - rework and add comments to meson.build > >> > >> v3: > >> - separate out the AVX-512 code into a separate file > >> > >> v2: > >> - rename rte_zmm to __rte_x86_zmm to reflect its internal usage > >> - make runtime decision to use avx512 lookup > >> > >> Vladimir Medvedkin (8): > >> eal/x86: introduce AVX 512-bit type > >> fib: make lookup function type configurable > >> fib: move lookup definition into the header file > >> fib: introduce AVX512 lookup > >> fib6: make lookup function type configurable > >> fib6: move lookup definition into the header file > >> fib6: introduce AVX512 lookup > >> app/testfib: add support for different lookup functions > >> > >> app/test-fib/main.c | 58 +++++- > >> lib/librte_eal/x86/include/rte_vect.h | 19 ++ > >> lib/librte_fib/Makefile | 24 +++ > >> lib/librte_fib/dir24_8.c | 281 +++++--------------------- > >> lib/librte_fib/dir24_8.h | 226 ++++++++++++++++++++- > >> lib/librte_fib/dir24_8_avx512.c | 165 +++++++++++++++ > >> lib/librte_fib/dir24_8_avx512.h | 24 +++ > >> lib/librte_fib/meson.build | 31 +++ > >> lib/librte_fib/rte_fib.c | 21 +- > >> lib/librte_fib/rte_fib.h | 24 +++ > >> lib/librte_fib/rte_fib6.c | 20 +- > >> lib/librte_fib/rte_fib6.h | 22 ++ > >> lib/librte_fib/rte_fib_version.map | 2 + > >> lib/librte_fib/trie.c | 161 +++------------ > >> lib/librte_fib/trie.h | 119 ++++++++++- > >> lib/librte_fib/trie_avx512.c | 269 ++++++++++++++++++++++++ > >> lib/librte_fib/trie_avx512.h | 20 ++ > >> 17 files changed, 1114 insertions(+), 372 deletions(-) > >> create mode 100644 lib/librte_fib/dir24_8_avx512.c > >> create mode 100644 lib/librte_fib/dir24_8_avx512.h > >> create mode 100644 lib/librte_fib/trie_avx512.c > >> create mode 100644 lib/librte_fib/trie_avx512.h > >> > > > > Did anyone else see the recent AVX512 discussion from Linus: > > "I hope AVX512 dies a painful death, and that Intel starts fixing real > > problems > > instead of trying to create magic instructions to then create benchmarks > > that they can look good on. > > Yup - I saw this one. > Sweeping statements like these are good to provoke debate, the truth is > generally more nuanced. > If you continue to read the post, Linus appears to be mostly questioning > microprocessor design decisions. > > That is an interesting discussion, however the reality is that the technology > does exists and may be beneficial for Packet Processing. > > I would suggest, we continue to apply the same logic governing adoption of > any technology by DPDK. > When the technology is present and a clear benefit is shown, we use it with > caution. > > In the case of Vladimir's patch, > the user has to explicitly switch on the AVX512 lookup with > RTE_FIB_DIR24_8_VECTOR_AVX512. > Using what is available makes sense in DPDK.
