> Hi Zhihong Wang > > I test avx512 rte_memcpy found the performanc for ovs dpdk is lower than > avx2 rte_memcpy.
Hi Haifeng, AVX512 memcpy is marked as experimental and disabled by default, its benefit varies from case to case. So enable it only when the case (SW + HW setup with expected data pattern) is verified. BTW, it's not recommended to use micro benchmarks like test_memcpy_perf for memcpy performance report as they aren't likely able to reflect performance of real world applications, please find more details at https://software.intel.com/en-us/articles/performance-optimization-of-memcpy-in-dpdk Thanks Zhihong > > The vm loop test for ovs dpdk results: > avx512 is *15*Gbps > perf data: > 0.52 │ vmovdq (%r8,%r10,1),%zmm0 > 95.33 │ sub $0x40,%r9 > 0.45 │ add $0x40,%r8 > 0.60 │ vmovdq %zmm0,-0x40(%r8) > 1.84 │ cmp $0x3f,%r9 > │ ↓ ja f20 > │ lea -0x40(%rsi),%r8 > 0.15 │ or $0xffffffffffffffc0,%rsi > 0.21 │ and $0xffffffffffffffc0,%r8 > 0.00 │ lea 0x40(%rsi,%r8,1),%rsi > 0.00 │ vmovdq (%rcx,%rsi,1),%zmm0 > 0.22 │ vmovdq %zmm0,(%rdx,%rsi,1) > 0.67 │ ↓ jmpq c78 > │ mov -0x128(%rbp),%rdi > │ rex.R > │ .byte 0x89 > │ popfq > > avx2 is *18.8*Gbps > perf data: > 0.96 │ add %r9,%r13 > 66.04 │ vmovdq (%rdx),%ymm0 > 1.20 │ sub $0x40,%rdi > 1.53 │ add $0x40,%rdx > 10.83 │ vmovdq %ymm0,-0x40(%rdx,%r15,1) > 8.64 │ vmovdq -0x20(%rdx),%ymm0 > 7.58 │ vmovdq %ymm0,-0x40(%rdx,%r13,1) > > > dpdk version: v17.05 > ovs version: 2.8.90 > qemu version: QEMU emulator version 2.9.94 (v2.10.0-rc4-dirty) > > gcc version: gcc (GCC) 4.9.2 20150212 (Red Hat 4.9.2-6) > kernal version: 3.10.0 > > > compile dpdk: > CONFIG_RTE_ENABLE_AVX512=y > export DPDK_DIR=$PWD > export DPDK_TARGET=x86_64-native-linuxapp-gcc > export DPDK_BUILD=$DPDK_DIR/$DPDK_TARGET > make install T=$DPDK_TARGET DESTDIR=install > > compile ovs: > sh boot.sh > ./configure CFLAGS="-g -O2" --with-dpdk=$DPDK_BUILD --prefix=/usr -- > localstatedir=/var --sysconfdir=/etc > make -j > make install > > The test for dpdk test_memcpy_perf: > avx2： > ** rte_memcpy() - memcpy perf. tests (C = compile-time constant) ** > ======= ============== ============== ============== > ============== > Size Cache to cache Cache to mem Mem to cache Mem to mem > (bytes) (ticks) (ticks) (ticks) (ticks) > ------- -------------- -------------- -------------- -------------- > ========================== 32B aligned > ============================ > 64 6 - 10 27 - 52 30 - 39 56 - 97 > 512 24 - 44 251 - 271 145 - 217 396 - 447 > 1024 35 - 78 394 - 433 252 - 319 609 - 670 > ------- -------------- -------------- -------------- -------------- > C 64 3 - 9 28 - 31 29 - 40 55 - 66 > C 512 25 - 55 253 - 268 139 - 268 397 - 410 > C 1024 32 - 83 394 - 416 250 - 396 612 - 687 > =========================== Unaligned > ============================= > 64 8 - 9 85 - 71 45 - 45 125 - 121 > 512 33 - 49 282 - 305 153 - 252 420 - 478 > 1024 42 - 83 409 - 491 259 - 389 640 - 748 > ------- -------------- -------------- -------------- -------------- > C 64 4 - 9 42 - 46 39 - 46 76 - 90 > C 512 33 - 55 280 - 272 153 - 281 421 - 415 > C 1024 41 - 83 407 - 427 258 - 405 578 - 701 > ======= ============== ============== ============== > ============== > > avx512： > ** rte_memcpy() - memcpy perf. tests (C = compile-time constant) ** > ======= ============== ============== ============== > ============== > Size Cache to cache Cache to mem Mem to cache Mem to mem > (bytes) (ticks) (ticks) (ticks) (ticks) > ------- -------------- -------------- -------------- -------------- > ========================== 64B aligned > ============================ > 64 6 - 9 18 - 33 24 - 38 40 - 65 > 512 18 - 44 178 - 262 138 - 218 309 - 429 > 1024 27 - 79 338 - 430 250 - 322 560 - 674 > ------- -------------- -------------- -------------- -------------- > C 64 3 - 9 18 - 20 23 - 41 39 - 50 > C 512 15 - 54 205 - 270 134 - 268 304 - 409 > C 1024 24 - 83 371 - 414 242 - 400 550 - 692 > =========================== Unaligned > ============================= > 64 8 - 9 87 - 74 45 - 48 125 - 118 > 512 23 - 49 298 - 311 150 - 250 437 - 482 > 1024 36 - 83 427 - 505 259 - 406 633 - 754 > ------- -------------- -------------- -------------- -------------- > C 64 4 - 9 42 - 46 39 - 46 76 - 94 > C 512 23 - 55 246 - 277 152 - 290 349 - 426 > C 1024 38 - 83 398 - 431 258 - 416 634 - 725 > ======= ============== ============== ============== > ============== > > > > > > >
