[dpdk-dev] [PATCH v7 06/17] lib: add SIMD flow matching to distributor

David Hunt david.hunt at intel.com
Tue Feb 21 04:17:42 CET 2017


Add an optimised version of the in-flight flow matching algorithm
using SIMD instructions. This should give up to 1.5x over the scalar
versions performance.

Falls back to scalar version if SSE4.2 not available

Signed-off-by: David Hunt <david.hunt at intel.com>
---
 lib/librte_distributor/Makefile                    |   7 ++
 lib/librte_distributor/rte_distributor.c           |  16 ++-
 .../rte_distributor_match_generic.c                |  43 ++++++++
 lib/librte_distributor/rte_distributor_match_sse.c | 113 +++++++++++++++++++++
 lib/librte_distributor/rte_distributor_private.h   |   5 +
 5 files changed, 182 insertions(+), 2 deletions(-)
 create mode 100644 lib/librte_distributor/rte_distributor_match_generic.c
 create mode 100644 lib/librte_distributor/rte_distributor_match_sse.c

diff --git a/lib/librte_distributor/Makefile b/lib/librte_distributor/Makefile
index 276695a..5b599c6 100644
--- a/lib/librte_distributor/Makefile
+++ b/lib/librte_distributor/Makefile
@@ -44,6 +44,13 @@ LIBABIVER := 1
 # all source are stored in SRCS-y
 SRCS-$(CONFIG_RTE_LIBRTE_DISTRIBUTOR) := rte_distributor_v20.c
 SRCS-$(CONFIG_RTE_LIBRTE_DISTRIBUTOR) += rte_distributor.c
+ifeq ($(CONFIG_RTE_ARCH_X86),y)
+SRCS-$(CONFIG_RTE_LIBRTE_DISTRIBUTOR) += rte_distributor_match_sse.c
+CFLAGS_rte_distributor_match_sse.o += -msse4.2
+else
+SRCS-$(CONFIG_RTE_LIBRTE_DISTRIBUTOR) += rte_distributor_match_generic.c
+endif
+
 
 # install this header file
 SYMLINK-$(CONFIG_RTE_LIBRTE_DISTRIBUTOR)-include := rte_distributor_v20.h
diff --git a/lib/librte_distributor/rte_distributor.c b/lib/librte_distributor/rte_distributor.c
index ae8d508..b8e171c 100644
--- a/lib/librte_distributor/rte_distributor.c
+++ b/lib/librte_distributor/rte_distributor.c
@@ -392,7 +392,13 @@ rte_distributor_process(struct rte_distributor *d,
 		for (; i < RTE_DIST_BURST_SIZE; i++)
 			flows[i] = 0;
 
-		find_match_scalar(d, &flows[0], &matches[0]);
+		switch (d->dist_match_fn) {
+		case RTE_DIST_MATCH_VECTOR:
+			find_match_vec(d, &flows[0], &matches[0]);
+			break;
+		default:
+			find_match_scalar(d, &flows[0], &matches[0]);
+		}
 
 		/*
 		 * Matches array now contain the intended worker ID (+1) of
@@ -608,7 +614,13 @@ rte_distributor_create(const char *name,
 	snprintf(d->name, sizeof(d->name), "%s", name);
 	d->num_workers = num_workers;
 	d->alg_type = alg_type;
-	d->dist_match_fn = RTE_DIST_MATCH_SCALAR;
+
+#if defined(RTE_ARCH_X86)
+	if (rte_cpu_get_flag_enabled(RTE_CPUFLAG_SSE4_2)) {
+		d->dist_match_fn = RTE_DIST_MATCH_VECTOR;
+	} else
+#endif
+		d->dist_match_fn = RTE_DIST_MATCH_SCALAR;
 
 	/*
 	 * Set up the backog tags so they're pointing at the second cache
diff --git a/lib/librte_distributor/rte_distributor_match_generic.c b/lib/librte_distributor/rte_distributor_match_generic.c
new file mode 100644
index 0000000..4925a78
--- /dev/null
+++ b/lib/librte_distributor/rte_distributor_match_generic.c
@@ -0,0 +1,43 @@
+/*-
+ *   BSD LICENSE
+ *
+ *   Copyright(c) 2017 Intel Corporation. All rights reserved.
+ *
+ *   Redistribution and use in source and binary forms, with or without
+ *   modification, are permitted provided that the following conditions
+ *   are met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in
+ *       the documentation and/or other materials provided with the
+ *       distribution.
+ *     * Neither the name of Intel Corporation nor the names of its
+ *       contributors may be used to endorse or promote products derived
+ *       from this software without specific prior written permission.
+ *
+ *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <rte_mbuf.h>
+#include "rte_distributor_private.h"
+#include "rte_distributor.h"
+
+void
+find_match_vec(struct rte_distributor *d,
+			uint16_t *data_ptr,
+			uint16_t *output_ptr)
+{
+	find_match_scalar(d, data_ptr, output_ptr);
+}
diff --git a/lib/librte_distributor/rte_distributor_match_sse.c b/lib/librte_distributor/rte_distributor_match_sse.c
new file mode 100644
index 0000000..a84097f
--- /dev/null
+++ b/lib/librte_distributor/rte_distributor_match_sse.c
@@ -0,0 +1,113 @@
+/*-
+ *   BSD LICENSE
+ *
+ *   Copyright(c) 2017 Intel Corporation. All rights reserved.
+ *
+ *   Redistribution and use in source and binary forms, with or without
+ *   modification, are permitted provided that the following conditions
+ *   are met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in
+ *       the documentation and/or other materials provided with the
+ *       distribution.
+ *     * Neither the name of Intel Corporation nor the names of its
+ *       contributors may be used to endorse or promote products derived
+ *       from this software without specific prior written permission.
+ *
+ *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <rte_mbuf.h>
+#include "rte_distributor_private.h"
+#include "rte_distributor.h"
+#include "smmintrin.h"
+
+
+void
+find_match_vec(struct rte_distributor *d,
+			uint16_t *data_ptr,
+			uint16_t *output_ptr)
+{
+	/* Setup */
+	__m128i incoming_fids;
+	__m128i inflight_fids;
+	__m128i preflight_fids;
+	__m128i wkr;
+	__m128i mask1;
+	__m128i mask2;
+	__m128i output;
+	struct rte_distributor_backlog *bl;
+	uint16_t i;
+
+	/*
+	 * Function overview:
+	 * 2. Loop through all worker ID's
+	 *  2a. Load the current inflights for that worker into an xmm reg
+	 *  2b. Load the current backlog for that worker into an xmm reg
+	 *  2c. use cmpestrm to intersect flow_ids with backlog and inflights
+	 *  2d. Add any matches to the output
+	 * 3. Write the output xmm (matching worker ids).
+	 */
+
+
+	output = _mm_set1_epi16(0);
+	incoming_fids = _mm_load_si128((__m128i *)data_ptr);
+
+	for (i = 0; i < d->num_workers; i++) {
+		bl = &d->backlog[i];
+
+		inflight_fids =
+			_mm_load_si128((__m128i *)&(d->in_flight_tags[i]));
+		preflight_fids =
+			_mm_load_si128((__m128i *)(bl->tags));
+
+		/*
+		 * Any incoming_fid that exists anywhere in inflight_fids will
+		 * have 0xffff in same position of the mask as the incoming fid
+		 * Example (shortened to bytes for brevity):
+		 * incoming_fids   0x01 0x02 0x03 0x04 0x05 0x06 0x07 0x08
+		 * inflight_fids   0x03 0x05 0x07 0x00 0x00 0x00 0x00 0x00
+		 * mask            0x00 0x00 0xff 0x00 0xff 0x00 0xff 0x00
+		 */
+
+		mask1 = _mm_cmpestrm(inflight_fids, 8, incoming_fids, 8,
+			_SIDD_UWORD_OPS |
+			_SIDD_CMP_EQUAL_ANY |
+			_SIDD_UNIT_MASK);
+		mask2 = _mm_cmpestrm(preflight_fids, 8, incoming_fids, 8,
+			_SIDD_UWORD_OPS |
+			_SIDD_CMP_EQUAL_ANY |
+			_SIDD_UNIT_MASK);
+
+		mask1 = _mm_or_si128(mask1, mask2);
+		/*
+		 * Now mask contains 0xffff where there's a match.
+		 * Next we need to store the worker_id in the relevant position
+		 * in the output.
+		 */
+
+		wkr = _mm_set1_epi16(i+1);
+		mask1 = _mm_and_si128(mask1, wkr);
+		output = _mm_or_si128(mask1, output);
+	}
+
+	/*
+	 * At this stage, the output 128-bit contains 8 16-bit values, with
+	 * each non-zero value containing the worker ID on which the
+	 * corresponding flow is pinned to.
+	 */
+	_mm_store_si128((__m128i *)output_ptr, output);
+}
diff --git a/lib/librte_distributor/rte_distributor_private.h b/lib/librte_distributor/rte_distributor_private.h
index c8e0f98..c1d852b 100644
--- a/lib/librte_distributor/rte_distributor_private.h
+++ b/lib/librte_distributor/rte_distributor_private.h
@@ -190,6 +190,11 @@ find_match_scalar(struct rte_distributor *d,
 			uint16_t *data_ptr,
 			uint16_t *output_ptr);
 
+void
+find_match_vec(struct rte_distributor *d,
+			uint16_t *data_ptr,
+			uint16_t *output_ptr);
+
 #ifdef __cplusplus
 }
 #endif
-- 
2.7.4



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