Re: [PATCH v2 1/2] examples/l3fwd: common packet group functionality

[Konstantin Ananyev <konstantin.v.ananyev@yandex.ru>]

17/06/2022 08:50, Rahul Bhansali пишет:
> CC: Konstantin Ananyev
> 
>> -----Original Message-----
>> From: Rahul Bhansali <rbhansali@marvell.com>
>> Sent: Friday, June 17, 2022 1:13 PM
>> To: dev@dpdk.org; Ruifeng Wang <ruifeng.wang@arm.com>
>> Cc: Jerin Jacob Kollanukkaran <jerinj@marvell.com>; Rahul Bhansali
>> <rbhansali@marvell.com>
>> Subject: [PATCH v2 1/2] examples/l3fwd: common packet group functionality
>>
>> This will make the packet grouping function common, so that other examples
>> can utilize as per need.
>>
>> Signed-off-by: Rahul Bhansali <rbhansali@marvell.com>
>> ---
>> Changes in v2: New patch to address review comment.
>>
>>   examples/common/neon_common.h |  50 ++++++++++++
>>   examples/common/pkt_group.h   | 139
>> ++++++++++++++++++++++++++++++++++
>>   examples/l3fwd/Makefile       |   5 +-
>>   examples/l3fwd/l3fwd.h        |   2 -
>>   examples/l3fwd/l3fwd_common.h | 129 +------------------------------
>>   examples/l3fwd/l3fwd_neon.h   |  43 +----------
>>   examples/meson.build          |   2 +-
>>   7 files changed, 198 insertions(+), 172 deletions(-)  create mode 100644
>> examples/common/neon_common.h  create mode 100644
>> examples/common/pkt_group.h
>>
>> diff --git a/examples/common/neon_common.h
>> b/examples/common/neon_common.h new file mode 100644 index
>> 0000000000..f01b5ab6bc
>> --- /dev/null
>> +++ b/examples/common/neon_common.h
>> @@ -0,0 +1,50 @@
>> +/* SPDX-License-Identifier: BSD-3-Clause
>> + * Copyright(c) 2016-2018 Intel Corporation.
>> + * Copyright(c) 2017-2018 Linaro Limited.
>> + * Copyright(C) 2022 Marvell.
>> + */
>> +
>> +#ifndef _NEON_COMMON_H_
>> +#define _NEON_COMMON_H_
>> +
>> +#include "pkt_group.h"
>> +
>> +/*
>> + * Group consecutive packets with the same destination port in bursts of 4.
>> + * Suppose we have array of destination ports:
>> + * dst_port[] = {a, b, c, d,, e, ... }
>> + * dp1 should contain: <a, b, c, d>, dp2: <b, c, d, e>.
>> + * We doing 4 comparisons at once and the result is 4 bit mask.
>> + * This mask is used as an index into prebuild array of pnum values.
>> + */
>> +static inline uint16_t *
>> +neon_port_groupx4(uint16_t pn[FWDSTEP + 1], uint16_t *lp, uint16x8_t dp1,
>> +		  uint16x8_t dp2)
>> +{
>> +	union {
>> +		uint16_t u16[FWDSTEP + 1];
>> +		uint64_t u64;
>> +	} *pnum = (void *)pn;
>> +
>> +	uint16x8_t mask = {1, 2, 4, 8, 0, 0, 0, 0};
>> +	int32_t v;
>> +
>> +	dp1 = vceqq_u16(dp1, dp2);
>> +	dp1 = vandq_u16(dp1, mask);
>> +	v = vaddvq_u16(dp1);
>> +
>> +	/* update last port counter. */hh
>> +	lp[0] += gptbl[v].lpv;
>> +	rte_compiler_barrier();
>> +
>> +	/* if dest port value has changed. */
>> +	if (v != GRPMSK) {
>> +		pnum->u64 = gptbl[v].pnum;
>> +		pnum->u16[FWDSTEP] = 1;
>> +		lp = pnum->u16 + gptbl[v].idx;
>> +	}
>> +
>> +	return lp;
>> +}

Thanks for the effort.
As I can see this function: port_groupx4() is nearly identical for all 3 
platforms: sse/nenon/altivec (except of course built-in arch-specific 
instincts).
In fact, even comemnts are identical.
I wonder can we have something like:
examples/common/<arch>/port_group.h
and for each arch will have defined port_groupx4(...)
?

>> +
>> +#endif /* _NEON_COMMON_H_ */
>> diff --git a/examples/common/pkt_group.h b/examples/common/pkt_group.h
>> new file mode 100644 index 0000000000..8b26d9380f
>> --- /dev/null
>> +++ b/examples/common/pkt_group.h
>> @@ -0,0 +1,139 @@
>> +/* SPDX-License-Identifier: BSD-3-Clause
>> + * Copyright(c) 2016-2018 Intel Corporation.
>> + * Copyright(c) 2017-2018 Linaro Limited.
>> + * Copyright(C) 2022 Marvell.
>> + */
>> +
>> +#ifndef _PKT_GROUP_H_
>> +#define _PKT_GROUP_H_
>> +
>> +#define FWDSTEP	4
>> +
>> +/*
>> + * Group consecutive packets with the same destination port into one burst.
>> + * To avoid extra latency this is done together with some other packet
>> + * processing, but after we made a final decision about packet's destination.
>> + * To do this we maintain:
>> + * pnum - array of number of consecutive packets with the same dest
>> +port for
>> + * each packet in the input burst.
>> + * lp - pointer to the last updated element in the pnum.
>> + * dlp - dest port value lp corresponds to.
>> + */
>> +
>> +#define	GRPSZ	(1 << FWDSTEP)
>> +#define	GRPMSK	(GRPSZ - 1)
>> +
>> +#define GROUP_PORT_STEP(dlp, dcp, lp, pn, idx)	do { \
>> +	if (likely((dlp) == (dcp)[(idx)])) {         \
>> +		(lp)[0]++;                           \
>> +	} else {                                     \
>> +		(dlp) = (dcp)[idx];                  \
>> +		(lp) = (pn) + (idx);                 \
>> +		(lp)[0] = 1;                         \
>> +	}                                            \
>> +} while (0)
>> +
>> +static const struct {
>> +	uint64_t pnum; /* prebuild 4 values for pnum[]. */
>> +	int32_t  idx;  /* index for new last updated elemnet. */
>> +	uint16_t lpv;  /* add value to the last updated element. */ }
>> +gptbl[GRPSZ] = {
>> +	{
>> +		/* 0: a != b, b != c, c != d, d != e */
>> +		.pnum = UINT64_C(0x0001000100010001),
>> +		.idx = 4,
>> +		.lpv = 0,
>> +	},
>> +	{
>> +		/* 1: a == b, b != c, c != d, d != e */
>> +		.pnum = UINT64_C(0x0001000100010002),
>> +		.idx = 4,
>> +		.lpv = 1,
>> +	},
>> +	{
>> +		/* 2: a != b, b == c, c != d, d != e */
>> +		.pnum = UINT64_C(0x0001000100020001),
>> +		.idx = 4,
>> +		.lpv = 0,
>> +	},
>> +	{
>> +		/* 3: a == b, b == c, c != d, d != e */
>> +		.pnum = UINT64_C(0x0001000100020003),
>> +		.idx = 4,
>> +		.lpv = 2,
>> +	},
>> +	{
>> +		/* 4: a != b, b != c, c == d, d != e */
>> +		.pnum = UINT64_C(0x0001000200010001),
>> +		.idx = 4,
>> +		.lpv = 0,
>> +	},
>> +	{
>> +		/* 5: a == b, b != c, c == d, d != e */
>> +		.pnum = UINT64_C(0x0001000200010002),
>> +		.idx = 4,
>> +		.lpv = 1,
>> +	},
>> +	{
>> +		/* 6: a != b, b == c, c == d, d != e */
>> +		.pnum = UINT64_C(0x0001000200030001),
>> +		.idx = 4,
>> +		.lpv = 0,
>> +	},
>> +	{
>> +		/* 7: a == b, b == c, c == d, d != e */
>> +		.pnum = UINT64_C(0x0001000200030004),
>> +		.idx = 4,
>> +		.lpv = 3,
>> +	},
>> +	{
>> +		/* 8: a != b, b != c, c != d, d == e */
>> +		.pnum = UINT64_C(0x0002000100010001),
>> +		.idx = 3,
>> +		.lpv = 0,
>> +	},
>> +	{
>> +		/* 9: a == b, b != c, c != d, d == e */
>> +		.pnum = UINT64_C(0x0002000100010002),
>> +		.idx = 3,
>> +		.lpv = 1,
>> +	},
>> +	{
>> +		/* 0xa: a != b, b == c, c != d, d == e */
>> +		.pnum = UINT64_C(0x0002000100020001),
>> +		.idx = 3,
>> +		.lpv = 0,
>> +	},
>> +	{
>> +		/* 0xb: a == b, b == c, c != d, d == e */
>> +		.pnum = UINT64_C(0x0002000100020003),
>> +		.idx = 3,
>> +		.lpv = 2,
>> +	},
>> +	{
>> +		/* 0xc: a != b, b != c, c == d, d == e */
>> +		.pnum = UINT64_C(0x0002000300010001),
>> +		.idx = 2,
>> +		.lpv = 0,
>> +	},
>> +	{
>> +		/* 0xd: a == b, b != c, c == d, d == e */
>> +		.pnum = UINT64_C(0x0002000300010002),
>> +		.idx = 2,
>> +		.lpv = 1,
>> +	},
>> +	{
>> +		/* 0xe: a != b, b == c, c == d, d == e */
>> +		.pnum = UINT64_C(0x0002000300040001),
>> +		.idx = 1,
>> +		.lpv = 0,
>> +	},
>> +	{
>> +		/* 0xf: a == b, b == c, c == d, d == e */
>> +		.pnum = UINT64_C(0x0002000300040005),
>> +		.idx = 0,
>> +		.lpv = 4,
>> +	},
>> +};
>> +
>> +#endif /* _PKT_GROUP_H_ */
>> diff --git a/examples/l3fwd/Makefile b/examples/l3fwd/Makefile index
>> 8efe6378e2..8dbe85c2e6 100644
>> --- a/examples/l3fwd/Makefile
>> +++ b/examples/l3fwd/Makefile
>> @@ -22,6 +22,7 @@ shared: build/$(APP)-shared
>>   static: build/$(APP)-static
>>   	ln -sf $(APP)-static build/$(APP)
>>
>> +INCLUDES =-I../common
>>   PC_FILE := $(shell $(PKGCONF) --path libdpdk 2>/dev/null)  CFLAGS += -O3
>> $(shell $(PKGCONF) --cflags libdpdk)  # Added for 'rte_eth_link_to_str()'
>> @@ -38,10 +39,10 @@ endif
>>   endif
>>
>>   build/$(APP)-shared: $(SRCS-y) Makefile $(PC_FILE) | build
>> -	$(CC) $(CFLAGS) $(SRCS-y) -o $@ $(LDFLAGS) $(LDFLAGS_SHARED)
>> +	$(CC) $(CFLAGS) $(SRCS-y) $(INCLUDES) -o $@ $(LDFLAGS)
>> +$(LDFLAGS_SHARED)
>>
>>   build/$(APP)-static: $(SRCS-y) Makefile $(PC_FILE) | build
>> -	$(CC) $(CFLAGS) $(SRCS-y) -o $@ $(LDFLAGS) $(LDFLAGS_STATIC)
>> +	$(CC) $(CFLAGS) $(SRCS-y) $(INCLUDES) -o $@ $(LDFLAGS)
>> +$(LDFLAGS_STATIC)
>>
>>   build:
>>   	@mkdir -p $@
>> diff --git a/examples/l3fwd/l3fwd.h b/examples/l3fwd/l3fwd.h index
>> 8a52c90755..40b5f32a9e 100644
>> --- a/examples/l3fwd/l3fwd.h
>> +++ b/examples/l3fwd/l3fwd.h
>> @@ -44,8 +44,6 @@
>>   /* Used to mark destination port as 'invalid'. */
>>   #define	BAD_PORT ((uint16_t)-1)
>>
>> -#define FWDSTEP	4
>> -
>>   /* replace first 12B of the ethernet header. */
>>   #define	MASK_ETH 0x3f
>>
>> diff --git a/examples/l3fwd/l3fwd_common.h
>> b/examples/l3fwd/l3fwd_common.h index 8e4c27218f..224b1c08e8 100644
>> --- a/examples/l3fwd/l3fwd_common.h
>> +++ b/examples/l3fwd/l3fwd_common.h
>> @@ -7,6 +7,8 @@
>>   #ifndef _L3FWD_COMMON_H_
>>   #define _L3FWD_COMMON_H_
>>
>> +#include "pkt_group.h"
>> +
>>   #ifdef DO_RFC_1812_CHECKS
>>
>>   #define	IPV4_MIN_VER_IHL	0x45
>> @@ -50,133 +52,6 @@ rfc1812_process(struct rte_ipv4_hdr *ipv4_hdr, uint16_t
>> *dp, uint32_t ptype)
>>   #define	rfc1812_process(mb, dp, ptype)	do { } while (0)
>>   #endif /* DO_RFC_1812_CHECKS */
>>
>> -/*
>> - * We group consecutive packets with the same destination port into one burst.
>> - * To avoid extra latency this is done together with some other packet
>> - * processing, but after we made a final decision about packet's destination.
>> - * To do this we maintain:
>> - * pnum - array of number of consecutive packets with the same dest port for
>> - * each packet in the input burst.
>> - * lp - pointer to the last updated element in the pnum.
>> - * dlp - dest port value lp corresponds to.
>> - */
>> -
>> -#define	GRPSZ	(1 << FWDSTEP)
>> -#define	GRPMSK	(GRPSZ - 1)
>> -
>> -#define GROUP_PORT_STEP(dlp, dcp, lp, pn, idx)	do { \
>> -	if (likely((dlp) == (dcp)[(idx)])) {             \
>> -		(lp)[0]++;                                   \
>> -	} else {                                         \
>> -		(dlp) = (dcp)[idx];                          \
>> -		(lp) = (pn) + (idx);                         \
>> -		(lp)[0] = 1;                                 \
>> -	}                                                \
>> -} while (0)
>> -
>> -static const struct {
>> -	uint64_t pnum; /* prebuild 4 values for pnum[]. */
>> -	int32_t  idx;  /* index for new last updated element. */
>> -	uint16_t lpv;  /* add value to the last updated element. */
>> -} gptbl[GRPSZ] = {
>> -	{
>> -		/* 0: a != b, b != c, c != d, d != e */
>> -		.pnum = UINT64_C(0x0001000100010001),
>> -		.idx = 4,
>> -		.lpv = 0,
>> -	},
>> -	{
>> -		/* 1: a == b, b != c, c != d, d != e */
>> -		.pnum = UINT64_C(0x0001000100010002),
>> -		.idx = 4,
>> -		.lpv = 1,
>> -	},
>> -	{
>> -		/* 2: a != b, b == c, c != d, d != e */
>> -		.pnum = UINT64_C(0x0001000100020001),
>> -		.idx = 4,
>> -		.lpv = 0,
>> -	},
>> -	{
>> -		/* 3: a == b, b == c, c != d, d != e */
>> -		.pnum = UINT64_C(0x0001000100020003),
>> -		.idx = 4,
>> -		.lpv = 2,
>> -	},
>> -	{
>> -		/* 4: a != b, b != c, c == d, d != e */
>> -		.pnum = UINT64_C(0x0001000200010001),
>> -		.idx = 4,
>> -		.lpv = 0,
>> -	},
>> -	{
>> -		/* 5: a == b, b != c, c == d, d != e */
>> -		.pnum = UINT64_C(0x0001000200010002),
>> -		.idx = 4,
>> -		.lpv = 1,
>> -	},
>> -	{
>> -		/* 6: a != b, b == c, c == d, d != e */
>> -		.pnum = UINT64_C(0x0001000200030001),
>> -		.idx = 4,
>> -		.lpv = 0,
>> -	},
>> -	{
>> -		/* 7: a == b, b == c, c == d, d != e */
>> -		.pnum = UINT64_C(0x0001000200030004),
>> -		.idx = 4,
>> -		.lpv = 3,
>> -	},
>> -	{
>> -		/* 8: a != b, b != c, c != d, d == e */
>> -		.pnum = UINT64_C(0x0002000100010001),
>> -		.idx = 3,
>> -		.lpv = 0,
>> -	},
>> -	{
>> -		/* 9: a == b, b != c, c != d, d == e */
>> -		.pnum = UINT64_C(0x0002000100010002),
>> -		.idx = 3,
>> -		.lpv = 1,
>> -	},
>> -	{
>> -		/* 0xa: a != b, b == c, c != d, d == e */
>> -		.pnum = UINT64_C(0x0002000100020001),
>> -		.idx = 3,
>> -		.lpv = 0,
>> -	},
>> -	{
>> -		/* 0xb: a == b, b == c, c != d, d == e */
>> -		.pnum = UINT64_C(0x0002000100020003),
>> -		.idx = 3,
>> -		.lpv = 2,
>> -	},
>> -	{
>> -		/* 0xc: a != b, b != c, c == d, d == e */
>> -		.pnum = UINT64_C(0x0002000300010001),
>> -		.idx = 2,
>> -		.lpv = 0,
>> -	},
>> -	{
>> -		/* 0xd: a == b, b != c, c == d, d == e */
>> -		.pnum = UINT64_C(0x0002000300010002),
>> -		.idx = 2,
>> -		.lpv = 1,
>> -	},
>> -	{
>> -		/* 0xe: a != b, b == c, c == d, d == e */
>> -		.pnum = UINT64_C(0x0002000300040001),
>> -		.idx = 1,
>> -		.lpv = 0,
>> -	},
>> -	{
>> -		/* 0xf: a == b, b == c, c == d, d == e */
>> -		.pnum = UINT64_C(0x0002000300040005),
>> -		.idx = 0,
>> -		.lpv = 4,
>> -	},
>> -};
>> -
>>   static __rte_always_inline void
>>   send_packetsx4(struct lcore_conf *qconf, uint16_t port, struct rte_mbuf *m[],
>>   		uint32_t num)
>> diff --git a/examples/l3fwd/l3fwd_neon.h b/examples/l3fwd/l3fwd_neon.h
>> index e3d33a5229..5fa765b640 100644
>> --- a/examples/l3fwd/l3fwd_neon.h
>> +++ b/examples/l3fwd/l3fwd_neon.h
>> @@ -7,6 +7,7 @@
>>   #define _L3FWD_NEON_H_
>>
>>   #include "l3fwd.h"
>> +#include "neon_common.h"
>>   #include "l3fwd_common.h"
>>
>>   /*
>> @@ -62,44 +63,6 @@ processx4_step3(struct rte_mbuf *pkt[FWDSTEP],
>> uint16_t dst_port[FWDSTEP])
>>   			&dst_port[3], pkt[3]->packet_type);
>>   }
>>
>> -/*
>> - * Group consecutive packets with the same destination port in bursts of 4.
>> - * Suppose we have array of destination ports:
>> - * dst_port[] = {a, b, c, d,, e, ... }
>> - * dp1 should contain: <a, b, c, d>, dp2: <b, c, d, e>.
>> - * We doing 4 comparisons at once and the result is 4 bit mask.
>> - * This mask is used as an index into prebuild array of pnum values.
>> - */
>> -static inline uint16_t *
>> -port_groupx4(uint16_t pn[FWDSTEP + 1], uint16_t *lp, uint16x8_t dp1,
>> -	     uint16x8_t dp2)
>> -{
>> -	union {
>> -		uint16_t u16[FWDSTEP + 1];
>> -		uint64_t u64;
>> -	} *pnum = (void *)pn;
>> -
>> -	int32_t v;
>> -	uint16x8_t mask = {1, 2, 4, 8, 0, 0, 0, 0};
>> -
>> -	dp1 = vceqq_u16(dp1, dp2);
>> -	dp1 = vandq_u16(dp1, mask);
>> -	v = vaddvq_u16(dp1);
>> -
>> -	/* update last port counter. */
>> -	lp[0] += gptbl[v].lpv;
>> -	rte_compiler_barrier();
>> -
>> -	/* if dest port value has changed. */
>> -	if (v != GRPMSK) {
>> -		pnum->u64 = gptbl[v].pnum;
>> -		pnum->u16[FWDSTEP] = 1;
>> -		lp = pnum->u16 + gptbl[v].idx;
>> -	}
>> -
>> -	return lp;
>> -}
>> -
>>   /**
>>    * Process one packet:
>>    * Update source and destination MAC addresses in the ethernet header.
>> @@ -161,7 +124,7 @@ send_packets_multi(struct lcore_conf *qconf, struct
>> rte_mbuf **pkts_burst,
>>   			 * <d[j-3], d[j-2], d[j-1], d[j], ... >
>>   			 */
>>   			dp2 = vld1q_u16(&dst_port[j - FWDSTEP + 1]);
>> -			lp  = port_groupx4(&pnum[j - FWDSTEP], lp, dp1, dp2);
>> +			lp  = neon_port_groupx4(&pnum[j - FWDSTEP], lp, dp1,
>> dp2);
>>
>>   			/*
>>   			 * dp1:
>> @@ -175,7 +138,7 @@ send_packets_multi(struct lcore_conf *qconf, struct
>> rte_mbuf **pkts_burst,
>>   		 */
>>   		dp2 = vextq_u16(dp1, dp1, 1);
>>   		dp2 = vsetq_lane_u16(vgetq_lane_u16(dp2, 2), dp2, 3);
>> -		lp  = port_groupx4(&pnum[j - FWDSTEP], lp, dp1, dp2);
>> +		lp  = neon_port_groupx4(&pnum[j - FWDSTEP], lp, dp1, dp2);
>>
>>   		/*
>>   		 * remove values added by the last repeated diff --git
>> a/examples/meson.build b/examples/meson.build index
>> 78de0e1f37..81e93799f2 100644
>> --- a/examples/meson.build
>> +++ b/examples/meson.build
>> @@ -97,7 +97,7 @@ foreach example: examples
>>       ldflags = default_ldflags
>>
>>       ext_deps = []
>> -    includes = [include_directories(example)]
>> +    includes = [include_directories(example, 'common')]
>>       deps = ['eal', 'mempool', 'net', 'mbuf', 'ethdev', 'cmdline']
>>       subdir(example)
>>
>> --
>> 2.25.1
>