diff mbox series

[4/4] examples/dma: add minimal copy size parameter

Message ID 20220411025634.33032-5-fengchengwen@huawei.com (mailing list archive)
State Superseded, archived
Delegated to: Thomas Monjalon
Headers
Series bugfix and enhance features for DMA example |

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Commit Message

fengchengwen April 11, 2022, 2:56 a.m. UTC 
  This patch adds minimal copy size parameter(-m/--min-copy-size), so
when do copy by CPU or DMA, the real copy size will be the maximum of
mbuf's data_len and this parameter.

This parameter was designed to compare the performance between CPU copy
and DMA copy. User could send small packets with a high rate to drive
the performance test.

Signed-off-by: Chengwen Feng <fengchengwen@huawei.com>
---
 examples/dma/dmafwd.c | 27 ++++++++++++++++++++++++---
 1 file changed, 24 insertions(+), 3 deletions(-)

Comments

Bruce Richardson April 11, 2022, 9:27 a.m. UTC | #1 
On Mon, Apr 11, 2022 at 10:56:34AM +0800, Chengwen Feng wrote:
> This patch adds minimal copy size parameter(-m/--min-copy-size), so
> when do copy by CPU or DMA, the real copy size will be the maximum of
> mbuf's data_len and this parameter.
> 
> This parameter was designed to compare the performance between CPU copy
> and DMA copy. User could send small packets with a high rate to drive
> the performance test.
> 
> Signed-off-by: Chengwen Feng <fengchengwen@huawei.com>

Hi,

few comments inline below.

/Bruce

> ---
>  examples/dma/dmafwd.c | 27 ++++++++++++++++++++++++---
>  1 file changed, 24 insertions(+), 3 deletions(-)
> 
> diff --git a/examples/dma/dmafwd.c b/examples/dma/dmafwd.c
> index 6b1b777cb8..83094ba378 100644
> --- a/examples/dma/dmafwd.c
> +++ b/examples/dma/dmafwd.c
> @@ -25,6 +25,7 @@
>  #define CMD_LINE_OPT_RING_SIZE "ring-size"
>  #define CMD_LINE_OPT_BATCH_SIZE "dma-batch-size"
>  #define CMD_LINE_OPT_FRAME_SIZE "max-frame-size"
> +#define CMD_LINE_OPT_COPY_SIZE	"min-copy-size"

While I'm not sure this strictly belongs in an example app to show use of
dmadev, I can see the value of it. However, I suggest we need to make it
clearer that it's not directly relevant to the normal use of the app. I
suggest making the parameter "force-min-copy-size" to make it clearer that
it's an explicit override.

>  #define CMD_LINE_OPT_STATS_INTERVAL "stats-interval"
>  
>  /* configurable number of RX/TX ring descriptors */
> @@ -119,6 +120,7 @@ static volatile bool force_quit;
>  
>  static uint32_t dma_batch_sz = MAX_PKT_BURST;
>  static uint32_t max_frame_size;
> +static uint32_t min_copy_size;
>  
>  /* ethernet addresses of ports */
>  static struct rte_ether_addr dma_ports_eth_addr[RTE_MAX_ETHPORTS];
> @@ -208,7 +210,12 @@ print_stats(char *prgname)
>  		"Rx Queues = %d, ", nb_queues);
>  	status_strlen += snprintf(status_string + status_strlen,
>  		sizeof(status_string) - status_strlen,
> -		"Ring Size = %d", ring_size);
> +		"Ring Size = %d\n", ring_size);
> +	status_strlen += snprintf(status_string + status_strlen,
> +		sizeof(status_string) - status_strlen,
> +		"Min Copy Size = %u Packet Data Room Size = %u",
> +		min_copy_size, rte_pktmbuf_data_room_size(dma_pktmbuf_pool) -
> +		RTE_PKTMBUF_HEADROOM);
>  
>  	memset(&ts, 0, sizeof(struct total_statistics));
>  
> @@ -307,7 +314,8 @@ static inline void
>  pktmbuf_sw_copy(struct rte_mbuf *src, struct rte_mbuf *dst)
>  {
>  	rte_memcpy(rte_pktmbuf_mtod(dst, char *),
> -		rte_pktmbuf_mtod(src, char *), src->data_len);
> +		rte_pktmbuf_mtod(src, char *),
> +		RTE_MAX(src->data_len, min_copy_size));
>  }
>  /* >8 End of perform packet copy there is a user-defined function. */
>  
> @@ -324,7 +332,8 @@ dma_enqueue_packets(struct rte_mbuf *pkts[], struct rte_mbuf *pkts_copy[],
>  		ret = rte_dma_copy(dev_id, 0,
>  			rte_pktmbuf_iova(pkts[i]),
>  			rte_pktmbuf_iova(pkts_copy[i]),
> -			rte_pktmbuf_data_len(pkts[i]), 0);
> +			RTE_MAX(rte_pktmbuf_data_len(pkts[i]), min_copy_size),
> +			0);
>  
>  		if (ret < 0)
>  			break;
> @@ -576,6 +585,7 @@ dma_usage(const char *prgname)
>  	printf("%s [EAL options] -- -p PORTMASK [-q NQ]\n"
>  		"  -b --dma-batch-size: number of requests per DMA batch\n"
>  		"  -f --max-frame-size: max frame size\n"
> +		"  -m --min-copy-size: minimum copy length\n"

The help text needs to be expanded, again to make clear that this is for
perf comparison and the like. Something like "Force a minimum copy length,
	even for smaller packets"
fengchengwen April 11, 2022, 12:23 p.m. UTC | #2 
Hi Bruce, already fix in v2, Thanks.

On 2022/4/11 17:27, Bruce Richardson wrote:
> On Mon, Apr 11, 2022 at 10:56:34AM +0800, Chengwen Feng wrote:
>> This patch adds minimal copy size parameter(-m/--min-copy-size), so
>> when do copy by CPU or DMA, the real copy size will be the maximum of
>> mbuf's data_len and this parameter.
>>
>> This parameter was designed to compare the performance between CPU copy
>> and DMA copy. User could send small packets with a high rate to drive
>> the performance test.
>>
>> Signed-off-by: Chengwen Feng <fengchengwen@huawei.com>
> 
> Hi,
> 
> few comments inline below.
> 
> /Bruce
> 
>> ---
>>  examples/dma/dmafwd.c | 27 ++++++++++++++++++++++++---
>>  1 file changed, 24 insertions(+), 3 deletions(-)
>>
>> diff --git a/examples/dma/dmafwd.c b/examples/dma/dmafwd.c
>> index 6b1b777cb8..83094ba378 100644
>> --- a/examples/dma/dmafwd.c
>> +++ b/examples/dma/dmafwd.c
>> @@ -25,6 +25,7 @@
>>  #define CMD_LINE_OPT_RING_SIZE "ring-size"
>>  #define CMD_LINE_OPT_BATCH_SIZE "dma-batch-size"
>>  #define CMD_LINE_OPT_FRAME_SIZE "max-frame-size"
>> +#define CMD_LINE_OPT_COPY_SIZE	"min-copy-size"
> 
> While I'm not sure this strictly belongs in an example app to show use of
> dmadev, I can see the value of it. However, I suggest we need to make it
> clearer that it's not directly relevant to the normal use of the app. I
> suggest making the parameter "force-min-copy-size" to make it clearer that
> it's an explicit override.
> 
>>  #define CMD_LINE_OPT_STATS_INTERVAL "stats-interval"
>>  
>>  /* configurable number of RX/TX ring descriptors */
>> @@ -119,6 +120,7 @@ static volatile bool force_quit;
>>  
>>  static uint32_t dma_batch_sz = MAX_PKT_BURST;
>>  static uint32_t max_frame_size;

...

>> @@ -576,6 +585,7 @@ dma_usage(const char *prgname)
>>  	printf("%s [EAL options] -- -p PORTMASK [-q NQ]\n"
>>  		"  -b --dma-batch-size: number of requests per DMA batch\n"
>>  		"  -f --max-frame-size: max frame size\n"
>> +		"  -m --min-copy-size: minimum copy length\n"
> 
> The help text needs to be expanded, again to make clear that this is for
> perf comparison and the like. Something like "Force a minimum copy length,
> 	even for smaller packets"
> 
> 
> .
>
diff mbox series

Patch

diff --git a/examples/dma/dmafwd.c b/examples/dma/dmafwd.c
index 6b1b777cb8..83094ba378 100644
--- a/examples/dma/dmafwd.c
+++ b/examples/dma/dmafwd.c
@@ -25,6 +25,7 @@ 
 #define CMD_LINE_OPT_RING_SIZE "ring-size"
 #define CMD_LINE_OPT_BATCH_SIZE "dma-batch-size"
 #define CMD_LINE_OPT_FRAME_SIZE "max-frame-size"
+#define CMD_LINE_OPT_COPY_SIZE	"min-copy-size"
 #define CMD_LINE_OPT_STATS_INTERVAL "stats-interval"
 
 /* configurable number of RX/TX ring descriptors */
@@ -119,6 +120,7 @@  static volatile bool force_quit;
 
 static uint32_t dma_batch_sz = MAX_PKT_BURST;
 static uint32_t max_frame_size;
+static uint32_t min_copy_size;
 
 /* ethernet addresses of ports */
 static struct rte_ether_addr dma_ports_eth_addr[RTE_MAX_ETHPORTS];
@@ -208,7 +210,12 @@  print_stats(char *prgname)
 		"Rx Queues = %d, ", nb_queues);
 	status_strlen += snprintf(status_string + status_strlen,
 		sizeof(status_string) - status_strlen,
-		"Ring Size = %d", ring_size);
+		"Ring Size = %d\n", ring_size);
+	status_strlen += snprintf(status_string + status_strlen,
+		sizeof(status_string) - status_strlen,
+		"Min Copy Size = %u Packet Data Room Size = %u",
+		min_copy_size, rte_pktmbuf_data_room_size(dma_pktmbuf_pool) -
+		RTE_PKTMBUF_HEADROOM);
 
 	memset(&ts, 0, sizeof(struct total_statistics));
 
@@ -307,7 +314,8 @@  static inline void
 pktmbuf_sw_copy(struct rte_mbuf *src, struct rte_mbuf *dst)
 {
 	rte_memcpy(rte_pktmbuf_mtod(dst, char *),
-		rte_pktmbuf_mtod(src, char *), src->data_len);
+		rte_pktmbuf_mtod(src, char *),
+		RTE_MAX(src->data_len, min_copy_size));
 }
 /* >8 End of perform packet copy there is a user-defined function. */
 
@@ -324,7 +332,8 @@  dma_enqueue_packets(struct rte_mbuf *pkts[], struct rte_mbuf *pkts_copy[],
 		ret = rte_dma_copy(dev_id, 0,
 			rte_pktmbuf_iova(pkts[i]),
 			rte_pktmbuf_iova(pkts_copy[i]),
-			rte_pktmbuf_data_len(pkts[i]), 0);
+			RTE_MAX(rte_pktmbuf_data_len(pkts[i]), min_copy_size),
+			0);
 
 		if (ret < 0)
 			break;
@@ -576,6 +585,7 @@  dma_usage(const char *prgname)
 	printf("%s [EAL options] -- -p PORTMASK [-q NQ]\n"
 		"  -b --dma-batch-size: number of requests per DMA batch\n"
 		"  -f --max-frame-size: max frame size\n"
+		"  -m --min-copy-size: minimum copy length\n"
 		"  -p --portmask: hexadecimal bitmask of ports to configure\n"
 		"  -q NQ: number of RX queues per port (default is 1)\n"
 		"  --[no-]mac-updating: Enable or disable MAC addresses updating (enabled by default)\n"
@@ -621,6 +631,7 @@  dma_parse_args(int argc, char **argv, unsigned int nb_ports)
 		"b:"  /* dma batch size */
 		"c:"  /* copy type (sw|hw) */
 		"f:"  /* max frame size */
+		"m:"  /* min copy size */
 		"p:"  /* portmask */
 		"q:"  /* number of RX queues per port */
 		"s:"  /* ring size */
@@ -636,6 +647,7 @@  dma_parse_args(int argc, char **argv, unsigned int nb_ports)
 		{CMD_LINE_OPT_RING_SIZE, required_argument, NULL, 's'},
 		{CMD_LINE_OPT_BATCH_SIZE, required_argument, NULL, 'b'},
 		{CMD_LINE_OPT_FRAME_SIZE, required_argument, NULL, 'f'},
+		{CMD_LINE_OPT_COPY_SIZE, required_argument, NULL, 'm'},
 		{CMD_LINE_OPT_STATS_INTERVAL, required_argument, NULL, 'i'},
 		{NULL, 0, 0, 0}
 	};
@@ -670,6 +682,10 @@  dma_parse_args(int argc, char **argv, unsigned int nb_ports)
 			}
 			break;
 
+		case 'm':
+			min_copy_size = atoi(optarg);
+			break;
+
 		/* portmask */
 		case 'p':
 			dma_enabled_port_mask = dma_parse_portmask(optarg);
@@ -1068,6 +1084,11 @@  main(int argc, char **argv)
 		rte_exit(EXIT_FAILURE, "Cannot init mbuf pool\n");
 	/* >8 End of allocates mempool to hold the mbufs. */
 
+	if (min_copy_size >
+		(uint32_t)(rte_pktmbuf_data_room_size(dma_pktmbuf_pool) -
+			   RTE_PKTMBUF_HEADROOM))
+		rte_exit(EXIT_FAILURE, "Min copy size > packet mbuf size\n");
+
 	/* Initialize each port. 8< */
 	cfg.nb_ports = 0;
 	RTE_ETH_FOREACH_DEV(portid)