Re: [dpdk-dev] [PATCH V2] app/testpmd: support Tx mbuf free on demand cmd

[oulijun <oulijun@huawei.com>]

在 2021/3/9 1:33, Ferruh Yigit 写道:
> On 3/5/2021 9:57 AM, Lijun Ou wrote:
>> From: Chengwen Feng <fengchengwen@huawei.com>
>>
>> This patch support tx_done_cleanup command:
>> tx_done_cleanup port (port_id) (queue_id) (free_cnt)
>>
>> Users must make sure there are no concurrent access to the same Tx
>> queue (like rte_eth_tx_burst, rte_eth_dev_tx_queue_stop and so on)
>> this command executed.
>>
> 
> Hi Lijun,
> 
> Is the intention to test the PMD implementation?
Yes
> As you highlighted the API is for the datapath, a command for it is not 
> easy to use, not sure how useful it will be.
> Perhaps it can be option to use this API in a forwarding engine, like 
> 'txonly', controlled by a command, but again not sure what to 
> observe/measure etc..
> 
We want to do this. But it is diffcult to control the number of sent 
packets when used together with other txonly.
>> Signed-off-by: Chengwen Feng <fengchengwen@huawei.com>
>> Signed-off-by: Lijun Ou <oulijun@huawei.com>
>> ---
>> V1->V2:
>> - use Tx instead of TX
>> - add note in doc
>> ---
>>   app/test-pmd/cmdline.c                      | 91 
>> +++++++++++++++++++++++++++++
>>   doc/guides/rel_notes/release_21_05.rst      |  2 +
>>   doc/guides/testpmd_app_ug/testpmd_funcs.rst | 11 ++++
>>   3 files changed, 104 insertions(+)
>>
>> diff --git a/app/test-pmd/cmdline.c b/app/test-pmd/cmdline.c
>> index 14110eb..4df0c32 100644
>> --- a/app/test-pmd/cmdline.c
>> +++ b/app/test-pmd/cmdline.c
>> @@ -36,6 +36,7 @@
>>   #include <rte_pci.h>
>>   #include <rte_ether.h>
>>   #include <rte_ethdev.h>
>> +#include <rte_ethdev_driver.h>
> 
> This header for PMDs to include, applications shouldn't include this, 
> including this means you are accessing dpdk internals which you 
> shouldn't access.
> 
Thanks. I will fix it.
>>   #include <rte_string_fns.h>
>>   #include <rte_devargs.h>
>>   #include <rte_flow.h>
>> @@ -675,6 +676,9 @@ static void cmd_help_long_parsed(void *parsed_result,
>>               "set port (port_id) ptype_mask (ptype_mask)\n"
>>               "    set packet types classification for a specific 
>> port\n\n"
>> +            "tx_done_cleanup (port_id) (queue_id) (free_cnt)\n"
>> +            "    Cleanup a Tx queue's mbuf on a port\n\n"
>> +
>>               "set port (port_id) queue-region region_id (value) "
>>               "queue_start_index (value) queue_num (value)\n"
>>               "    Set a queue region on a port\n\n"
>> @@ -16910,6 +16914,92 @@ cmdline_parse_inst_t cmd_showport_macs = {
>>       },
>>   };
>> +/* *** tx_done_cleanup *** */
>> +struct cmd_tx_done_cleanup_result {
>> +    cmdline_fixed_string_t clean;
>> +    cmdline_fixed_string_t port;
>> +    uint16_t port_id;
>> +    uint16_t queue_id;
>> +    uint32_t free_cnt;
>> +};
>> +
>> +static void
>> +cmd_tx_done_cleanup_parsed(void *parsed_result,
>> +               __rte_unused struct cmdline *cl,
>> +               __rte_unused void *data)
>> +{
>> +    struct cmd_tx_done_cleanup_result *res = parsed_result;
>> +    struct rte_eth_dev *dev;
>> +    uint16_t port_id = res->port_id;
>> +    uint16_t queue_id = res->queue_id;
>> +    uint32_t free_cnt = res->free_cnt;
>> +    int ret;
>> +
>> +    if (!rte_eth_dev_is_valid_port(port_id)) {
>> +        printf("Invalid port_id %u\n", port_id);
>> +        return;
>> +    }
>> +
>> +    dev = &rte_eth_devices[port_id];
> 
> Similar to above comment 'rte_eth_devices' is the internal variable, 
> applications should not access it directly.
> 
No API is available, and multiple references exist in the testpmd file.
>> +    if (queue_id >= dev->data->nb_tx_queues) {
>> +        printf("Invalid Tx queue_id %u\n", queue_id);
>> +        return;
>> +    }
>> +
> 
> Number of the queues can be get via 'rte_eth_dev_info_get()'.
> 
This is also called in txonly. Do you want to replace it?
>> +    if (dev->data->tx_queue_state[queue_id] !=
>> +        RTE_ETH_QUEUE_STATE_STARTED) {
>> +        printf("Tx queue_id %u not started!\n", queue_id);
>> +        return;
>> +    }
>> +
> 
> I am not sure if we have an API to get this information, if there is a 
> need from application to get this data we should consider adding a new 
> API. cc'ed Andrew and Thomas.
> 
>> +    /*
>> +     * rte_eth_tx_done_cleanup is a dataplane API, user must make sure
>> +     * there are no concurrent access to the same Tx queue (like
>> +     * rte_eth_tx_burst, rte_eth_dev_tx_queue_stop and so on) when 
>> this API
>> +     * called.
>> +     */
>> +    ret = rte_eth_tx_done_cleanup(port_id, queue_id, free_cnt);
>> +    if (ret < 0) {
>> +        printf("Failed to cleanup mbuf for port %u Tx queue %u "
>> +               "error desc: %s(%d)\n",
>> +               port_id, queue_id, strerror(-ret), ret);
>> +        return;
>> +    }
>> +
>> +    printf("Cleanup port %u Tx queue %u mbuf nums: %u\n",
>> +           port_id, queue_id, ret);
>> +}
>> +
>> +cmdline_parse_token_string_t cmd_tx_done_cleanup_clean =
>> +    TOKEN_STRING_INITIALIZER(struct cmd_tx_done_cleanup_result, clean,
>> +                 "tx_done_cleanup");
>> +cmdline_parse_token_string_t cmd_tx_done_cleanup_port =
>> +    TOKEN_STRING_INITIALIZER(struct cmd_tx_done_cleanup_result, port,
>> +                 "port");
>> +cmdline_parse_token_num_t cmd_tx_done_cleanup_port_id =
>> +    TOKEN_NUM_INITIALIZER(struct cmd_tx_done_cleanup_result, port_id,
>> +                  UINT16);
>> +cmdline_parse_token_num_t cmd_tx_done_cleanup_queue_id =
>> +    TOKEN_NUM_INITIALIZER(struct cmd_tx_done_cleanup_result, queue_id,
>> +                  UINT16);
>> +cmdline_parse_token_num_t cmd_tx_done_cleanup_free_cnt =
>> +    TOKEN_NUM_INITIALIZER(struct cmd_tx_done_cleanup_result, free_cnt,
>> +                  UINT32);
>> +
>> +cmdline_parse_inst_t cmd_tx_done_cleanup = {
>> +    .f = cmd_tx_done_cleanup_parsed,
>> +    .data = NULL,
>> +    .help_str = "tx_done_cleanup port <port_id> <queue_id> <free_cnt>",
>> +    .tokens = {
>> +        (void *)&cmd_tx_done_cleanup_clean,
>> +        (void *)&cmd_tx_done_cleanup_port,
>> +        (void *)&cmd_tx_done_cleanup_port_id,
>> +        (void *)&cmd_tx_done_cleanup_queue_id,
>> +        (void *)&cmd_tx_done_cleanup_free_cnt,
>> +        NULL,
>> +    },
>> +};
>> +
>>   /* 
>> ******************************************************************************** 
>> */
>>   /* list of instructions */
>> @@ -17035,6 +17125,7 @@ cmdline_parse_ctx_t main_ctx[] = {
>>       (cmdline_parse_inst_t *)&cmd_config_rss_reta,
>>       (cmdline_parse_inst_t *)&cmd_showport_reta,
>>       (cmdline_parse_inst_t *)&cmd_showport_macs,
>> +    (cmdline_parse_inst_t *)&cmd_tx_done_cleanup,
>>       (cmdline_parse_inst_t *)&cmd_config_burst,
>>       (cmdline_parse_inst_t *)&cmd_config_thresh,
>>       (cmdline_parse_inst_t *)&cmd_config_threshold,
>> diff --git a/doc/guides/rel_notes/release_21_05.rst 
>> b/doc/guides/rel_notes/release_21_05.rst
>> index 23f7f0b..8077573 100644
>> --- a/doc/guides/rel_notes/release_21_05.rst
>> +++ b/doc/guides/rel_notes/release_21_05.rst
>> @@ -69,6 +69,8 @@ New Features
>>     * Added command to display Rx queue used descriptor count.
>>       ``show port (port_id) rxq (queue_id) desc used count``
>> +  * Added command to cleanup a Tx queue's mbuf on a port.
>> +    ``tx_done_cleanup port <port_id> <queue_id> <free_cnt>``
>>   Removed Items
>> diff --git a/doc/guides/testpmd_app_ug/testpmd_funcs.rst 
>> b/doc/guides/testpmd_app_ug/testpmd_funcs.rst
>> index f59eb8a..fa49e58 100644
>> --- a/doc/guides/testpmd_app_ug/testpmd_funcs.rst
>> +++ b/doc/guides/testpmd_app_ug/testpmd_funcs.rst
>> @@ -272,6 +272,17 @@ and ready to be processed by the driver on a 
>> given RX queue::
>>      testpmd> show port (port_id) rxq (queue_id) desc used count
>> +cleanup txq mbufs
>> +~~~~~~~~~~~~~~~~~~~~~~~~
>> +
>> +Request the driver to free mbufs currently cached by the driver for a 
>> given port's
>> +Tx queue::
>> +   testpmd> tx_done_cleanup port (port_id) (queue_id) (free_cnt)
>> +
>> +.. note::
>> +   This command is dangerous, users must make sure there are no 
>> cucurrent access to
>> +   the same Tx queue (link rte_eth_tx_burst, 
>> rte_eth_dev_tx_queue_stop and so on).
>> +
>>   show config
>>   ~~~~~~~~~~~
>>
> 
> .
>