Re: [dpdk-dev] [PATCH] app: fix redundant comparison

[Andrew Rybchenko <andrew.rybchenko@oktetlabs.ru>]

On 4/19/21 3:44 PM, David Hunt wrote:
> Hi Connor,
> 
> On 19/4/2021 1:29 PM, Min Hu (Connor) wrote:
>> The return value of 'rte_eal_cleanup' is always zero, so comparison
>> with zero is redundant.
>>
>> This patch fixed it by deleting the redundant comparison.
>>
>> Fixes: 67684d1e87b6 ("app/procinfo: call EAL cleanup before exit")
>> Fixes: b68a82425da4 ("app/compress-perf: add performance measurement")
>> Fixes: 5e516c89830a ("app/testpmd: call cleanup on exit")
>> Fixes: 613ce6691c0d ("examples/l3fwd-power: implement proper shutdown")
>> Fixes: 48be180de631 ("eal: move OS common debug functions to single 
>> file")
>> Cc: stable@dpdk.org
>>
>> Signed-off-by: Min Hu (Connor) <humin29@huawei.com>
>> ---
>>   app/pdump/main.c                         | 4 +---
>>   app/proc-info/main.c                     | 4 +---
>>   app/test-compress-perf/main.c            | 7 +------
>>   app/test-pmd/testpmd.c                   | 5 +----
>>   examples/l3fwd-power/main.c              | 3 +--
>>   lib/librte_eal/common/eal_common_debug.c | 4 +---
>>   6 files changed, 6 insertions(+), 21 deletions(-)
>>
>> diff --git a/app/pdump/main.c b/app/pdump/main.c
>> index 63bbe65..33523c5 100644
>> --- a/app/pdump/main.c
>> +++ b/app/pdump/main.c
>> @@ -1014,9 +1014,7 @@ main(int argc, char **argv)
>>       /* dump debug stats */
>>       print_pdump_stats();
>> -    ret = rte_eal_cleanup();
>> -    if (ret)
>> -        printf("Error from rte_eal_cleanup(), %d\n", ret);
>> +    rte_eal_cleanup();
>>       return 0;
>>   }
>> diff --git a/app/proc-info/main.c b/app/proc-info/main.c
>> index b9587f7..9498490 100644
>> --- a/app/proc-info/main.c
>> +++ b/app/proc-info/main.c
>> @@ -1458,9 +1458,7 @@ main(int argc, char **argv)
>>       RTE_ETH_FOREACH_DEV(i)
>>           rte_eth_dev_close(i);
>> -    ret = rte_eal_cleanup();
>> -    if (ret)
>> -        printf("Error from rte_eal_cleanup(), %d\n", ret);
>> +    rte_eal_cleanup();
>>       return 0;
>>   }
>> diff --git a/app/test-compress-perf/main.c 
>> b/app/test-compress-perf/main.c
>> index cc9951a..03ee385 100644
>> --- a/app/test-compress-perf/main.c
>> +++ b/app/test-compress-perf/main.c
>> @@ -474,12 +474,7 @@ main(int argc, char **argv)
>>           /* fallthrough */
>>       case ST_CLEAR:
>>       default:
>> -        i = rte_eal_cleanup();
>> -        if (i) {
>> -            RTE_LOG(ERR, USER1,
>> -                "Error from rte_eal_cleanup(), %d\n", i);
>> -            ret = i;
>> -        }
>> +        rte_eal_cleanup();
>>           break;
>>       }
>>       return ret;
>> diff --git a/app/test-pmd/testpmd.c b/app/test-pmd/testpmd.c
>> index d4be23f..1f8a7b8 100644
>> --- a/app/test-pmd/testpmd.c
>> +++ b/app/test-pmd/testpmd.c
>> @@ -3972,10 +3972,7 @@ main(int argc, char** argv)
>>               return 1;
>>       }
>> -    ret = rte_eal_cleanup();
>> -    if (ret != 0)
>> -        rte_exit(EXIT_FAILURE,
>> -             "EAL cleanup failed: %s\n", strerror(-ret));
>> +    rte_eal_cleanup();
>>       return EXIT_SUCCESS;
>>   }
>> diff --git a/examples/l3fwd-power/main.c b/examples/l3fwd-power/main.c
>> index 0af8810..84464d5 100644
>> --- a/examples/l3fwd-power/main.c
>> +++ b/examples/l3fwd-power/main.c
>> @@ -2914,8 +2914,7 @@ main(int argc, char **argv)
>>               deinit_power_library())
>>           rte_exit(EXIT_FAILURE, "deinit_power_library failed\n");
>> -    if (rte_eal_cleanup() < 0)
>> -        RTE_LOG(ERR, L3FWD_POWER, "EAL cleanup failed\n");
>> +    rte_eal_cleanup();
>>       return 0;
>>   }
>> diff --git a/lib/librte_eal/common/eal_common_debug.c 
>> b/lib/librte_eal/common/eal_common_debug.c
>> index 15418e9..04b1fed 100644
>> --- a/lib/librte_eal/common/eal_common_debug.c
>> +++ b/lib/librte_eal/common/eal_common_debug.c
>> @@ -37,8 +37,6 @@ rte_exit(int exit_code, const char *format, ...)
>>       rte_vlog(RTE_LOG_CRIT, RTE_LOGTYPE_EAL, format, ap);
>>       va_end(ap);
>> -    if (rte_eal_cleanup() != 0)
>> -        RTE_LOG(CRIT, EAL,
>> -            "EAL could not release all resources\n");
>> +    rte_eal_cleanup();
>>       exit(exit_code);
>>   }
> 
> 
> Since the function is defined as "int rte_eal_cleanup(void)" and the 
> documentation says:
> 
>   *  - 0 Successfully released all internal EAL resources.
>   *  - -EFAULT There was an error in releasing all resources.
> 
> We really should check for non zero values. Just because it's currently 
> coded to only return zero may not hold in the future. The code may 
> change in the future to return non-zero values.

+1

I think the patch should be rejected.