Re: [dpdk-dev] [PATCH] eal: add log to print dpdk version at start

[Singh, Aman Deep]

On 9/2/2021 3:57 PM, Bruce Richardson wrote:

On Thu, Sep 02, 2021 at 11:11:39AM +0100, Ferruh Yigit wrote:

On 9/1/2021 6:12 PM, Stephen Hemminger wrote:

On Wed,  1 Sep 2021 11:48:21 +0530
Aman Singh <aman.deep.si...@intel.com> wrote:

 From the logs it is difficult to get the DPDK version
that was used. So added a debug log to print the same.
The log has been added in eal_init so it gets printed
at startup for any application.

Signed-off-by: Aman Singh <aman.deep.si...@intel.com>
---
  lib/eal/freebsd/eal.c | 2 +-
  lib/eal/linux/eal.c   | 2 +-
  lib/eal/windows/eal.c | 1 +
  3 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/lib/eal/freebsd/eal.c b/lib/eal/freebsd/eal.c
index 6cee5ae369..a14a205f4d 100644
--- a/lib/eal/freebsd/eal.c
+++ b/lib/eal/freebsd/eal.c
@@ -958,7 +958,7 @@ rte_eal_init(int argc, char **argv)
        }

eal_mcfg_complete();

-
+       rte_log(RTE_LOG_DEBUG, RTE_LOGTYPE_EAL, "DPDK version: %s\n", 
rte_version());
        return fctret;
  }

diff --git a/lib/eal/linux/eal.c b/lib/eal/linux/eal.c

index 3577eaeaa4..a50960cc78 100644
--- a/lib/eal/linux/eal.c
+++ b/lib/eal/linux/eal.c
@@ -1332,7 +1332,7 @@ rte_eal_init(int argc, char **argv)
        }

eal_mcfg_complete();

-
+       rte_log(RTE_LOG_DEBUG, RTE_LOGTYPE_EAL, "DPDK version: %s\n", 
rte_version());
        return fctret;
  }

diff --git a/lib/eal/windows/eal.c b/lib/eal/windows/eal.c

index 3d8c520412..5e6d5d8930 100644
--- a/lib/eal/windows/eal.c
+++ b/lib/eal/windows/eal.c
@@ -419,6 +419,7 @@ rte_eal_init(int argc, char **argv)
         */
        rte_eal_mp_remote_launch(sync_func, NULL, SKIP_MAIN);
        rte_eal_mp_wait_lcore();
+       rte_log(RTE_LOG_DEBUG, RTE_LOGTYPE_EAL, "DPDK version: %s\n", 
rte_version());
        return fctret;
  }

NAK
DPDK is already too chatty at startup.

Is it better if the log is 'debug', so it won't be visible by default?
This can be useful to support customers, sometimes when there are multiple
binaries around, it is hard to say version of them.
As Bruce reminded, '-v' eal option provides this feature, which is better than
nothing, but it is not as useful if you are looking to an old log without actual
binary.

If your application needs it then do-it-yourself.

Application may have its own versioning, which can be unrelated to the DPDK
version numbers, this can be useful to get just DPDK version.

I'd also point out that if you have a currently running DPDK binary and
want to know the DPDK version number, just connect to the telemetry socket
and it will tell you e.g.

    $ echo "quit" | sudo ./usertools/dpdk-telemetry.py
    Connecting to /var/run/dpdk/rte/dpdk_telemetry.v2
    {"version": "DPDK 21.11.0-rc0", "pid": 134894, "max_output_len": 16384}
    -->

    $


/Bruce

Considering the EAL "-v" option which does the same job as this patch.
Planning to drop this change for now.

Thanks
Aman