On 6/14/2021 10:26 PM, Andrew Rybchenko wrote:

On 6/11/21 1:35 PM, Ferruh Yigit wrote:

quoted

On 6/11/2021 10:19 AM, Andrew Rybchenko wrote:

quoted

On 6/11/21 5:06 AM, Li, Xiaoyun wrote:

quoted

Hi
-----Original Message-----
From: Andrew Rybchenko <redacted>
Sent: Friday, May 28, 2021 00:25
To: Li, Xiaoyun <redacted>
Cc: dev@dpdk.org
Subject: [PATCH] app/testpmd: send failure logs to stderr

Running with stdout suppressed or redirected for further processing 
is very confusing in the case of errors.

Signed-off-by: Andrew Rybchenko <redacted>
---

This patch looks good to me.
But what do you think about make it as a fix and backport to stable 
branches?
Anyway works for me.

I have no strong opinion on the topic.

@Ferruh, what do you think?

Same here, no strong opinion.
Sending errors to 'stderr' looks correct thing to do, but changing 
behavior in
the LTS may cause some unexpected side affect, if it is scripted and 
testpmd
output is parsed etc... For this possibility I would wait for the 
next LTS.

So, I guess all agree that backporting to LTS is a bad idea because of
behaviour change.

As I said in a sub-thread I tend to apply in v21.08 since it is a right
thing to do like a fix, but the fix is not that required to be
backported to change behaviour of LTS releases.

quoted

And because of same reason perhaps a release note can be added.

I'll make v2 with release notes added. Good point.

quoted

Also there is 'TESTPMD_LOG' macro for logs in testpmd, (as well as 
'RTE_LOG'
macro), I don't know if we should switch all logs, including 
'printf', to
'TESTPMD_LOG' macro?
Later stdout/sderr can be managed in rte_log level, instead of any 
specific
logic for the testpmd.

I think fprintf() is a better option for debug tool, since its
messages should not go to syslog etc. It should go to stdout/stderr
regardless of logging configuration and log level settings.

For loging, currently we are using multiple API's in testpmd 
(TESTPMD_LOG, RTE_LOG,  snprintf, printf). I agree with Ferruh, in long 
run we should use single loging mechanism where log_level should decide 
the output stream.

For now fprintf() seems OK, as we can pass the output stream compared to 
printf().

quoted

Even there was a defect for this in the rte_log level, that logs 
should go to
stderr: https://bugs.dpdk.org/show_bug.cgi?id=8

quoted

quoted

Acked-by: Xiaoyun Li <redacted>

Acked-by: Aman Deep Singh <aman.deep.singh@intel.com 
<mailto:aman.deep.singh@intel.com>