[PATCH v2 2/3] eal: fix trace init fail with long file-prefix

[David Marchand]

On Tue, Jun 14, 2022 at 8:06 AM Chengwen Feng <fengchengwen at huawei.com> wrote:
>
> Bug scenario:
> 1. start testpmd:
> dpdk-testpmd -l 4-6 -a 0000:7d:00.0 --trace=.* \
> -file-prefix=trace_autotest -- -i
> 2. then observed:
> EAL: eal_trace_init():94 failed to initialize trace [File exists]

This is not directly related to the issue being fixed, but this error
log is really obscure..
Can we enhance this, maybe in a followup patch?


> EAL: FATAL: Cannot init trace
> EAL: Cannot init trace
> EAL: Error - exiting with code: 1
>
> The root cause it that the offset set wrong with long file-prefix and
> then lead the strftime return failed.
>
> Fixes: 321dd5f8fa62 ("trace: add internal init and fini interface")
> Cc: stable at dpdk.org
>
> Signed-off-by: Chengwen Feng <fengchengwen at huawei.com>

Reviewed-by: David Marchand <david.marchand at redhat.com>


And another topic, I see no reason for the limitation/truncation on
the file prefix.
Testing with the last patch of the series, I can see odd directory, like
EAL: Trace dir:
/home/dmarchan/builds/main/build-gcc-shared/app/test/trace_autot-2022-06-15-PM-03-18-39
I'll send a cleanup series for this, later.


-- 
David Marchand