Re: [PATCH v6 26/27] util: add support for formatting thread info in messages

[Markus Armbruster <armbru@redhat.com>]

Daniel P. Berrangé <berrange@redhat.com> writes:

> The message context is now extended to be able to include the
> thread ID and thread name, after the program name. On Linux
> the thread ID will match the process TID visible in /proc,
> while on other platforms it will merely be an integer repr
> of the system thread object address/ID.
>
> This changes the output for both error_report and qemu_log,
> when running under the system emulators or the QEMU storage
> daemon.

Yes:

    $ qemu-system-x86_64 -object tls-creds-x509,id=t0
    qemu-system-x86_64: (1116063:main): Missing 'dir' property value

I do not like this change.  The part in (parenthesis) is gobbledygook
for non-developers.  I feel it should be off by default.

Making it on by default for log message (as shown below) is fine.

>         Other programs omit the thread information since
> they are largely single threaded, though potentially it
> would be useful to enable in all of them, given that the RCU
> thread will always get spawned by a constructor function.
>
> Before:
>
>   # qemu-system-x86_64 -object tls-creds-x509,id=t0,dir=fish -d 'trace:qcrypto*'
>   qemu-system-x86_64: qcrypto_tls_creds_x509_load TLS creds x509 load creds=0x560db818e080 dir=fish
>   qemu-system-x86_64: qcrypto_tls_creds_get_path TLS creds path creds=0x560db818e080 filename=ca-cert.pem path=<none>
>   qemu-system-x86_64: Unable to access credentials fish/ca-cert.pem: No such file or directory
>
> After:
>
>   # qemu-system-x86_64 -object tls-creds-x509,id=t0,dir=fish -d 'trace:qcrypto*'
>   qemu-system-x86_64: (772366:main): qcrypto_tls_creds_x509_load TLS creds x509 load creds=0x560db818e080 dir=fish
>   qemu-system-x86_64: (772366:main): qcrypto_tls_creds_get_path TLS creds path creds=0x560db818e080 filename=ca-cert.pem path=<none>
>   qemu-system-x86_64: (772366:main): Unable to access credentials fish/ca-cert.pem: No such file or directory
>
> The '-msg thread-info=on|off' argument is introduced to allow this
> new default output to be supressed if desired.
>
> Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
> Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>