Re: [PATCH] numa: Add missing \n to error message

[Laurent Vivier <laurent@vivier.eu>]

Le 06/11/2019 à 17:55, Markus Armbruster a écrit :
> Greg Kurz <groug@kaod.org> writes:
> 
>> On Wed, 6 Nov 2019 14:01:01 +0100
>> Laurent Vivier <laurent@vivier.eu> wrote:
>>
>>> Le 06/11/2019 à 13:46, Greg Kurz a écrit :
>>>> If memory allocation fails when using -mem-path, QEMU is supposed to print
>>>> out a message to indicate that fallback to anonymous RAM is deprecated. This
>>>> is done with error_printf() which does output buffering. As a consequence,
>>>> the message is only printed at the next flush, eg. when quiting QEMU, and
>>>> it also lacks a trailing newline:
>>>>
>>>> qemu-system-ppc64: unable to map backing store for guest RAM: Cannot allocate memory
>>>> qemu-system-ppc64: warning: falling back to regular RAM allocation
>>>> QEMU 4.1.50 monitor - type 'help' for more information
>>>> (qemu) q
>>>> This is deprecated. Make sure that -mem-path  specified path has sufficient resources to allocate -m specified RAM amountgreg@boss02:~/Work/qemu/qemu-spapr$
>>>>
>>>> Add the missing \n to fix both issues.
>>>>
>>>> Fixes: cb79224b7e4b "deprecate -mem-path fallback to anonymous RAM"
>>>> Signed-off-by: Greg Kurz <groug@kaod.org>
>>>> ---
>>>>  hw/core/numa.c |    2 +-
>>>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>>>
>>>> diff --git a/hw/core/numa.c b/hw/core/numa.c
>>>> index 038c96d4abc6..e3332a984f7c 100644
>>>> --- a/hw/core/numa.c
>>>> +++ b/hw/core/numa.c
>>>> @@ -503,7 +503,7 @@ static void allocate_system_memory_nonnuma(MemoryRegion *mr, Object *owner,
>>>>              warn_report("falling back to regular RAM allocation");
>>>>              error_printf("This is deprecated. Make sure that -mem-path "
>>>>                           " specified path has sufficient resources to allocate"
>>>> -                         " -m specified RAM amount");
>>>> +                         " -m specified RAM amount\n");
>>>>              /* Legacy behavior: if allocation failed, fall back to
>>>>               * regular RAM allocation.
>>>>               */
>>>>
>>>>
>>>
>>> Why is this an error_printf() and not an error_report()?
>>>
>>
>> Because CODING_STYLE suggests to do so I guess:
>>
>> Reporting errors to the human user
>> ----------------------------------
>>
>> Do not use printf(), fprintf() or monitor_printf().  Instead, use
>> error_report() or error_vreport() from error-report.h.  This ensures the
>> error is reported in the right place (current monitor or stderr), and in
>> a uniform format.
>>
>> Use error_printf() & friends to print additional information. <===
> 
> You're right.
> 
> Since I have nothing queued up right now, I'd prefer to have this go via
> qemu-trivial.

Ok, I will take it in my next qemu-trivial pull request (with the other
Greg's patch).

Thanks,
Laurent