On Wed, 6 Nov 2019 14:01:01 +0100
Laurent Vivier <laur...@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 <gr...@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. <===
error_report() prints the current location. In certain common cases
like command line parsing, the current location is tracked
automatically. To manipulate it manually, use the loc_``*``() from
error-report.h.
> Thanks,
> Laurent
>
