Re: [PATCH] xen/arm: Print memory size in decimal in construct_domU

[Julien Grall <julien@xxxxxxx>]

Hi Michal,

On 03/01/2023 09:39, Michal Orzel wrote:
> On 03/01/2023 10:21, Ayan Kumar Halder wrote:
> > Hi Michal,
> >
> > On 02/01/2023 14:49, Michal Orzel wrote:
> > > Printing domain's memory size in hex without even prepending it
> > > with 0x is not very useful and can be misleading. Switch to decimal
> > > notation.
> > >
> > > Signed-off-by: Michal Orzel <michal.orzel@xxxxxxx>
> > > ---
> > >    xen/arch/arm/domain_build.c | 2 +-
> > >    1 file changed, 1 insertion(+), 1 deletion(-)
> > >
> > > diff --git a/xen/arch/arm/domain_build.c b/xen/arch/arm/domain_build.c
> > > index 829cea8de84f..7e204372368c 100644
> > > --- a/xen/arch/arm/domain_build.c
> > > +++ b/xen/arch/arm/domain_build.c
> > > @@ -3774,7 +3774,7 @@ static int __init construct_domU(struct domain *d,
> > >        if ( rc != 0 )
> > >            return rc;
> > >
> > > -    printk("*** LOADING DOMU cpus=%u memory=%"PRIx64"KB ***\n", d->max_vcpus, 
> > > mem);
> > > +    printk("*** LOADING DOMU cpus=%u memory=%"PRIu64"KB ***\n", d->max_vcpus, 
> > > mem);
> > I will prefer it to be printed in hex format with 0x prefixed. The
> > reason being the mem is obtained from device-tree domU's 'memory' prop
> > where the values are in hex.
> No, I cannot agree. Refer to booting.txt documentation:
> "A 64-bit integer specifying the amount of kilobytes of RAM to allocate to the 
> guest."
> Also note that in the provided examples, we are using the decimal values.
> All in all it does not matter the notation, you can provide e.g. "memory = 131072;" or 
> "memory = 0x20000".
> I find it a bit odd to print e.g. 0x20000KB and decimal is easier to read.
By easier, do you mean you can easily figure out how much memory in 
GB/MB/KB you gave to the guest? If so, then I have to disagree. Without 
a calculator, I will find quicker the split.
If you want to print in decimal, then I think we should split the amount 
in GB/MB/KB. Otherwise, we should stick in hexadecimal (so add 0x).
Cheers,

--
Julien Grall