Re: [PATCH v1 4/5] util: add qemu_get_host_physmem utility function

[Richard Henderson]

On 7/17/20 7:24 AM, Christian Ehrhardt wrote:
>     > +size_t qemu_get_host_physmem(void)
>     > +{
>     > +#ifdef _SC_PHYS_PAGES
>     > +    long pages = sysconf(_SC_PHYS_PAGES);
>     > +    if (pages > 0) {
>     > +        return pages * qemu_real_host_page_size;
> 
>     The Linux man page warns that this product may overflow so maybe you could
>     return pages here.
> 
> 
> The caller might be even less aware of that than this function - so maybe
> better handle it here.
> How about handling overflows and cutting it to MiB before returning?

Indeed, the caller may be less aware, so we should handle it here.  But I don't
think truncating to MiB helps at all, because again, the caller has to handle
overflow.

Better, I think, to saturate the result to ~(size_t)0 and leave it at that.


r~