On 10/30/2014 09:55 AM, Eric Blake wrote:
On 10/30/2014 09:49 AM, Martin Kletzander wrote:
> The value is stored in unsigned long long, so ULLONG_MAX is the proper
> upper limit to use.
No, it's not.
>
> Signed-off-by: Martin Kletzander <mkletzan(a)redhat.com>
> ---
> Even though this is a build-breaker (for 32bit systems
> memtune-unlimited fails to parse), I'm not pushing it as one because
> it feels odd that such change wouldn't break anything else.
What's the compile failure? This patch is intentionally trying to fit
the largest value that will fit in an unsigned long when scaled by
kilobytes, while still parsing by bytes. Thus, on 64-bit machines, you
can parse 0xffffffffffffffff bytes, then scale down by 1024 and store in
unsigned long; on 32-bit machines, your maximum has to be limited to
0xffffffff*1024 bytes before scaling back down.
Sounds like the real bug is in the memtune-unlimited test. 2^53-1 is
the maximum memory for a 64-bit host, but invalid on a 32-bit host. Any
interface that uses 'unsigned long' as its capping point has to have
different maximum limits on 32-bit hosts.
--
Eric Blake eblake redhat com +1-919-301-3266
Libvirt virtualization library
http://libvirt.org