Re: [libvirt] [PATCH] openvz: Fix wordsize on 64 bit architectures

On 06/19/2012 04:40 PM, Eric Blake wrote: > On 06/19/2012 01:11 AM, Guido Günther wrote: >> On Mon, Jun 18, 2012 at 03:08:39PM -0600, Eric Blake wrote: >>>> On 06/17/2012 11:18 AM, Guido Günther wrote: >>>>>> The word size there is 64 bit not 8. > >>>> Do we ever compile openvz on any platform where sizeof(int) = 4? >>>> Shouldn't this really be checking sizeof(long)? >> Or the actual pointer size? Patch attached. > > Well, on the new i32 kernel ABI for 64-bit platforms, sizeof(void*)==4 > while sizeof(long)==8; on the other hand, for mingw64, sizeof(void*)==8 > while sizeof(long)==4. You can't win for all platforms, but for the > case of openvz, it seems like we are more likely to be compiled on Linux > where sizeof(long) may indeed be the better choice. > > But I'm okay with your patch to use void*, since the i32 ABI is not > popular yet. Correction - the x32 ABI; as mentioned here: http://kernelnewbies.org/LinuxChanges#head-ec7868ff102658ddea67d09dcedb4a... has sizeof(long)==4 to match sizeof(void*), so sizeof(void*) is reasonable after all. > >> +++ b/src/openvz/openvz_conf.c >> @@ -195,7 +195,7 @@ virCapsPtr openvzCapsInit(void) >> if ((guest = virCapabilitiesAddGuest(caps, >> "exe", >> utsname.machine, >> - sizeof(int) == 4 ? 32 : 64, >> + sizeof(void*) == 4 ? 32 : 64, > > ACK. Thus void* really is better than long here.