On Mon, Dec 17, 2012 at 11:22 PM, Alan Coopersmith < [email protected]> wrote:
> On 12/17/12 03:41 AM, Jim Klimov wrote: > > On 2012-12-17 06:59, Alan Coopersmith wrote: > >> Oh, and it assumes no one needs 32-bit binaries any more, since all > Solaris 11 > >> users have to be running the 64-bit kernel since the 32-bit kernel was > EOL'ed. > >> (32-bit libraries are still there for binary compatibility with other > programs, > >> it's just most of the /usr/bin/x* commands converted to 64-bit.) > >> > >> If you care about 32-bit support, that's one more change you'll have to > undo. > > > > Well, I may probably get corrected (and should, if need be) - but > > in such discussions I've always thought (and heard) that these are > > two different things. 64-bit kernel is for optimal harnessing of > > hardware with large (>4gb) memory and perhaps wider instructions > > on CPU. > > > > 64-bit or 32-bit userspace programs is about addressing virtual > > memory again and large files to an extent (AFAIK the latter can > > be used with 32-bit programs too). 64-bit userspace with "small" > > programs like many UNIX command-line tools, GUI applets, etc. > > which don't feasibly need to juggle gigabytes of data at once - > > now, that would also be about wasting RAM and CPU cycles on > > pushing around more bytes of pointers and other increased > > structures with no practical gain. > > > > Am I wrong to maintain this point of view? > > That's mostly correct, but there are other benefits to 64-bit userspace > programs: > > - stdio interfaces in libc support file descriptors > 255 without any > compatibility issues or interface extensions > > - x86 binaries have access to a larger number of registers, often > resulting > in measurably faster performance > Typically true but the new 32-bit ABI changes all that: https://sites.google.com/site/x32abi/ http://en.wikipedia.org/wiki/X32_ABI If Solaris integrates support for this then 32-bit having less pointer overhead compared to 64-bit will continue to hold on x86. However IMHO for a typical large application (as opposed to small utilities), clean support for large files, and no practical heap limitations make 32-bit forgettable. Regards, Moinak. -- ================================ http://moinakg.wordpress.com/ http://moinakg.github.com/pcompress/ _______________________________________________ OpenIndiana-discuss mailing list [email protected] http://openindiana.org/mailman/listinfo/openindiana-discuss
