On Mon, Jul 18, 2016 at 03:37:46PM +1000, Dave Chinner wrote: > > The reason I did this in the first place was a vague notion that unconditional > > packing was harmful. > > > > http://digitalvampire.org/blog/index.php/2006/07/31/why-you-shouldnt-use-__attribute__packed/ > > > > "However, it's actively harmful to add the attribute to a structure that's > > already going to be laid out with no padding." > > ... > > "gcc gets scared about unaligned accesses and generates six times as much code > > (96 bytes vs. 16 bytes)! sparc64 goes similarly crazy, bloating from 12 bytes > > to 52 bytes" > > > > I don't know if that's (still) correct or not, but that was the reason > > for the selective __pack application way back when. Might be worth > > investigating? > > Christoph? The first two ptches are fine, but more info is needed > for this one... I don't have a sparc64 compiler to test unfortunately. But I can confirm that on x86-64 xfs.o is bit to bit identical with or without the patch. _______________________________________________ xfs mailing list xfs@xxxxxxxxxxx http://oss.sgi.com/mailman/listinfo/xfs
