On 2/27/13 10:38 PM, Eric Sandeen wrote:
> re-cc'ing xfs list
> So I used pahole to look at all structs, objdump -d to disassemble,
> and md5sum'd the results to see what's different.
> pi@raspberrypi ~ $ md5sum cross/*.dis cross/*.pahole native/*.dis
> <manual sort>
> c0abd80c3bf049db5e1909fd851261cc cross/xfs-O1-g.ko.pahole
> c0abd80c3bf049db5e1909fd851261cc cross/xfs-O2-g.ko.pahole
> c0abd80c3bf049db5e1909fd851261cc cross/xfs-Os-g.ko.pahole
> c0abd80c3bf049db5e1909fd851261cc native/xfs-O1-g.ko.pahole
> c0abd80c3bf049db5e1909fd851261cc native/xfs-O2-g.ko.pahole
> c0abd80c3bf049db5e1909fd851261cc native/xfs-Os-g.ko.pahole
> so all structures look identical, good - but:
> while disassembly of these two modules match:
> d76f6ebf4d8a1b9f786facefbcf16f69 cross/xfs-O1-g.ko.dis
> d76f6ebf4d8a1b9f786facefbcf16f69 native/xfs-O1-g.ko.dis
> do you see the problem w/ the cross-compiled xfs-O1-g.ko as well?
> the others differ:
> 349f3490a49f2ce539c2b058914f64f0 native/xfs-Os-g.ko.dis
> 91c8e8230774808b538c21a83106a5d7 cross/xfs-Os-g.ko.dis
> 649338e1b8eeed6a294504fc76a39cb0 native/xfs-O2-g.ko.dis
> e52c2a48277326c313bba76aa0b33ab7 cross/xfs-O2-g.ko.dis
> The diff of the disassembly of the others is huge, hard to
> know where to start just yet. Need an objdump mode that only
> shows function-relative addresses or something to cut down
> on the noise.
Could you try the same, to isolate the differences: objdump -d
all of the *.o files for, say, the -O2 build, md5sum & compare,
and see which ones differ?