On 01/07/2011 05:25 PM, Andy Green wrote: > On 01/07/11 17:17, Somebody in the thread at some point said: > >>> No, it's not the same issue. >>> >>> On x86 as described on your link, it's just a performance penalty if >>> your members are not aligned. On ARM without fixup, you read actual >>> garbage as described on my article. >> >> Yup, I was more referring to the data not aligning when unioning > > That's nothing to do with this issue. > > With this issue, a correct structure in a typedef or a struct with > correct alignment padding turns to crap because the structure pointed to > is not on a u32 boundary for example.
I see. But shouldn't the compiler be taking care of that? -malign? >> And these alignment error counters (I'm assuming that is what those >> large numbers in /proc/cpu/alignment are) - do they implicitly mean >> actual calculation errors? Or are they generally harmless? I ask because > > They're not harmless if you don't fix them up and you're going to use > the misaligned data for something: the data is corrupted. If you read > the data and didn't do anything important with it then you won't see any > problem. > > What gcc did you cook your kernel with? The F12 repository kernel. I am currently building a new one (needed a few extra options) with the F13 gcc and bintools. But all these errors appear to be under User rather than System, so is it really the kernel? Since over the past hour of kernel recompiling the counters haven't increased at all, my guess is that it all happened last night when I was building/testing dietlibc stuff. I'll test that hypothesis when the new kernel is built. Gordan _______________________________________________ arm mailing list arm@lists.fedoraproject.org https://admin.fedoraproject.org/mailman/listinfo/arm