On 01/09/2011 10:55 AM, Andy Green wrote: > On 01/08/11 19:59, Somebody in the thread at some point said: > >> (1) I think we're agreed that silence (mode 0, ignore), the current >> default, is probably the worst possible value. >> >> (2) It's going to be really, really hard to [i] identify and [ii] >> convince upstreams to fix all alignment issues. Where alignment traps >> may be data-triggered, it will be nearly impossible to have confidence >> that all corner cases have been tested. >> >> I also think that it's unnecessary to eliminate all alignment issues -- >> in many cases, kernel fixups may actually be cheaper to run than the >> defensive code necessary to avoid them, and hardware fixups are even >> cheaper. Furthermore, running on an armv7 or higher processor won't >> trigger the alignment traps at all, so we won't even know that there are >> issues (just as we don't know, nor care, in an x86 context). >> >> Thus my recommendation that we warn and fix up the alignment, rather >> than warn and produce wrong results. (If you really want to force >> someone to deal with these issues, you'd want warn+signal, and I would >> strongly oppose making that the default). > > Sounds right. The user is going to google why his log is filling with > these warnings if he cares and the problem is bad, and this covers his > code as well as distro code (with the small window where the alignment > policy is still 0 from running init through actually setting the > alignment policy to fix+log if he doesn't know about the kernel parameter). > > If he doesn't use Fedora initscripts, then he's at the mercy of the > kernel default alignment policy of "mangle data silently" but that's not > a Fedora problem. In can, however, see one good argument for warn+signal, and that is that abrt already picks up crashes for reporting so no change would be required there. Also a core dump would be useful to pin down the errors that aren't trivial to reproduce. Gordan _______________________________________________ arm mailing list arm@xxxxxxxxxxxxxxxxxxxxxxx https://admin.fedoraproject.org/mailman/listinfo/arm
