On 12.10.2011, at 23:19, Stefan Weil wrote: > Am 12.10.2011 22:47, schrieb Alexander Graf: >> Well, yes, my point is that it's a bug in valgrind that should be fixed. I >> don't think we should special-case QEMU because of bugs in debugging >> software :) >> >> Alex > > Yes, the valgrind bug should be fixed. I don't know why it isn't, > but that's not the point: > > Valgrind is very valuable for finding certain kinds of bugs in QEMU > which we want to find and fix (I hope we agree on this). > Therefore developers should be able to use it. > > Today, they cannot use Valgrind with QEMU out-of-the box, > because they get an assertion. Some developers will stop here. > Others will ask Google, look in Valgrind's code and spend some > time to find and fix the problem before they start using > Valgrind to find QEMU bugs. > > They could have spent their time better. > > I can try to make QEMU more useable with Valgrind by changing > the QEMU code (which was Valgrind compatible up to Avi's change). > > I cannot change the Valgrind code, and even if I could, it would > take a lot of time until all Linux distributions would include a > fixed Valgrind :-( > > If all existing gdb versions did not work with QEMU, > but there were a simple QEMU change which made them work, > what would you do?
I would add a command line option to modify the alignment in runtime, defaulting it to something sane (16MB), so you can work around bugs in vagrind with a simple parameter :) Alex