Am Mittwoch 25 Februar 2009 10:36:24 schrieb Pauli Nieminen: > Attached patch fixes freeze if r200 driver makes debug output to > terminal. It also makes dri driver crash instead of silent exist when > there is fatal error. > > Basic idea is to call special debug output function instead of > fprintf. This debug function then checks if hardware lock is held. If > lock is held output is queued to linked list. UNLOCK_HARDWARE then > calls debug function that outputs all queued messages. > > Patch also changes all exit calls to UNLOCK_HARDWARE(); abort(); > combination so it is easier to get backtrace if facing bug in driver > code. > > This code is nowhere near production quality but it is enough to test > that idea works and I can do "R200_DEBUG=all glxgears" in terminal > without freeze. Also I tested 3D Mark 2001 SE (without r200 debug) in > wine so this shouldn't have caused regression. > > What should be still done? > - Make this functionality shared between dri drivers > - Thread safety? r200DebugPrintf is not safe if application uses > opengl from multiple threads.
Actually, an OpenGL context must not be used from multiple threads at the same time. So as long as the output queue is per-context, there shouldn't be a problem. > - Optimized memory handling. -- Calling twice malloc for each message > can't be correct. :) Actually, there are significantly worse problems in the code. Using vsprintf is absolutely incorrect and will cause additional bugs down the line. Also, the writen < 0 check is incorrect. Please read the manpage for vsnprintf for details on how to do this kind of code correctly. > - Better error handling. -- There is still some error handling missing > - Make assert also call unlock_hardware before abort I'm wondering - shouldn't the DRM automatically release the lock if a client exits? I was under the impression that this was already done, but if not, it is definitely a kernel bug that needs fixing. Sprinkling unlock_hardwares in the userspace code is the wrong approach, because it won't help e.g. in the case of segfaults. cu, Nicolai ------------------------------------------------------------------------------ Open Source Business Conference (OSBC), March 24-25, 2009, San Francisco, CA -OSBC tackles the biggest issue in open source: Open Sourcing the Enterprise -Strategies to boost innovation and cut costs with open source participation -Receive a $600 discount off the registration fee with the source code: SFAD http://p.sf.net/sfu/XcvMzF8H _______________________________________________ Mesa3d-dev mailing list Mesa3d-dev@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/mesa3d-dev
