On 28 March 2017 at 10:36, Michel Dänzer <michel at daenzer.net> wrote: > On 28/03/17 05:24 PM, Julien Isorce wrote: > > Hi Michel, > > > > About the hard lockup, I noticed that I cannot have it with the > > following conditions: > > > > 1. soft lockup fix (the 0->i change which avoids infinite loop) > > 2. Your suggestion: (!(rbo->flags & RADEON_GEM_CPU_ACCESS) > > 3. radeon.gartsize=512 radeon.vramlimit=1024 (any other values above do > > not help, for example (1024, 1024) or (1024, 2048)) > > > > Without 1 and 2, but with 3, our test reproduces the soft lockup (just > > discovered few days ago). > > Without 3 (and with or without 1., 2.), our test reproduces the hard > > lockup which one does not give any info in kern.log (sometimes some NUL > > ^@ characters but not always). > > What exactly does "hard lockup" mean? What are the symptoms? > > Screens are frozen, cannot ssh, no mouse/keyboard, no kernel panic. Requires hard reboot. After reboot, nothing in /var/crash, nothing in /sys/fs/pstore, nothing in kern.log except sometimes some nul characters ^@. Adding traces it looks like the test app was still in a ioctl(RADEON_CS) but it is difficult to rely on that since this is called a lot. Using a serial console did not show additional debug messages. kgdb was not useful but probably worth another attempt. -------------- next part -------------- An HTML attachment was scrubbed... URL: <https://lists.freedesktop.org/archives/amd-gfx/attachments/20170328/77ecae6e/attachment-0001.html>
