Subject: 2.6.15-rt17
Newsgroups: gmane.linux.kernel
Date: 2006-02-21 15:55:48 GMT (3 years, 19 weeks, 1 day, 9 hours and 49 minutes ago)
i have released the 2.6.15-rt17 tree, which can be downloaded from the usual place: http://redhat.com/~mingo/realtime-preempt/ lots of changes all across the map. There are several bigger changes: the biggest change is the new PI code from Esben Nielsen, Thomas Gleixner and Steven Rostedt. This big rework simplifies and streamlines the PI code, and fixes a couple of bugs and races: - only the top priority waiter on a lock is enqueued into the pi_list of the task which holds the lock. No more pi list walking in the boost case. - simpler locking rules - fast Atomic acquire for the non contended case and atomic release for non waiter case is fully functional now - use task_t references instead of thread_info pointers - BKL handling for semaphore style locks changed so that BKL is dropped before the scheduler is entered and reaquired in the return path. This solves a possible deadlock situation in the BKL reacquire path of the scheduler. another change is the reworking of the SLAB code: it now closely matches the upstream SLAB code, and it should now work on NUMA systems too (untested though). the tasklet code was reworked too to be PREEMPT_RT friendly: the new PI code unearthed a fundamental livelock scenario with PREEMPT_RT, and the fix was to rework the tasklet code to get rid of the 'retrigger softirqs' approach. other changes: various hrtimers fixes, latency tracer enhancements - and more. (Robust-futexes are not expected to work in this release.) please report any new breakages, and re-report any old breakages as well. to build a 2.6.15-rt17 tree, the following patches should be applied: http://kernel.org/pub/linux/kernel/v2.6/linux-2.6.15.tar.bz2 http://redhat.com/~mingo/realtime-preempt/patch-2.6.15-rt17 Ingo