Heikki Lindholm kirjoitti:
Xenomai might preempt linux when linux has cleared a tasks MSR_FP, but not yet set last_task_used_math to NULL. As a result the tasks MSR_FP will get set, although it should be cleared. If the task happens to hit one of the codepaths that save FPU state if MSR_FP is set, the wrong FPU state might be saved to the task. The attached patch should fix this. I couldn't try it on most recent Xenomai trunk, because latency wouldn't build anymore. However, I see no reason it shouldn't work. All thee having trouble with X and Xenomai, give this a shot.

Additionally, there's also a Linux bug, which might cause corruption in 2.6.14 PREEMPT:

http://www.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=9f232a125bf86b0dae09f8ea4a0553535cf6b658

For solid performance that should also be applied on top of the I-pipe patch.

-- Heikki Lindholm

_______________________________________________
Xenomai-core mailing list
Xenomai-core@gna.org
https://mail.gna.org/listinfo/xenomai-core

Reply via email to