Messages in this thread | | | Date | Thu, 29 Jan 2015 16:53:52 -0500 | From | Rik van Riel <> | Subject | Re: [PATCH 2/3] x86, fpu: unlazy_fpu: don't do __thread_fpu_end() if use_eager_fpu() |
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On 01/29/2015 04:49 PM, Oleg Nesterov wrote:
> Yes. But in this case tsk != current, and we ensure that __switch_to() > was finished. wait_task_inactive(). > >> When we switch to the traced task, the __thread_fpu_end() >> that was called from init_fpu() ensures that >> switch_fpu_begin() will actually load the new FPU state >> from memory into the registers, and we will not take >> the fpu_lazy_restore() branch. > > No. in this case we rely on "tsk->thread.fpu.last_cpu = ~0" which disables > fpu_lazy_restore().
I should have known that.
Especially considering I have a patch here that converts "tsk->thread.fpu.last_cpu = ~0" into a disable_lazy_restore() call...
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