Messages in this thread | | | Subject | Re: [PATCHv11 2.6.36-rc2-tip 3/15] 3: uprobes: Slot allocation for Execution out of line(XOL) | From | Peter Zijlstra <> | Date | Mon, 06 Sep 2010 20:20:24 +0200 |
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On Mon, 2010-09-06 at 23:29 +0530, Srikar Dronamraju wrote: > > Lets say the thread while singlestepping the process gets > pre-empted. Eventually the cpu might run some other thread of the same > process before picking the first run thread. Or the first run > thread could after migration due to load balancing or whatever end up > running on a different thread? How do we handle these cases?
So assuming we're preempted while the IP is inside the slot:
On the preempt-out we store the slot relative ip (ip - start_of_slot), on preempt-in we write the replacement instructions in our cpu slot (could be the same cpu, could be another) and re-position the ip to point to the same relative position inside that slot, then go!
It really doesn't matter what happens in between.
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