2022-08-29 16:24:29 +02:00
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# Kernel support
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2021-11-23 16:02:29 +01:00
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Currently, only context switch events are supported. The kernel events are
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usually written by the kernel into a buffer, without any action from user space.
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This behavior poses a problem, as the user space events and kernel events can
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leave a unsorted trace.
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The current workaround involves surounding the kernel events by two special ovni
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2022-08-29 16:24:29 +02:00
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event markers `OU[` and `OU]` which determine the region of events which must be
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2021-11-23 16:02:29 +01:00
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sorted first. Notice that the events inside the region must be sorted!
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The `ovnisort` tool has been designed to sort the events enclosed by those
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markers by using a very simple window sorting algorithm, trying to insert them
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in order by looking only at the past 10000 events.
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To use the kernel events, you must sort the ovni trace before calling the
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emulator:
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% ./application
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% ovnisort ovni
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% ovniemu ovni
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