Add Remaining and Size to perf/ring Record #1167
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perf/reader.go
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| Remaining int | ||
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| // The total size of the per-CPU perf buffer in bytes. | ||
| Size int |
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Size is fixed for the reader, why not expose this as Reader.Size() int instead? You can move the call to perfBufferSize from newPerfEventRing to NewReaderWithOptions. Same idea applies to ringbuf.Reader.
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The size we are interested in, is the data portion, without the metadata page. Moving the call to perfBufferSize would've required changes to a bunch of other places that expect newPerfEventRing to handle the size manipulation. I did something different, let me know what you think.
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Added. For the backward/overwriteable buffer it isn't possible to get a precise remaining count once it has been overwritten. |
We could. It does work correctly until any kind of overwrite happens, and then it becomes inaccurate by reporting more data remaining than their actually is (because of the partial leftover records). |
Signed-off-by: Bryce Kahle <bryce.kahle@datadoghq.com> Signed-off-by: Lorenz Bauer <lmb@isovalent.com>
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squashed |
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@lmb ready to go. |
This allows tracking utilization of the underlying buffers. Processing the values to make sense in a user's monitoring system is left to the user.
Using the post-read remaining bytes allows the value to reach zero, whereas a pre-read value would never reach zero.