Re: [RFC PATCH 1/3] Unified trace buffer

[Martin Bligh]

> I rather like this idea, as it gives small entries (the common case) the
> least overhead but does allow for larger ones.
>
> By also putting the time in there you can do the merge sort iterator,
> Linus was right that everybody wants this anyway.
>
> As for delta encoding the time, we could make the tick log the absolute
> time packet, that's at least 100Hz and it already has to compute the
> full gtod thing anyway.
>
> I don't much like Linus' idea of bringing type information back into the
> primitive header (sorry Linus ;-)). I'd much rather keep that
> abstraction in the next layer.

There is part of the type stuff that belongs in the lower layer, it seems -
the padding events for the up-to-end-of-page buffering, and the timestamp
extensions. It seems wrong to split those across two layers.

But perhaps we can keep a couple of bits for this, and three of the bits
to represent the length of the data payload (maybe in 4 byte multiples
rather than bytes?) That'd let up to 28 bytes as a payload in a short event.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/