The underlying chunks returned from PullUp should not be shared,
since the underlying slice can sometimes be directly modified. This change
also reworks some of the network parsing code so that ownership of
views is more explicit to the reader.
PiperOrigin-RevId: 538230394
Merge clears the other buffer, so rather than cloning and dealing with
refcounts, we can just steal other's view list and adjust sizes.
This increases the speed of Merge 10x, and this was with a benchmark that
didn't do any TrimFront/Truncate (which will induce copying in the old
implementation).
BenchmarkMerge
BenchmarkMerge-33 99412884 12.74 ns/op 0 B/op 0 allocs/op
BenchmarkOldMerge
BenchmarkOldMerge-33 6075222 217.4 ns/op 0 B/op 0 allocs/op
This change uncovered that PacketBuffer.DeepCopyForForwarding wasn't doing a
true deep copy. It seems that, in the ICMP error path, a call to Merge was
forcing a deep copy (maybe because Append was copying bytes), obfuscating the
issue. This change also addresses that issue by having DeepCopyForForwarding
produce a copy that shares no data with other packets.
PiperOrigin-RevId: 537143838
Benchmark iperf3:
Before After
native->runsc 5.14 5.01 (Gbps)
runsc->native 4.15 4.07 (Gbps)
It did introduce overhead, mainly at the bridge between pkg/buffer and
VectorisedView, the ExtractVV method. Once endpoints start migrating away from
VV, this overhead will be gone.
Updates #2404
PiperOrigin-RevId: 373651666
This change changes `buffer.data` into a `[]byte`, from `[bufferSize]byte`.
In exchange, each `buffer` is now grouped together to reduce the number of
allocation. Plus, `View` now holds an embeded list of `buffer` (via `pool`) to
support the happy path which the number of buffer is small. Expect no extra
allocation for the happy path.
It is to enable the use case for PacketBuffer, which
* each `View` is small (way less than `defaultBufferSize`), and
* needs to dynamically transfer ownership of `[]byte` to `View`.
(to allow gradual migration)
PiperOrigin-RevId: 333197252
Lucas Manning
Kevin Krakauer
Ting-Yu Wang
Adin Scannell