For the synchronous backends efficiently preserve the order for
completion requests through the use of VecDequeue. Preserving the order
is not required but is beneficial as it matches the existing
optimisation that looks to match completions and requests.
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
Rather than aggregate the completion list into an intermediate vector
instead adjust the API to provide one completion item at a time.
With DHAT this shows the number of heap allocations has decreased.
Before:
dhat: Total: 623,852 bytes in 8,157 blocks
After:
dhat: Total: 380,444 bytes in 3,469 blocks
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
Rather than passing the vector of iovecs for the I/O to act on pass a
reference to the slice of values inside them. This removes the explicit
container type from the API allowing the use of e.g. SmallVec.
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
Using directly preadv and pwritev, we can simply use a RawFd instead of
a file, and we don't need to use the more complex implementation from
the qcow crate.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Since QCOW and RAW synchronous implementation are very close, it makes
sense to introduce some common functions that can be shared between
these two.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Based on the synchronous RAW file implementation present in the qcow
crate, we created a new raw_sync module in block_util that ports this
synchronous implementation to the AsyncIo trait.
The point is to reuse virtio-blk asynchronous implementation for both
synchronous and asynchronous backends.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
