Merged patch series from Avi Kivity:
The static row can be rare: many tables don't have them, and tables
that do will often have mutations without them (if the static row
is rarely updated, it may be present in the cache and in readers,
but absent in memtable mutations). However, it always consumes ~100
bytes of memory, even if it not present, due to row's overhead.
Change it to be optional by allocating it as an external object rather
than inlined into mutation_partition. This adds overhead when the
static row is present (17 bytes for the reference, back reference,
and lsa allocator overhead).
perf_simple_query appears to marginally (2%) faster. Footprint is
reduced by ~9% for a cache entry, 12% in memtables. More details are
provided in the patch commitlog.
Tests: unit (debug)
Avi Kivity (4):
managed_ref: add get() accessor
managed_ref: add external_memory_usage()
mutation_partition: introduce lazy_row
mutation_partition: make static_row optional to reduce memory
footprint
cell_locking.hh | 2 +-
converting_mutation_partition_applier.hh | 4 +-
mutation_partition.hh | 284 ++++++++++++++++++++++-
partition_builder.hh | 4 +-
utils/managed_ref.hh | 12 +
flat_mutation_reader.cc | 2 +-
memtable.cc | 2 +-
mutation_partition.cc | 45 +++-
mutation_partition_serializer.cc | 2 +-
partition_version.cc | 4 +-
tests/multishard_mutation_query_test.cc | 2 +-
tests/mutation_source_test.cc | 2 +-
tests/mutation_test.cc | 12 +-
tests/sstable_mutation_test.cc | 10 +-
14 files changed, 355 insertions(+), 32 deletions(-)
51fc6c7a8e