rocksdb/db
Nathan Bronson 1ae27113c7 reduce comparisons by skiplist
Summary:
Key comparison is the single largest CPU user for CPU-bound
workloads. This diff reduces the number of comparisons in two ways.

The first is that it moves predecessor array gathering from
FindGreaterOrEqual to FindLessThan, so that FindGreaterOrEqual can
return immediately if compare_ returns 0.  As part of this change I
moved the sequential insertion optimization into Insert, to remove the
undocumented (and smelly) requirement that prev must be equal to prev_
if it is non-null.

The second optimization is that all of the search functions skip calling
compare_ when moving to a lower level that has the same Next pointer.
With a branching factor of 4 we would expect this to happen 1/4 of
the time.

On a single-threaded CPU-bound workload (-benchmarks=fillrandom -threads=1
-batch_size=1 -memtablerep=skip_list -value_size=0 --num=1600000
-level0_slowdown_writes_trigger=9999 -level0_stop_writes_trigger=9999
-disable_auto_compactions --max_write_buffer_number=8
-max_background_flushes=8 --disable_wal --write_buffer_size=160000000)
on my dev server this is good for a 7% perf win.

Test Plan: unit tests

Reviewers: rven, ljin, yhchiang, sdong, igor

Reviewed By: igor

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D43233
2015-08-11 11:25:22 -07:00
..
builder.cc Move rate_limiter, write buffering, most perf context instrumentation and most random kill out of Env 2015-07-17 16:58:18 -07:00
builder.h Move rate_limiter, write buffering, most perf context instrumentation and most random kill out of Env 2015-07-17 16:58:18 -07:00
c_test.c Deprecate CompactionFilterV2 2015-07-17 18:59:11 +02:00
c.cc Don't let flushes preempt compactions 2015-07-17 12:02:52 -07:00
column_family_test.cc Removing duplicate code 2015-08-05 07:33:27 -07:00
column_family.cc Don't let flushes preempt compactions 2015-07-17 12:02:52 -07:00
column_family.h Fail DB::Open() when the requested compression is not available 2015-06-18 14:55:05 -07:00
compact_files_test.cc Improved FileExists API 2015-07-20 17:20:40 -07:00
compacted_db_impl.cc Remove db_impl_readonly dependency on utilities 2015-07-14 11:32:54 -07:00
compacted_db_impl.h Remove db_impl_readonly dependency on utilities 2015-07-14 11:32:54 -07:00
compaction_job_stats_test.cc Update Tests To Enable Subcompactions 2015-08-04 22:19:07 -07:00
compaction_job_test.cc Fix clang build 2015-08-10 11:30:36 -07:00
compaction_job.cc Better CompactionJob testing 2015-08-07 21:59:51 -07:00
compaction_job.h Parallelize L0-L1 Compaction: Restructure Compaction Job 2015-08-03 11:32:14 -07:00
compaction_picker_test.cc Make compaction_picker_test runnable in ROCKSDB_LITE 2015-07-20 10:46:09 -07:00
compaction_picker.cc Fix CompactFiles by adding all necessary files 2015-08-03 15:53:22 -07:00
compaction_picker.h Fix when output level is 0 of universal compaction with trivial move 2015-07-27 14:25:57 -07:00
compaction.cc Fix when output level is 0 of universal compaction with trivial move 2015-07-27 14:25:57 -07:00
compaction.h Parallelize L0-L1 Compaction: Restructure Compaction Job 2015-08-03 11:32:14 -07:00
comparator_db_test.cc Make "make all" work for CYGWIN 2015-06-09 16:36:07 -07:00
convenience.cc move convenience.h out of utilities 2015-07-15 14:51:51 -07:00
corruption_test.cc Don't let flushes preempt compactions 2015-07-17 12:02:52 -07:00
cuckoo_table_db_test.cc Block cuckoo table tests in ROCKSDB_LITE 2015-07-20 10:50:46 -07:00
db_bench.cc db_bench add an option of --universal_allow_trivial_move 2015-07-20 11:56:12 -07:00
db_compaction_filter_test.cc Don't let flushes preempt compactions 2015-07-17 12:02:52 -07:00
db_compaction_test.cc Update Tests To Enable Subcompactions 2015-08-04 22:19:07 -07:00
db_dynamic_level_test.cc Move DynamicLevel related db-tests to db_dynamic_level_test.cc 2015-07-13 19:00:30 -07:00
db_filesnapshot.cc Add wal files to Checkpoint for multiple column families. 2015-06-19 16:08:31 -07:00
db_impl_debug.cc Deprecate WriteOptions::timeout_hint_us 2015-07-14 09:35:48 +02:00
db_impl_experimental.cc Clean up InstallSuperVersion 2015-06-17 12:37:59 -07:00
db_impl_readonly.cc Remove db_impl_readonly dependency on utilities 2015-07-14 11:32:54 -07:00
db_impl_readonly.h Use CompactRangeOptions for CompactRange 2015-06-17 14:36:14 -07:00
db_impl.cc Avoid type unique_ptr in LogWriterNumber::writer for Windows build break 2015-08-06 10:52:41 -07:00
db_impl.h simple ManagedSnapshot wrapper 2015-08-06 17:59:05 -07:00
db_inplace_update_test.cc Move in-place-update related tests from db_test.cc to db_inplace_update_test.cc 2015-07-20 16:05:28 -07:00
db_iter_test.cc Fixing endless loop if seeking to end of key with seq num 0 2015-08-06 10:43:28 -07:00
db_iter.cc Fixing endless loop if seeking to end of key with seq num 0 2015-08-06 10:43:28 -07:00
db_iter.h reduce references to cfd->options() in DBImpl 2014-09-08 15:04:34 -07:00
db_log_iter_test.cc Make TransactionLogIterator related tests from db_test.cc to db_log_iter_test.cc 2015-07-14 16:08:21 -07:00
db_tailing_iter_test.cc Move TailingIterator tests from db_test.cc to db_test_tailing_iterator.cc 2015-07-14 16:41:08 -07:00
db_test.cc simple ManagedSnapshot wrapper 2015-08-06 17:59:05 -07:00
db_universal_compaction_test.cc Fix when output level is 0 of universal compaction with trivial move 2015-07-27 14:25:57 -07:00
db_wal_test.cc Add two unit tests for SyncWAL() 2015-08-05 14:27:02 -07:00
dbformat_test.cc Avoid manipulating const char* arrays 2015-07-14 00:21:41 -07:00
dbformat.cc Replace %llu with format macros in ParsedInternalKey::DebugString()) 2015-06-17 20:44:26 -07:00
dbformat.h Avoid manipulating const char* arrays 2015-07-14 00:21:41 -07:00
deletefile_test.cc Improved FileExists API 2015-07-20 17:20:40 -07:00
event_helpers.cc Add EventListener::OnTableFileDeletion() 2015-06-03 19:57:01 -07:00
event_helpers.h Add EventListener::OnTableFileDeletion() 2015-06-03 19:57:01 -07:00
experimental.cc Implement DB::PromoteL0 method 2015-04-23 12:10:36 -07:00
fault_injection_test.cc [wal changes 3/3] method in DB to sync WAL without blocking writers 2015-08-05 06:06:39 -07:00
file_indexer_test.cc Fix possible SIGSEGV in CompactRange (github issue #596) 2015-04-29 10:52:31 -07:00
file_indexer.cc Fix possible SIGSEGV in CompactRange (github issue #596) 2015-04-29 10:52:31 -07:00
file_indexer.h Fix public API dependency on internal codes and dependency on MAX_INT32 2015-07-11 10:32:11 -07:00
filename_test.cc rocksdb: switch to gtest 2015-03-17 14:08:00 -07:00
filename.cc Move rate_limiter, write buffering, most perf context instrumentation and most random kill out of Env 2015-07-17 16:58:18 -07:00
filename.h Move rate_limiter, write buffering, most perf context instrumentation and most random kill out of Env 2015-07-17 16:58:18 -07:00
flush_job_test.cc Better CompactionJob testing 2015-08-07 21:59:51 -07:00
flush_job.cc Don't let flushes preempt compactions 2015-07-17 12:02:52 -07:00
flush_job.h simple ManagedSnapshot wrapper 2015-08-06 17:59:05 -07:00
flush_scheduler.cc Don't return (or dereference) dangling pointer 2014-10-02 14:33:16 -07:00
flush_scheduler.h Fix data race #1 2015-01-26 11:48:07 -08:00
forward_iterator.cc fixed leaking log::Writers 2015-07-07 12:10:10 -07:00
forward_iterator.h rocksdb: Add missing override 2015-02-26 11:28:41 -08:00
internal_stats.cc Report live data size estimate 2015-07-21 21:33:20 -07:00
internal_stats.h Report live data size estimate 2015-07-21 21:33:20 -07:00
job_context.h fixed leaking log::Writers 2015-07-07 12:10:10 -07:00
listener_test.cc Deprecate WriteOptions::timeout_hint_us 2015-07-14 09:35:48 +02:00
log_format.h Some minor refactoring on the code 2014-01-02 16:32:31 -08:00
log_reader.cc Move rate_limiter, write buffering, most perf context instrumentation and most random kill out of Env 2015-07-17 16:58:18 -07:00
log_reader.h Move rate_limiter, write buffering, most perf context instrumentation and most random kill out of Env 2015-07-17 16:58:18 -07:00
log_test.cc Removing duplicate code 2015-08-05 07:33:27 -07:00
log_writer.cc Move rate_limiter, write buffering, most perf context instrumentation and most random kill out of Env 2015-07-17 16:58:18 -07:00
log_writer.h Move rate_limiter, write buffering, most perf context instrumentation and most random kill out of Env 2015-07-17 16:58:18 -07:00
managed_iterator.cc Windows Port from Microsoft 2015-07-01 16:13:56 -07:00
managed_iterator.h Fixed xfunc related compile errors in ROCKSDB_LITE 2015-04-09 21:05:18 -07:00
memtable_allocator.cc Enforce write buffer memory limit across column families 2014-12-02 12:09:20 -08:00
memtable_allocator.h Enforce write buffer memory limit across column families 2014-12-02 12:09:20 -08:00
memtable_list_test.cc Removing duplicate code 2015-08-05 07:33:27 -07:00
memtable_list.cc Allow GetApproximateSize() to include mem table size if it is skip list memtable 2015-06-16 18:13:23 -07:00
memtable_list.h Allow GetApproximateSize() to include mem table size if it is skip list memtable 2015-06-16 18:13:23 -07:00
memtable.cc Allow GetApproximateSize() to include mem table size if it is skip list memtable 2015-06-16 18:13:23 -07:00
memtable.h Allow GetApproximateSize() to include mem table size if it is skip list memtable 2015-06-16 18:13:23 -07:00
memtablerep_bench.cc Windows Port from Microsoft 2015-07-01 16:13:56 -07:00
merge_context.h API to fetch from both a WriteBatchWithIndex and the db 2015-05-11 14:51:51 -07:00
merge_helper_test.cc Further cleanup of CompactionJob and MergeHelper 2015-07-28 19:21:55 -07:00
merge_helper.cc Further cleanup of CompactionJob and MergeHelper 2015-07-28 19:21:55 -07:00
merge_helper.h Further cleanup of CompactionJob and MergeHelper 2015-07-28 19:21:55 -07:00
merge_operator.cc Call merge operators with empty values 2015-06-26 11:35:46 -07:00
merge_test.cc Make merge_test runnable in ROCKSDB_LITE 2015-07-20 11:17:52 -07:00
perf_context_test.cc Makefile minor cleanup 2015-03-30 16:05:35 -04:00
plain_table_db_test.cc Block plain_table_db_test in ROCKSDB_LITE 2015-07-20 11:12:02 -07:00
prefix_test.cc Skip unsupported tests in ROCKSDB_LITE 2015-07-20 11:24:54 -07:00
repair.cc Move rate_limiter, write buffering, most perf context instrumentation and most random kill out of Env 2015-07-17 16:58:18 -07:00
skiplist_test.cc rocksdb: switch to gtest 2015-03-17 14:08:00 -07:00
skiplist.h reduce comparisons by skiplist 2015-08-11 11:25:22 -07:00
slice.cc Create an abstract interface for write batches 2015-03-17 19:23:08 -07:00
snapshot_impl.cc simple ManagedSnapshot wrapper 2015-08-06 17:59:05 -07:00
snapshot_impl.h simple ManagedSnapshot wrapper 2015-08-06 17:59:05 -07:00
table_cache.cc Add statistic histogram "rocksdb.sst.read.micros" 2015-08-05 13:02:33 -07:00
table_cache.h Add statistic histogram "rocksdb.sst.read.micros" 2015-08-05 13:02:33 -07:00
table_properties_collector_test.cc Removing duplicate code 2015-08-05 07:33:27 -07:00
table_properties_collector.cc A new call back to TablePropertiesCollector to allow users know the entry is add, delete or merge 2015-04-06 10:27:21 -07:00
table_properties_collector.h Add TablePropertiesCollector::NeedCompact() to suggest DB to further compact output files 2015-06-05 20:18:21 -07:00
transaction_log_impl.cc Move rate_limiter, write buffering, most perf context instrumentation and most random kill out of Env 2015-07-17 16:58:18 -07:00
transaction_log_impl.h Move rate_limiter, write buffering, most perf context instrumentation and most random kill out of Env 2015-07-17 16:58:18 -07:00
version_builder_test.cc Add TablePropertiesCollector::NeedCompact() to suggest DB to further compact output files 2015-06-05 20:18:21 -07:00
version_builder.cc Fix deleting obsolete files 2015-02-06 08:44:30 -08:00
version_builder.h Move VersionBuilder logic to a separate .cc file 2014-10-31 16:34:38 -07:00
version_edit_test.cc Add TablePropertiesCollector::NeedCompact() to suggest DB to further compact output files 2015-06-05 20:18:21 -07:00
version_edit.cc Added JSON manifest dump option to ldb command 2015-07-17 10:07:40 -07:00
version_edit.h Added JSON manifest dump option to ldb command 2015-07-17 10:07:40 -07:00
version_set_test.cc Report live data size estimate 2015-07-21 21:33:20 -07:00
version_set.cc Better CompactionJob testing 2015-08-07 21:59:51 -07:00
version_set.h Add DBOptions::skip_sats_update_on_db_open 2015-08-04 13:48:16 -07:00
wal_manager_test.cc Skip unsupported tests in ROCKSDB_LITE 2015-07-20 11:24:54 -07:00
wal_manager.cc Improved FileExists API 2015-07-20 17:20:40 -07:00
wal_manager.h Fix -Wnon-virtual-dtor errors 2014-11-10 17:39:38 -05:00
write_batch_base.cc WriteBatch.Merge w/ SliceParts support 2015-05-29 04:30:03 -07:00
write_batch_internal.h WriteBatch Save Points 2015-07-29 16:54:23 -07:00
write_batch_test.cc WriteBatch Save Points 2015-07-29 16:54:23 -07:00
write_batch.cc simple ManagedSnapshot wrapper 2015-08-06 17:59:05 -07:00
write_callback_test.cc Fix compile for write_callback_test in ROCKSDB_LITE 2015-07-20 10:54:15 -07:00
write_callback.h Optimistic Transactions 2015-05-29 14:36:35 -07:00
write_controller_test.cc Slow down writes by bytes written 2015-06-11 20:42:18 -07:00
write_controller.cc Slow down writes by bytes written 2015-06-11 20:42:18 -07:00
write_controller.h Slow down writes by bytes written 2015-06-11 20:42:18 -07:00
write_thread.cc Deprecate WriteOptions::timeout_hint_us 2015-07-14 09:35:48 +02:00
write_thread.h Deprecate WriteOptions::timeout_hint_us 2015-07-14 09:35:48 +02:00
writebuffer.h Enforce write buffer memory limit across column families 2014-12-02 12:09:20 -08:00