andreacavalli/rocksdb
0
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

Relax memory order for faster tickers

Browse Source 
Summary:
The default behavior for atomic operations is sequentially consistent ordering
which is not needed for simple counters (see:
http://en.cppreference.com/w/cpp/atomic/memory_order). Change the memory order
to std::memory_order_relaxed for better performance.

Test Plan: make clean all check

Reviewers: rven, anthony, yhchiang, aekmekji, sdong, MarkCallaghan, igor

Reviewed By: igor

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D46953
This commit is contained in:
Andres Noetzli 2015-09-15 10:52:00 -07:00
parent 4886073174
commit df22e2fb71
1 changed files with 2 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
util/statistics.cc
View File

@ -62,7 +62,7 @@ void StatisticsImpl::setTickerCount(uint32_t tickerType, uint64_t count) {
tickerType < INTERNAL_TICKER_ENUM_MAX : tickerType < INTERNAL_TICKER_ENUM_MAX :
tickerType < TICKER_ENUM_MAX); tickerType < TICKER_ENUM_MAX);
if (tickerType < TICKER_ENUM_MAX || enable_internal_stats_) { if (tickerType < TICKER_ENUM_MAX || enable_internal_stats_) {
tickers_[tickerType].value = count; tickers_[tickerType].value.store(count, std::memory_order_relaxed);
} }
if (stats_ && tickerType < TICKER_ENUM_MAX) { if (stats_ && tickerType < TICKER_ENUM_MAX) {
stats_->setTickerCount(tickerType, count); stats_->setTickerCount(tickerType, count);
@ -75,7 +75,7 @@ void StatisticsImpl::recordTick(uint32_t tickerType, uint64_t count) {
tickerType < INTERNAL_TICKER_ENUM_MAX : tickerType < INTERNAL_TICKER_ENUM_MAX :
tickerType < TICKER_ENUM_MAX); tickerType < TICKER_ENUM_MAX);
if (tickerType < TICKER_ENUM_MAX || enable_internal_stats_) { if (tickerType < TICKER_ENUM_MAX || enable_internal_stats_) {
tickers_[tickerType].value += count; tickers_[tickerType].value.fetch_add(count, std::memory_order_relaxed);
} }
if (stats_ && tickerType < TICKER_ENUM_MAX) { if (stats_ && tickerType < TICKER_ENUM_MAX) {
stats_->recordTick(tickerType, count); stats_->recordTick(tickerType, count);