rocksdb/util/perf_level_imp.h

//  Copyright (c) 2013, Facebook, Inc.  All rights reserved.
//  This source code is licensed under the BSD-style license found in the
//  LICENSE file in the root directory of this source tree. An additional grant
//  of patent rights can be found in the PATENTS file in the same directory.
//
#pragma once
#include "rocksdb/perf_level.h"

namespace rocksdb {

#if defined(IOS_CROSS_COMPILE)
extern PerfLevel perf_level;
#else
extern __thread PerfLevel perf_level;
#endif

}  // namespace rocksdb
more times in perf_context and iostats_context Summary: We occasionally get write stalls (>1s Write() calls) on HDD under read load. The following timers explain almost all of the stalls: - perf_context.db_mutex_lock_nanos - perf_context.db_condition_wait_nanos - iostats_context.open_time - iostats_context.allocate_time - iostats_context.write_time - iostats_context.range_sync_time - iostats_context.logger_time In my experiments each of these occasionally takes >1s on write path under some workload. There are rare cases when Write() takes long but none of these takes long. Test Plan: Added code to our application to write the listed timings to log for slow writes. They usually add up to almost exactly the time Write() call took. Reviewers: rven, yhchiang, sdong Reviewed By: sdong Subscribers: march, dhruba, tnovak Differential Revision: https://reviews.facebook.net/D39177 10 years ago			`// Copyright (c) 2013, Facebook, Inc. All rights reserved.`
			`// This source code is licensed under the BSD-style license found in the`
			`// LICENSE file in the root directory of this source tree. An additional grant`
			`// of patent rights can be found in the PATENTS file in the same directory.`
			`//`
			`#pragma once`
			`#include "rocksdb/perf_level.h"`

			`namespace rocksdb {`

			`#if defined(IOS_CROSS_COMPILE)`
			`extern PerfLevel perf_level;`
			`#else`
			`extern __thread PerfLevel perf_level;`
			`#endif`

			`} // namespace rocksdb`