Summary:
This makes it easier to debug with tools like `ps`. The change only
applies to builds with glibc 2.30+ and _GNU_SOURCE extensions enabled.
We could adopt it in more cases by using the syscall but this is enough
for our build.
Replaces https://github.com/facebook/rocksdb/issues/2973.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9164
Test Plan:
- ran some benchmarks and correlated logged thread IDs with those shown by `ps -L`.
- verified no noticeable regression in throughput for log heavy (more than 700k log lines and over 5k / second) scenario.
Benchmark command:
```
$ TEST_TMPDIR=/dev/shm ./db_bench -benchmarks=filluniquerandom -compression_type=none -max_bytes_for_level_multiplier=2 -write_buffer_size=262144 -num_levels=7 -max_bytes_for_level_base=2097152 -target_file_size_base=524288 -level_compaction_dynamic_level_bytes=true -max_background_jobs=12 -num=20000000
```
Results before: 15.9MB/s, 15.8MB/s, 16.0MB/s
Results after: 16.3MB/s, 16.3MB/s, 15.8MB/s
- Rely on CI to test the fallback behavior
Reviewed By: riversand963
Differential Revision: D32399660
Pulled By: ajkr
fbshipit-source-id: c24d44fdf7782faa616ef0a0964eaca3539d9c24
9bb13c56b3