On Mon, May 08, 2023 at 05:57:09PM +0530, Bharath Rupireddy wrote: > I ran performance tests on the patch with different use-cases. Clearly > the patch reduces burden on LWLock's waitlist lock (evident from perf > reports [1]). However, to see visible impact in the output, the txns > must be generating small (between 16 bytes to 2 KB) amounts of WAL in > a highly concurrent manner, check the results below (FWIW, I've zipped > and attached perf images for better illustration along with test > setup). > > When the txns are generating a small amount of WAL i.e. between 16 > bytes to 2 KB in a highly concurrent manner, the benefit is clearly > visible in the TPS more than 2.3X improvement. When the txns are > generating more WAL i.e. more than 2 KB, the gain from reduced burden > on waitlist lock is offset by increase in the wait/release for WAL > insertion locks and no visible benefit is seen. > > As the amount of WAL each txn generates increases, it looks like the > benefit gained from reduced burden on waitlist lock is offset by > increase in the wait for WAL insertion locks.
Nice. > test-case 1: -T5, WAL ~16 bytes > test-case 1: -t1000, WAL ~16 bytes I wonder if it's worth doing a couple of long-running tests, too. -- Nathan Bossart Amazon Web Services: https://aws.amazon.com
