Hi, On 2026-10-14 21:53:21 +0100, Alexandre Felipe wrote: > See attached, running on top of 10cc5aa96a6 I got > > clients base patched > > 1 3251.2 3221.3 > 8 2592.2 3979.0 *+53.5%*
Given how low the throughput is, you must be testing read/write pgbench. Is that right? If so, it's completely inconceivable that that lwock efficiency has that kind of impact at such low throughput & concurrency. You're waiting for the disk, not a CAS retry. It'd be more likely that what you're measuring WAL file initialization overhead or such. There's no way that you'd ever see any meaningful benefits of something like this until you reach much much higher concurrency. The timeframe between reading the "old" value and the CAS is very short, it's pretty hard to steal the cacheline in that window and modify it. Greetings, Andres Freund
