Answering my own question... I now see that the wakeup does in fact happen in StrategyGetBuffer(). Sorry for the noise.
On 6/16/22, 5:32 PM, "Jim Nasby" <nas...@amazon.com> wrote: While browsing through some of the clock-sweep code I noticed that the only place StrategyNotifyBgWriter() is called now is in BackgroundWriterMain()[1]. Presumably this isn't what's desired. If nothing else, it means the function's description comment is wrong, as are comments in BackgroundWriterMain(). This isn't new; 9.2 shows the same thing and that's when the function was added. I'm not sure what the right fix here is, since ISTM joggling bgwriter for every call to BufferAlloc() would be overkill. 1: https://doxygen.postgresql.org/freelist_8c.html#aabbd7d3891afc1d8531c3871d08d4b28