Hi, On 2022-08-08 15:12:08 +0900, Kyotaro Horiguchi wrote: > At Sat, 6 Aug 2022 19:19:39 -0700, Andres Freund <and...@anarazel.de> wrote in > > Hi, > > > > On 2022-08-05 17:22:38 +0900, Kyotaro Horiguchi wrote: > > > I think it a bit different. Previously that memory (but for a bit > > > different use, precisely) was required only when stats data is read so > > > almost all server processes didn't need it. Now, every server process > > > that uses pgstats requires the two memory if it is going to write > > > stats. Even if that didn't happen until process termination, that > > > memory eventually required to flush possibly remaining data. That > > > final write might be avoidable but I'm not sure it's worth the > > > trouble. As the result, calling pgstat_initialize() is effectively > > > the declaration that the process requires the memory. > > > > I don't think every process will end up calling pgstat_setup_memcxt() - > > e.g. walsender, bgwriter, checkpointer probably don't? What do we gain by > > creating the contexts eagerly? > > Yes. they acutally does, in shmem_shutdown hook function, during > at-termination stats write. I didn't consider to make that not > happen, to save 2kB of memory on such small number of processes.
That's true for checkpointer, but not e.g. for walwriter, bgwriter. I don't see why we should force allocate memory that we're never going to use in background processes. > And we don't hastle to avoid maybe-empty at-process-termination > writes.. Hm? Greetings, Andres Freund
