On Wed, Oct 13, 2021 at 4:25 AM Andres Freund <and...@anarazel.de> wrote: > > Hi, > > On 2021-10-11 15:24:46 +0900, Fujii Masao wrote: > > How about modifying SharedInvalBackendInit() so that it accepts > > BackendId as an argument and allocates the ProcState entry of > > the specified BackendId? That is, the startup process determines > > that its BackendId is "MaxBackends + MyAuxProcType (=StartupProcess) + 1" > > in AuxiliaryProcessMain(), and then it passes that BackendId to > > SharedInvalBackendInit() in InitRecoveryTransactionEnvironment(). > > If I understand correctly what you're proposing, I think that's going in the > wrong direction. We should work towards getting rid of BackendIds > instead. This whole complication vanishes if we make sinvaladt use pgprocno. > > See https://postgr.es/m/20210802171255.k4yv5cfqaqbuuy6f%40alap3.anarazel.de > for some discussion of this.
Will any of the backends get pgprocno greater than MaxBackends? The pgprocno can range from 0 to ((MaxBackends + NUM_AUXILIARY_PROCS + max_prepared_xacts) - 1) and the ProcState array size is MaxBackends. How do we put a backend with pgprocno > MaxBackends, into the ProcState array? Is it that we also increase ProcState array size to (MaxBackends + NUM_AUXILIARY_PROCS + max_prepared_xacts)? Probably this is the dumbest thing as some slots are unused (NUM_AUXILIARY_PROCS - 1 + max_prepared_xacts slots. -1 because the startup process needs a ProcState slot) and the shared memory is wasted. Regards, Bharath Rupireddy.
