Re: Fix pg_log_backend_memory_contexts() 's delay

Thanks for your review.

>> Thanks for the patch. Do we also need to do the change in
>> HandleMainLoopInterrupts, HandleCheckpointerInterrupts,
>> HandlePgArchInterrupts, HandleWalWriterInterrupts as we don't call
>> CHECK_FOR_INTERRUPTS() there?

> Yeah, that's still some information that the user asked for.  Looking
> at the things that have a PGPROC entry, should we worry about the main
> loop of the logical replication launcher?

・Now, the target of “pg_log_backend_memory_contexts()” is “autovacuum 
launcher” and “logical replication launcher”.  I observed that the delay 
occurred only in “autovacuum launcher” not in “logical replication 
launcher”.
・”autovacuum launcher” used “HandleAutoVacLauncherInterrupts()” ( not 
including “ProcessLogMemoryContextInterrupt()” ) instead of 
“ProcessInterrupts() ( including “ProcessLogMemoryContextInterrupt()” ). 
“ProcessLogMemoryContextInterrupt()” will not be executed until the next 
“ProcessInterrupts()” is executed. So, I added 
“ProcessLogMemoryContextInterrupt()”.
・”logical replication launcher” uses only “ProcessInterrupts()”. So, We 
don’t have to fix it.

> IMHO, we can support all the processes which return a PGPROC entry by
> both BackendPidGetProc and AuxiliaryPidGetProc where the
> AuxiliaryPidGetProc would cover the following processes. I'm not sure
> one is interested in the  memory context info of auxiliary processes.

・The purpose of this patch is to solve the delay problem, so I would 
like another patch to deal with “ BackendPidGetProc” and 
“AuxiliaryPidGetProc”.

Regards,
Koyu Tanigawa