Re: Generate wait event list and docs from text file

On Mon, Aug 14, 2017 at 11:58 PM, Michael Paquier
<michael(dot)paquier(at)gmail(dot)com> wrote:
> 1) It is easy to add a wait event and...
> 2) It is easy to not update its documentation.
> 3) the documentation tables get easily broken.
>
> As I have participated in the situation present now, I propose to
> write a patch to make the maintenance of the whole thing easier,
> because wait events are important, and because I see more of them
> added in the future.

Seems an apt occasion to point out that 10rc1 is missing documentation
for a couple events.

From src/backend/storage/lmgr/lwlocknames.txt: CLogTruncationLock was
added to the
docs but BackendRandomLock and LogicalRepWorkerLock are missing. (Maybe there's
a reason for this... I just checked the diffs from 9.6 to 10 then
checked the docs for
completeness.)

> Using this set of meta-data, it is possible to generate the SGMO
> tables and the set of include tables.

The lock-related events might present a challenge here since they come
from a different
place. In particular, there is no single location to find the
descriptions of tranche locks - you
have to search through the source code and find the
LWLockRegisterTranche() call to see
what text it used for the lock name! (Consolidating that seems like a
great candidate for a
patch...)

-Jeremy

P.S. The number of wait events has gone from 69 in 9.6 up to 184 in 10rc1. IMHO
this is very much worth mentioning as a new feature for postgresql 10!
I counted
67 new I/O related events, 31 new latch-related events and 8 new
replication-related
events! Seems like a big deal to me. :)

--
http://about.me/jeremy_schneider