Re: exposing wait events for non-backends (was: Tracking wait event for latches)

Hi Kuntal,

Patches apply and compile fine. Works as advertised.

Some minor comments on the patches themselves.

In 0001:

- * pgstat_bestart() -
+ * pgstat_procstart() -
+ *
+ * Initialize this process's entry in the PgBackendStatus array.
+ * Called from InitPostgres and AuxiliaryProcessMain.

Not being called from AuxiliaryProcessMain(). Maybe leftover comment from
a previous version. Actually I see that in patch 0002, Main() functions
of various auxiliary processes call pgstat_procstart, not
AuxiliaryProcessMain.

+ * user-defined functions which expects ids of backends starting from
1 to

s/expects/expect/g

+/*
+ * AuxiliaryPidGetProc -- get PGPROC for an auxiliary process
+ * given its PID
+ *
+ * Returns NULL if not found.
+ */
+PGPROC *
+AuxiliaryPidGetProc(int pid)
+{
+ PGPROC *result;

Initialize to NULL so that the comment above is true. :)

In 0002:

@@ -248,6 +248,9 @@ BackgroundWriterMain(void)
*/
prev_hibernate = false;

+ /* report walwriter process in the PgBackendStatus array */
+ pgstat_procstart();
+

s/walwriter/writer/g

Patch 0004 should update monitoring.sgml.

Thanks,
Amit