Re: Inlining of couple of functions in pl_exec.c improves performance

On Sun, 31 May 2020 at 08:04, Michael Paquier <michael@paquier.xyz> wrote:
> This stuff is interesting.  Do you have some perf profiles to share?
> I am wondering what's the effect of the inlining with your test
> cases.

Below are the perf numbers for asignmany.sql :

HEAD :

+   16.88%  postgres  postgres           [.] CachedPlanIsSimplyValid
+   16.64%  postgres  plpgsql.so         [.] exec_stmt
+   15.56%  postgres  plpgsql.so         [.] exec_eval_expr
+   13.58%  postgres  plpgsql.so         [.] exec_assign_value
+    7.49%  postgres  plpgsql.so         [.] exec_cast_value
+    7.17%  postgres  plpgsql.so         [.] exec_assign_expr
+    5.39%  postgres  postgres           [.] MemoryContextReset
+    3.91%  postgres  postgres           [.] ExecJustConst
+    3.33%  postgres  postgres           [.] recomputeNamespacePath
+    2.88%  postgres  postgres           [.] OverrideSearchPathMatchesCurrent
+    2.18%  postgres  plpgsql.so         [.] exec_eval_cleanup.isra.17
+    2.15%  postgres  plpgsql.so         [.] exec_stmts
+    1.32%  postgres  plpgsql.so         [.] MemoryContextReset@plt
+    0.57%  postgres  plpgsql.so         [.] CachedPlanIsSimplyValid@plt
+    0.57%  postgres  postgres           [.] GetUserId
     0.30%  postgres  plpgsql.so         [.] assign_simple_var.isra.13
     0.05%  postgres  [kernel.kallsyms]  [k] unmap_page_range

Patched :

+   18.22%  postgres  postgres           [.] CachedPlanIsSimplyValid
+   17.25%  postgres  plpgsql.so         [.] exec_eval_expr
+   16.31%  postgres  plpgsql.so         [.] exec_stmts
+   15.00%  postgres  plpgsql.so         [.] exec_assign_value
+    7.56%  postgres  plpgsql.so         [.] exec_assign_expr
+    5.64%  postgres  postgres           [.] MemoryContextReset
+    5.16%  postgres  postgres           [.] ExecJustConst
+    4.86%  postgres  postgres           [.] recomputeNamespacePath
+    4.54%  postgres  postgres           [.] OverrideSearchPathMatchesCurrent
+    2.33%  postgres  plpgsql.so         [.] exec_eval_cleanup.isra.17
+    1.26%  postgres  plpgsql.so         [.] MemoryContextReset@plt
+    0.81%  postgres  postgres           [.] GetUserId
+    0.71%  postgres  plpgsql.so         [.] CachedPlanIsSimplyValid@plt
     0.26%  postgres  plpgsql.so         [.] assign_simple_var.isra.13
     0.03%  postgres  [kernel.kallsyms]  [k] unmap_page_range
     0.02%  postgres  [kernel.kallsyms]  [k] mark_page_accessed

Notice the reduction in percentages :
HEAD : exec_stmts + exec_stmt = 18.79
Patched : exec_stmts = 16.31

HEAD : exec_assign_value + exec_cast_value : 21.07
Patched : exec_assign_value = 15.00

As expected, reduction of percentage in these two functions caused
other functions like CachedPlanIsSimplyValid() and exec_eval_expr() to
show rise in their percentages.