Re: [Emacs-diffs] master 5018b66 4/6: Inhibit GC after inhibit_garbage_collection

[Paul Eggert <eggert@cs.ucla.edu>]

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Stefan Monnier wrote:
> Maybe we could circumvent this by temporarily bumping gc_relative_threshold?

Sure, I installed the attached. It bumps consing_until_gc which is how the 
thresholding works now.

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From d02c2f7f6507105605ed0596a7e26acd5b3b8122 Mon Sep 17 00:00:00 2001
From: Paul Eggert <eggert@cs.ucla.edu>
Date: Sun, 21 Jul 2019 11:20:07 -0700
Subject: [PATCH] Speed up maybe_gc when GC is inhibited

* src/alloc.c (allow_garbage_collection)
(inhibit_garbage_collection): Temporarily bump
consing_until_gc, to improve performance of maybe_gc while
garbage collection is inhibited.  Suggested by Stefan Monnier in:
https://lists.gnu.org/r/emacs-devel/2019-07/msg00511.html
---
 src/alloc.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/src/alloc.c b/src/alloc.c
index b7ba886482..50015808e5 100644
--- a/src/alloc.c
+++ b/src/alloc.c
@@ -5501,11 +5501,14 @@ staticpro (Lisp_Object const *varaddress)
 			  Protection from GC
  ***********************************************************************/
 
-/* Temporarily prevent garbage collection.  */
+/* Temporarily prevent garbage collection.  Temporarily bump
+   consing_until_gc to speed up maybe_gc when GC is inhibited.  */
 
 static void
-allow_garbage_collection (void)
+allow_garbage_collection (void *ptr)
 {
+  object_ct *p = ptr;
+  consing_until_gc = *p;
   garbage_collection_inhibited--;
 }
 
@@ -5513,9 +5516,10 @@ ptrdiff_t
 inhibit_garbage_collection (void)
 {
   ptrdiff_t count = SPECPDL_INDEX ();
-
-  record_unwind_protect_void (allow_garbage_collection);
+  object_ct consing = consing_until_gc;
+  record_unwind_protect_ptr (allow_garbage_collection, &consing);
   garbage_collection_inhibited++;
+  consing_until_gc = OBJECT_CT_MAX;
   return count;
 }
 
-- 
2.17.1