>>>>> "Richard" == Richard M Stallman <[EMAIL PROTECTED]> writes:
> I'd had already suggested a change to grow gc-cons-threshold as the heap
> grows (a long time ago), and I see that XEmacs's gc-cons-percentage is
> clean interface to such a feature. I think we should introduce this
> variable and give it a good non-zero default value.
> I agree. Would you like to do it?
How 'bout the patch below.
It sets the default value to 0.1 (i.e. 10%), which means that the current
400KB threshold (on 32 bit systems) is used until the heap grows to 4MB.
A 4MB heap is not enormous, but it's not small either (my one week old
running Emacs process with 14 frames and 30 buffers has a heap of about
6MB). This notion of "heap size" is not exactly what you'd expect (it
ignores buffers and a few other such things) but it reflects fairly well the
part of the heap that the GC actually cares about.
Stefan
--- orig/src/alloc.c
+++ mod/src/alloc.c
@@ -180,6 +180,8 @@
/* Number of bytes of consing since GC before another GC should be done. */
EMACS_INT gc_cons_threshold;
+static EMACS_INT gc_cons_min_threshold;
+static Lisp_Object Vgc_cons_percentage;
/* Nonzero during GC. */
@@ -4966,8 +4968,29 @@
gc_in_progress = 0;
consing_since_gc = 0;
- if (gc_cons_threshold < 10000)
- gc_cons_threshold = 10000;
+ if (gc_cons_min_threshold < 10000)
+ gc_cons_min_threshold = 10000;
+
+ gc_cons_threshold = gc_cons_min_threshold;
+
+ if (FLOATP (Vgc_cons_percentage))
+ { /* Set gc_cons_threshold. */
+ EMACS_INT total = 0;
+ EMACS_INT threshold;
+ total += total_conses * sizeof (struct Lisp_Cons);
+ total += total_symbols * sizeof (struct Lisp_Symbol);
+ total += total_markers * sizeof (union Lisp_Misc);
+ total += total_string_size;
+ total += total_vectors * sizeof (struct Lisp_Vector);
+ total += total_vector_size * sizeof (Lisp_Object);
+ total += total_floats * sizeof (struct Lisp_Float);
+ total += total_intervals * sizeof (struct interval);
+ total += total_strings * sizeof (struct Lisp_String);
+
+ threshold = total * XFLOAT_DATA (Vgc_cons_percentage);
+ if (threshold > gc_cons_threshold)
+ gc_cons_threshold = threshold;
+ }
if (garbage_collection_messages)
{
@@ -6087,7 +6110,7 @@
byte_stack_list = 0;
staticidx = 0;
consing_since_gc = 0;
- gc_cons_threshold = 100000 * sizeof (Lisp_Object);
+ gc_cons_min_threshold = 100000 * sizeof (Lisp_Object);
#ifdef VIRT_ADDR_VARIES
malloc_sbrk_unused = 1<<22; /* A large number */
malloc_sbrk_used = 100000; /* as reasonable as any number */
@@ -6124,7 +6147,7 @@
void
syms_of_alloc ()
{
- DEFVAR_INT ("gc-cons-threshold", &gc_cons_threshold,
+ DEFVAR_INT ("gc-cons-threshold", &gc_cons_min_threshold,
doc: /* *Number of bytes of consing between garbage collections.
Garbage collection can happen automatically once this many bytes have been
allocated since the last garbage collection. All data types count.
@@ -6132,7 +6155,15 @@
Garbage collection happens automatically only when `eval' is called.
By binding this temporarily to a large number, you can effectively
-prevent garbage collection during a part of the program. */);
+prevent garbage collection during a part of the program.
+See also `gc-cons-percentage'. */);
+
+ DEFVAR_LISP ("gc-cons-percentage", &Vgc_cons_percentage,
+ doc: /* *Portion of the heap used for allocation.
+Garbage collection can happen automatically once this portion of the heap
+has been allocated since the last garbage collection.
+If this portion is smaller than `gc-cons-threshold', this is ignored. */);
+ Vgc_cons_percentage = make_float (0.1);
DEFVAR_INT ("pure-bytes-used", &pure_bytes_used,
doc: /* Number of bytes of sharable Lisp data allocated so far.
*/);
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