7:01 a.m.
This one I'm not committing quite yet, as it is a (somewhat) user-visible
change. I'm interested in comments. With this change, GC will not happen
until at least 40% (a random guess) of current Lisp-object memory has been
allocated. The purpose of this is to make GC time be a constant amortized
percentage of total run time, regardless of how big XEmacs is. (Currently,
GC time will become a progressively larger percent of total time as the
size of XEmacs increases.) Note that the lower bound in gc-cons-threshold
(500K) still applies.
ben
src/ChangeLog addition:
2005-09-27 Ben Wing <ben(a)xemacs.org>
* alloc.c (garbage_collect_1):
Avoid use of reserved C++ `catch'.
* alloc.c:
* alloc.c (gc_plist_hack):
* alloc.c (HACK_O_MATIC):
* alloc.c (Fgarbage_collect):
* alloc.c (Ftotal_memory_usage):
* alloc.c (Flisp_object_memory_usage):
* alloc.c (recompute_need_to_garbage_collect):
* alloc.c (common_init_alloc_early):
* alloc.c (syms_of_alloc):
* alloc.c (vars_of_alloc):
Rename underused `memory-usage' to `total-memory-usage'.
Add `lisp-object-memory-usage'. Reimplement `gc-cons-percentage'
to be a percentage of total Lisp object allocation (not total
memory of all sorts, which is hard to calculate in any case) and
give it a preliminary value of 40%. Use EMACS_INT instead of
int in a couple of places.
build source patch:
Diff command: bash -ci "cvs-diff --show-c-function -no-changelog "
Files affected: src/alloc.c
Tue Sep 27 00:52:23 CDT 2005
Index: src/alloc.c
===================================================================
RCS file: /pack/xemacscvs/XEmacs/xemacs/src/alloc.c,v
retrieving revision 1.113
diff -u -p -r1.113 alloc.c
--- src/alloc.c 2005/05/15 16:38:11 1.113
+++ src/alloc.c 2005/09/27 05:52:48
＠＠ -1,7 +1,7 ＠＠
/* Storage allocation and gc for XEmacs Lisp interpreter.
Copyright (C) 1985-1998 Free Software Foundation, Inc.
Copyright (C) 1995 Sun Microsystems, Inc.
- Copyright (C) 1995, 1996, 2001, 2002, 2003, 2004 Ben Wing.
+ Copyright (C) 1995, 1996, 2001, 2002, 2003, 2004, 2005 Ben Wing.
This file is part of XEmacs.
＠＠ -94,6 +94,8 ＠＠ static Fixnum debug_allocation_backtrace
/* Number of bytes of consing done since the last gc */
static EMACS_INT consing_since_gc;
EMACS_UINT total_consing;
+EMACS_INT total_gc_usage;
+int total_gc_usage_set;
int need_to_garbage_collect;
int need_to_check_c_alloca;
＠＠ -5525,13 +5527,13 ＠＠ garbage_collect_1 (void)
}
{
- struct catchtag *catch;
- for (catch = catchlist; catch; catch = catch->next)
+ struct catchtag *c;
+ for (c = catchlist; c; c = c->next)
{
- mark_object (catch->tag);
- mark_object (catch->val);
- mark_object (catch->actual_tag);
- mark_object (catch->backtrace);
+ mark_object (c->tag);
+ mark_object (c->val);
+ mark_object (c->actual_tag);
+ mark_object (c->backtrace);
}
}
＠＠ -5769,7 +5771,7 ＠＠ Garbage collection happens automatically
/* Debugging aids. */
static Lisp_Object
-gc_plist_hack (const Ascbyte *name, int value, Lisp_Object tail)
+gc_plist_hack (const Ascbyte *name, EMACS_INT value, Lisp_Object tail)
{
/* C doesn't have local functions (or closures, or GC, or readable syntax,
or portable numeric datatypes, or bit-vectors, or characters, or
＠＠ -5778,9 +5780,10 ＠＠ gc_plist_hack (const Ascbyte *name, int
}
#define HACK_O_MATIC(type, name, pl) do { \
- int s = 0; \
+ EMACS_INT s = 0; \
struct type##_block *x = current_##type##_block; \
while (x) { s += sizeof (*x) + MALLOC_OVERHEAD; x = x->prev; } \
+ object_usage += s; \
(pl) = gc_plist_hack ((name), s, (pl)); \
} while (0)
＠＠ -5800,8 +5803,11 ＠＠ Garbage collection happens automatically
Lisp_Object pl = Qnil;
int i;
int gc_count_vector_total_size = 0;
+ EMACS_INT object_usage = 0;
+
garbage_collect_1 ();
+
for (i = 0; i < lrecord_type_count; i++)
{
if (lcrecord_stats[i].bytes_in_use != 0
＠＠ -5818,6 +5824,7 ＠＠ Garbage collection happens automatically
sprintf (buf, "%s-storage", name);
pl = gc_plist_hack (buf, lcrecord_stats[i].bytes_in_use, pl);
+ object_usage += lcrecord_stats[i].bytes_in_use;
/* Okay, simple pluralization check for `symbol-value-varalias' */
if (name[len-1] == 's')
sprintf (buf, "%ses-freed", name);
＠＠ -5895,6 +5902,10 ＠＠ Garbage collection happens automatically
pl = gc_plist_hack ("conses-free", gc_count_num_cons_freelist, pl);
pl = gc_plist_hack ("conses-used", gc_count_num_cons_in_use, pl);
+ /* Record total usage for purposes of determining next GC */
+ total_gc_usage = object_usage;
+ total_gc_usage_set = 1;
+
/* The things we do for backwards-compatibility */
return
list6 (Fcons (make_int (gc_count_num_cons_in_use),
＠＠ -5934,15 +5945,29 ＠＠ The value is divided by 1024 to make sur
}
#endif
-DEFUN ("memory-usage", Fmemory_usage, 0, 0, 0, /*
+DEFUN ("total-memory-usage", Ftotal_memory_usage, 0, 0, 0, /*
Return the total number of bytes used by the data segment in XEmacs.
This may be helpful in debugging XEmacs's memory usage.
+NOTE: This may or may not be accurate! It is hard to determine this
+value in a system-independent fashion.
*/
())
{
return make_int (total_data_usage ());
}
+DEFUN ("lisp-object-memory-usage", Flisp_object_memory_usage, 0, 0, 0, /*
+Return the total number of bytes used for object storage in XEmacs.
+This may be helpful in debugging XEmacs's memory usage.
+This value is only recomputed when garbage collection happens; thus, a
+better value of the real number of bytes used is
+ (+ (lisp-object-memory-usage) (consing-since-gc))
+*/
+ ())
+{
+ return make_int (total_gc_usage);
+}
+
void
recompute_funcall_allocation_flag (void)
{
＠＠ -5961,11 +5986,15 ＠＠ recompute_need_to_garbage_collect (void)
else
need_to_garbage_collect =
(consing_since_gc > gc_cons_threshold
-#if 0 /* #### implement this better */
&&
+#if 0 /* #### implement this better */
(100 * consing_since_gc) / total_data_usage () >=
gc_cons_percentage
-#endif /* 0 */
+#else
+ (!total_gc_usage_set ||
+ (100 * consing_since_gc) / total_gc_usage >=
+ gc_cons_percentage)
+#endif
);
recompute_funcall_allocation_flag ();
}
＠＠ -6220,9 +6249,8 ＠＠ common_init_alloc_early (void)
#else
gc_cons_threshold = 15000; /* debugging */
#endif
- gc_cons_percentage = 0; /* #### 20; Don't have an accurate measure of
- memory usage on Windows; not verified on other
- systems */
+ gc_cons_percentage = 40; /* #### what is optimal? */
+ total_gc_usage_set = 0;
lrecord_uid_counter = 259;
#ifndef MC_ALLOC
debug_string_purity = 0;
＠＠ -6354,7 +6382,8 ＠＠ syms_of_alloc (void)
#if 0
DEFSUBR (Fmemory_limit);
#endif
- DEFSUBR (Fmemory_usage);
+ DEFSUBR (Ftotal_memory_usage);
+ DEFSUBR (Flisp_object_memory_usage);
DEFSUBR (Fconsing_since_gc);
}
＠＠ -6386,26 +6415,22 ＠＠ effective way to check GCPRO problems, b
will be unusable! You almost certainly won't have the patience to wait
long enough to be able to set it back.
-See also `consing-since-gc'.
+See also `consing-since-gc' and `gc-cons-percentage'.
*/ );
DEFVAR_INT ("gc-cons-percentage", &gc_cons_percentage /*
*Percentage of memory allocated between garbage collections.
Garbage collection will happen if this percentage of the total amount of
-memory used for data has been allocated since the last garbage collection.
-However, it will not happen if less than `gc-cons-threshold' bytes have
-been allocated -- this sets an absolute minimum in case very little data
-has been allocated or the percentage is set very low. Set this to 0 to
-have garbage collection always happen after `gc-cons-threshold' bytes have
-been allocated, regardless of current memory usage.
-
-Garbage collection happens automatically when `eval' or `funcall' are
-called. (Note that `funcall' is called implicitly as part of evaluation.)
-By binding this temporarily to a large number, you can effectively
-prevent garbage collection during a part of the program.
+memory used for data (see `lisp-object-memory-usage') has been allocated
+since the last garbage collection. However, it will not happen if less
+than `gc-cons-threshold' bytes have been allocated -- this sets an absolute
+minimum in case very little data has been allocated or the percentage is
+set very low. Set this to 0 to have garbage collection always happen after
+`gc-cons-threshold' bytes have been allocated, regardless of current memory
+usage.
-See also `consing-since-gc'.
+See also `consing-since-gc' and `gc-cons-threshold'.
*/ );
#ifdef DEBUG_XEMACS