diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 359f0cfb79e8b401534a22b6cada1bc4702f30cc..8ce8ab9705d53941928861c9d36bd3dd6dd2d923 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,12 @@
+2004-08-09 Geoffrey Keating <geoffk@apple.com>
+
+ * ggc-common.c (ggc_rlimit_bound): Don't check RSS limit.
+ Check DATA limit only if there's no AS limit. Ignore insanely
+ low DATA limits.
+ (ggc_min_heapsize_heuristic): Don't divide AS or RSS limits by 8,
+ but take care that the AS limit isn't overrun.
+ * doc/invoke.texi: Update documentation of min-heapsize parameter.
+
2004-08-09 Jeff Law <law@redhat.com>
* Makefile.in (OBJC-common): Add tree-ssa-threadupdate.c
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index 0018fc601837b4fbca27c449d7d21bd769278611..bf41ffb426a636bfc9596e7e059eab3fee26b365 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -5310,7 +5310,7 @@ generation.
The default is 30% + 70% * (RAM/1GB) with an upper bound of 100% when
RAM >= 1GB. If @code{getrlimit} is available, the notion of "RAM" is
-the smallest of actual RAM, RLIMIT_RSS, RLIMIT_DATA and RLIMIT_AS. If
+the smallest of actual RAM and RLIMIT_DATA or RLIMIT_AS. If
GCC is not able to calculate RAM on a particular platform, the lower
bound of 30% is used. Setting this parameter and
@option{ggc-min-heapsize} to zero causes a full collection to occur at
@@ -5325,14 +5325,14 @@ by @option{ggc-min-expand}% beyond @option{ggc-min-heapsize}. Again,
tuning this may improve compilation speed, and has no effect on code
generation.
-The default is RAM/8, with a lower bound of 4096 (four megabytes) and an
-upper bound of 131072 (128 megabytes). If @code{getrlimit} is
-available, the notion of "RAM" is the smallest of actual RAM,
-RLIMIT_RSS, RLIMIT_DATA and RLIMIT_AS. If GCC is not able to calculate
-RAM on a particular platform, the lower bound is used. Setting this
-parameter very large effectively disables garbage collection. Setting
-this parameter and @option{ggc-min-expand} to zero causes a full
-collection to occur at every opportunity.
+The default is the smaller of RAM/8, RLIMIT_RSS, or a limit which
+tries to ensure that RLIMIT_DATA or RLIMIT_AS are not exceeded, but
+with a lower bound of 4096 (four megabytes) and an upper bound of
+131072 (128 megabytes). If GCC is not able to calculate RAM on a
+particular platform, the lower bound is used. Setting this parameter
+very large effectively disables garbage collection. Setting this
+parameter and @option{ggc-min-expand} to zero causes a full collection
+to occur at every opportunity.
@item max-reload-search-insns
The maximum number of instruction reload should look backward for equivalent
diff --git a/gcc/ggc-common.c b/gcc/ggc-common.c
index cc0dc93be84177b531ffa64699980d571f83a927..5c99175d663e5bdda0bcf2293291fd674a9a955b 100644
--- a/gcc/ggc-common.c
+++ b/gcc/ggc-common.c
@@ -669,30 +669,34 @@ mmap_gt_pch_use_address (void *base, size_t size, int fd, size_t offset)
}
#endif /* HAVE_MMAP_FILE */
-/* Modify the bound based on rlimits. Keep the smallest number found. */
+/* Modify the bound based on rlimits. */
static double
ggc_rlimit_bound (double limit)
{
#if defined(HAVE_GETRLIMIT)
struct rlimit rlim;
-# ifdef RLIMIT_RSS
- if (getrlimit (RLIMIT_RSS, &rlim) == 0
+# if defined (RLIMIT_AS)
+ /* RLIMIT_AS is what POSIX says is the limit on mmap. Presumably
+ any OS which has RLIMIT_AS also has a working mmap that GCC will use. */
+ if (getrlimit (RLIMIT_AS, &rlim) == 0
&& rlim.rlim_cur != (rlim_t) RLIM_INFINITY
&& rlim.rlim_cur < limit)
limit = rlim.rlim_cur;
-# endif
-# ifdef RLIMIT_DATA
+# elif defined (RLIMIT_DATA)
+ /* ... but some older OSs bound mmap based on RLIMIT_DATA, or we
+ might be on an OS that has a broken mmap. (Others don't bound
+ mmap at all, apparently.) */
if (getrlimit (RLIMIT_DATA, &rlim) == 0
&& rlim.rlim_cur != (rlim_t) RLIM_INFINITY
- && rlim.rlim_cur < limit)
- limit = rlim.rlim_cur;
-# endif
-# ifdef RLIMIT_AS
- if (getrlimit (RLIMIT_AS, &rlim) == 0
- && rlim.rlim_cur != (rlim_t) RLIM_INFINITY
- && rlim.rlim_cur < limit)
+ && rlim.rlim_cur < limit
+ /* Darwin has this horribly bogus default setting of
+ RLIMIT_DATA, to 6144Kb. No-one notices because RLIMIT_DATA
+ appears to be ignored. Ignore such silliness. If a limit
+ this small was actually effective for mmap, GCC wouldn't even
+ start up. */
+ && rlim.rlim_cur >= 8 * 1024 * 1024)
limit = rlim.rlim_cur;
-# endif
+# endif /* RLIMIT_AS or RLIMIT_DATA */
#endif /* HAVE_GETRLIMIT */
return limit;
@@ -721,20 +725,39 @@ ggc_min_expand_heuristic (void)
int
ggc_min_heapsize_heuristic (void)
{
- double min_heap_kbytes = physmem_total();
-
- /* Adjust for rlimits. */
- min_heap_kbytes = ggc_rlimit_bound (min_heap_kbytes);
+ double phys_kbytes = physmem_total();
+ double limit_kbytes = ggc_rlimit_bound (phys_kbytes * 2);
- min_heap_kbytes /= 1024; /* Convert to Kbytes. */
+ phys_kbytes /= 1024; /* Convert to Kbytes. */
+ limit_kbytes /= 1024;
/* The heuristic is RAM/8, with a lower bound of 4M and an upper
bound of 128M (when RAM >= 1GB). */
- min_heap_kbytes /= 8;
- min_heap_kbytes = MAX (min_heap_kbytes, 4 * 1024);
- min_heap_kbytes = MIN (min_heap_kbytes, 128 * 1024);
+ phys_kbytes /= 8;
+
+#if defined(HAVE_GETRLIMIT) && defined (RLIMIT_RSS)
+ /* Try not to overrun the RSS limit while doing garbage collection.
+ The RSS limit is only advisory, so no margin is subtracted. */
+ {
+ struct rlimit rlim;
+ if (getrlimit (RLIMIT_RSS, &rlim) == 0
+ && rlim.rlim_cur != (rlim_t) RLIM_INFINITY)
+ phys_kbytes = MIN (phys_kbytes, rlim.rlim_cur / 1024);
+ }
+# endif
+
+ /* Don't blindly run over our data limit; do GC at least when the
+ *next* GC would be within 16Mb of the limit. If GCC does hit the
+ data limit, compilation will fail, so this tries to be
+ conservative. */
+ limit_kbytes = MAX (0, limit_kbytes - 16 * 1024);
+ limit_kbytes = (limit_kbytes * 100) / (110 + ggc_min_expand_heuristic());
+ phys_kbytes = MIN (phys_kbytes, limit_kbytes);
+
+ phys_kbytes = MAX (phys_kbytes, 4 * 1024);
+ phys_kbytes = MIN (phys_kbytes, 128 * 1024);
- return min_heap_kbytes;
+ return phys_kbytes;
}
void