diff options
Diffstat (limited to 'boehm-gc/include/private/gcconfig.h')
| -rw-r--r-- | boehm-gc/include/private/gcconfig.h | 13 |
1 files changed, 11 insertions, 2 deletions
diff --git a/boehm-gc/include/private/gcconfig.h b/boehm-gc/include/private/gcconfig.h index 4c4bca31222..045617a1d7b 100644 --- a/boehm-gc/include/private/gcconfig.h +++ b/boehm-gc/include/private/gcconfig.h @@ -386,6 +386,11 @@ * to the nearest plausible page boundary, and use that instead * of STACKBOTTOM. * + * Gustavo Rodriguez-Rivera points out that on most (all?) Unix machines, + * the value of environ is a pointer that can serve as STACKBOTTOM. + * I expect that HEURISTIC2 can be replaced by this approach, which + * interferes far less with debugging. + * * If no expression for STACKBOTTOM can be found, and neither of the above * heuristics are usable, the collector can still be used with all of the above * undefined, provided one of the following is done: @@ -553,6 +558,7 @@ /* This was 2, but that didn't sound right. */ # define OS_TYPE "LINUX" # define HEURISTIC1 +# define DYNAMIC_LOADING # undef STACK_GRAN # define STACK_GRAN 0x10000000 /* Stack usually starts at 0x80000000 */ @@ -990,7 +996,11 @@ /* this.) */ # define STACKBOTTOM ((ptr_t) 0x7b033000) /* from /etc/conf/h/param.h */ # else -# define HEURISTIC2 + /* Gustavo Rodriguez-Rivera suggested changing HEURISTIC2 */ + /* to this. We'll probably do this on other platforms, too. */ + /* For now I'll use it where I can test it. */ + extern char ** environ; +# define STACKBOTTOM ((ptr_t)environ) # endif # define STACK_GROWS_UP # define DYNAMIC_LOADING @@ -1076,7 +1086,6 @@ /* Requires Linux 2.3.47 or later. */ extern int _end; # define DATAEND (&_end) - /* PREFETCH appears to have a large performance impact. */ # define PREFETCH(x) \ __asm__ (" lfetch [%0]": : "r"((void *)(x))) # define PREFETCH_FOR_WRITE(x) \ |