Permalink
Browse files

Re: stuff related to malloc.c

To: jhi@iki.fi
Cc: Carl_Adler@idx.com, perl5-porters@perl.org
Message-Id: <199812130039.TAA21704@monk.mps.ohio-state.edu>

p4raw-id: //depot/cfgperl@2475
  • Loading branch information...
Ilya Zakharevich authored and jhi committed Dec 12, 1998
1 parent a6968aa commit 5bbd1ef51ee0ebfa370a7a454db07f0fabb74b4c
Showing with 43 additions and 15 deletions.
  1. +43 −15 malloc.c
View
@@ -63,6 +63,9 @@
# Which allocator to use if PERL_SBRK_VIA_MALLOC
SYSTEM_ALLOC(a) malloc(a)
+ # Minimal alignment (power of 2) of SYSTEM_ALLOC
+ SYSTEM_ALLOC_ALIGNMENT MEM_ALIGNBYTES
+
# Disable memory overwrite checking with DEBUGGING. Memory and speed
# optimization, error reporting pessimization.
NO_RCHECK undef
@@ -134,6 +137,9 @@
# Type returned by free()
Free_t void
+ # Very fatal condition reporting function (cannot call any )
+ fatalcroak(arg) write(2,arg,strlen(arg)) + exit(2)
+
# Fatal error reporting function
croak(format, arg) warn(idem) + exit(1)
@@ -285,6 +291,10 @@
# define MALLOC_UNLOCK MUTEX_UNLOCK(&PL_malloc_mutex)
#endif
+# ifndef fatalcroak /* make depend */
+# define fatalcroak(mess) (write(2, (mess), strlen(mess)), exit(2))
+# endif
+
#ifdef DEBUGGING
# undef DEBUG_m
# define DEBUG_m(a) if (PL_debug & 128) a
@@ -567,12 +577,18 @@ static u_short blk_shift[LOG_OF_MIN_ARENA * BUCKETS_PER_POW2] =
# endif
};
+# define NEEDED_ALIGNMENT 0x800 /* 2k boundaries */
+# define WANTED_ALIGNMENT 0x800 /* 2k boundaries */
+
#else /* !PACK_MALLOC */
# define OV_MAGIC(block,bucket) (block)->ov_magic
# define OV_INDEX(block) (block)->ov_index
# define CHUNK_SHIFT 1
# define MAX_PACKED -1
+# define NEEDED_ALIGNMENT MEM_ALIGNBYTES
+# define WANTED_ALIGNMENT 0x400 /* 1k boundaries */
+
#endif /* !PACK_MALLOC */
#define M_OVERHEAD (sizeof(union overhead) + RSLOP)
@@ -744,7 +760,7 @@ emergency_sbrk(MEM_SIZE size)
/* Got it, now detach SvPV: */
pv = SvPV(sv, n_a);
/* Check alignment: */
- if (((UV)(pv - sizeof(union overhead))) & ((1<<LOG_OF_MIN_ARENA) - 1)) {
+ if (((UV)(pv - sizeof(union overhead))) & (NEEDED_ALIGNMENT - 1)) {
PerlIO_puts(PerlIO_stderr(),"Bad alignment of $^M!\n");
return (char *)-1; /* die die die */
}
@@ -1079,11 +1095,10 @@ getpages(int needed, int *nblksp, int bucket)
#ifndef atarist /* on the atari we dont have to worry about this */
# ifndef I286 /* The sbrk(0) call on the I286 always returns the next segment */
-
- /* CHUNK_SHIFT is 1 for PACK_MALLOC, 0 otherwise. */
- if ((UV)cp & (0x7FF >> CHUNK_SHIFT)) { /* Not aligned. */
- slack = (0x800 >> CHUNK_SHIFT)
- - ((UV)cp & (0x7FF >> CHUNK_SHIFT));
+ /* WANTED_ALIGNMENT may be more than NEEDED_ALIGNMENT, but this may
+ improve performance of memory access. */
+ if ((UV)cp & (WANTED_ALIGNMENT - 1)) { /* Not aligned. */
+ slack = WANTED_ALIGNMENT - ((UV)cp & (WANTED_ALIGNMENT - 1));
add += slack;
}
# endif
@@ -1106,7 +1121,7 @@ getpages(int needed, int *nblksp, int bucket)
#ifdef PACK_MALLOC
if (slack) {
MALLOC_UNLOCK;
- croak("%s", "panic: Off-page sbrk");
+ fatalcroak("panic: Off-page sbrk\n");
}
#endif
if (sbrked_remains) {
@@ -1143,19 +1158,26 @@ getpages(int needed, int *nblksp, int bucket)
* and deduct from block count to reflect.
*/
+# if NEEDED_ALIGNMENT > MEM_ALIGNBYTES
+ if ((UV)ovp & (NEEDED_ALIGNMENT - 1))
+ fatalcroak("Misalignment of sbrk()\n");
+ else
+# endif
#ifndef I286 /* Again, this should always be ok on an 80286 */
- if ((UV)ovp & 7) {
- ovp = (union overhead *)(((UV)ovp + 8) & ~7);
+ if ((UV)ovp & (MEM_ALIGNBYTES - 1)) {
DEBUG_m(PerlIO_printf(Perl_debug_log,
"fixing sbrk(): %d bytes off machine alignement\n",
- (int)((UV)ovp & 7)));
+ (int)((UV)ovp & (MEM_ALIGNBYTES - 1))));
+ ovp = (union overhead *)(((UV)ovp + MEM_ALIGNBYTES) &
+ (MEM_ALIGNBYTES - 1));
(*nblksp)--;
# if defined(DEBUGGING_MSTATS)
/* This is only approx. if TWO_POT_OPTIMIZE: */
- sbrk_slack += (1 << bucket);
+ sbrk_slack += (1 << (bucket >> BUCKET_POW2_SHIFT));
# endif
}
#endif
+ ; /* Finish `else' */
sbrked_remains = require - needed;
last_op = cp;
}
@@ -1717,7 +1739,7 @@ dump_mstats(char *s)
*
* 980701 Dominic Dunlop <domo@computer.org>
*/
-# define SYSTEM_ALLOC(a) ((void *)(((unsigned)malloc((a)+6)+6)&~7))
+# define SYSTEM_ALLOC_ALIGNMENT 2
# endif
# ifdef PERL_SBRK_VIA_MALLOC
@@ -1738,6 +1760,9 @@ dump_mstats(char *s)
# ifndef SYSTEM_ALLOC
# define SYSTEM_ALLOC(a) malloc(a)
# endif
+# ifndef SYSTEM_ALLOC_ALIGNMENT
+# define SYSTEM_ALLOC_ALIGNMENT MEM_ALIGNBYTES
+# endif
# endif /* PERL_SBRK_VIA_MALLOC */
@@ -1771,10 +1796,13 @@ Perl_sbrk(int size)
size = PERLSBRK_64_K;
small = 1;
}
+# if NEEDED_ALIGNMENT > SYSTEM_ALLOC_ALIGNMENT
+ size += NEEDED_ALIGNMENT - SYSTEM_ALLOC_ALIGNMENT;
+# endif
got = (IV)SYSTEM_ALLOC(size);
-#ifdef PACK_MALLOC
- got = (got + 0x7ff) & ~0x7ff;
-#endif
+# if NEEDED_ALIGNMENT > SYSTEM_ALLOC_ALIGNMENT
+ got = (got + NEEDED_ALIGNMENT - 1) & (NEEDED_ALIGNMENT - 1);
+# endif
if (small) {
/* Chunk is small, register the rest for future allocs. */
Perl_sbrk_oldchunk = got + reqsize;

0 comments on commit 5bbd1ef

Please sign in to comment.