Front page | perl.perl5.porters |
Postings from June 2003
Re: your malloc patches
Thread Previous
|
Thread Next
From:
Ilya Zakharevich
Date:
June 27, 2003 06:54
Subject:
Re: your malloc patches
Message ID:
20030627135406.GA8914@math.berkeley.edu
On Fri, Jun 27, 2003 at 01:37:12PM +0300, Jarkko Hietaniemi wrote:
> Just to avoid any possible mixups, grab the very latest bleadperl
> malloc.c from
>
> http://www.iki.fi/jhi/malloc.c
>
> (it's the @19834 version I mentioned earlier)
Done.
This patch:
a) changes names of macros (to hopefully less confusing ones);
b) adds more comments;
c) changes some 3's to (RMAGIC_SZ-1);
d) fixes FILLCHECK_... which was checking 12 bytes less than intended.
Yours,
Ilya
P.S. Might it be that "c" can fix some ports where mymalloc would not
work? I have no idea...
--- ./malloc.c.orig Fri Jun 27 14:24:40 2003
+++ ./malloc.c Fri Jun 27 14:25:07 2003
@@ -576,6 +576,7 @@ union overhead {
u_char ovu_index; /* bucket # */
u_char ovu_magic; /* magic number */
#ifdef RCHECK
+ /* Subtract one to fit into u_short for an extra bucket */
u_short ovu_size; /* block size (requested + overhead - 1) */
u_int ovu_rmagic; /* range magic number */
#endif
@@ -591,14 +592,14 @@ union overhead {
#define RMAGIC_C 0x55 /* magic # on range info */
#ifdef RCHECK
-# define RSLOP sizeof (u_int)
+# define RMAGIC_SZ sizeof (u_int) /* Overhead at end of bucket */
# ifdef TWO_POT_OPTIMIZE
# define MAX_SHORT_BUCKET (12 * BUCKETS_PER_POW2) /* size-1 fits in short */
# else
# define MAX_SHORT_BUCKET (13 * BUCKETS_PER_POW2)
# endif
#else
-# define RSLOP 0
+# define RMAGIC_SZ 0
#endif
#if !defined(PACK_MALLOC) && defined(BUCKETS_ROOT2)
@@ -634,15 +635,16 @@ static u_short buck_size[MAX_BUCKET_BY_T
{
0, 0, 0, 0, 4, 4, 8, 12, 16, 24, 32, 48, 64, 80,
};
-# define BUCKET_SIZE(i) ((i) % 2 ? buck_size[i] : (1 << ((i) >> BUCKET_POW2_SHIFT)))
+# define BUCKET_SIZE_NO_SURPLUS(i) ((i) % 2 ? buck_size[i] : (1 << ((i) >> BUCKET_POW2_SHIFT)))
# define BUCKET_SIZE_REAL(i) ((i) <= MAX_BUCKET_BY_TABLE \
? buck_size[i] \
: ((1 << ((i) >> BUCKET_POW2_SHIFT)) \
- MEM_OVERHEAD(i) \
+ POW2_OPTIMIZE_SURPLUS(i)))
#else
-# define BUCKET_SIZE(i) (1 << ((i) >> BUCKET_POW2_SHIFT))
-# define BUCKET_SIZE_REAL(i) (BUCKET_SIZE(i) - MEM_OVERHEAD(i) + POW2_OPTIMIZE_SURPLUS(i))
+# define BUCKET_SIZE_NO_SURPLUS(i) (1 << ((i) >> BUCKET_POW2_SHIFT))
+# define BUCKET_SIZE(i) (BUCKET_SIZE_NO_SURPLUS(i) + POW2_OPTIMIZE_SURPLUS(i))
+# define BUCKET_SIZE_REAL(i) (BUCKET_SIZE(i) - MEM_OVERHEAD(i))
#endif
@@ -787,7 +789,7 @@ static u_short buck_size[MAX_BUCKET_BY_T
#ifdef IGNORE_SMALL_BAD_FREE
#define FIRST_BUCKET_WITH_CHECK (6 * BUCKETS_PER_POW2) /* 64 */
# define N_BLKS(bucket) ( (bucket) < FIRST_BUCKET_WITH_CHECK \
- ? ((1<<LOG_OF_MIN_ARENA) - 1)/BUCKET_SIZE(bucket) \
+ ? ((1<<LOG_OF_MIN_ARENA) - 1)/BUCKET_SIZE_NO_SURPLUS(bucket) \
: n_blks[bucket] )
#else
# define N_BLKS(bucket) n_blks[bucket]
@@ -810,7 +812,7 @@ static u_short n_blks[LOG_OF_MIN_ARENA *
#ifdef IGNORE_SMALL_BAD_FREE
# define BLK_SHIFT(bucket) ( (bucket) < FIRST_BUCKET_WITH_CHECK \
? ((1<<LOG_OF_MIN_ARENA) \
- - BUCKET_SIZE(bucket) * N_BLKS(bucket)) \
+ - BUCKET_SIZE_NO_SURPLUS(bucket) * N_BLKS(bucket)) \
: blk_shift[bucket])
#else
# define BLK_SHIFT(bucket) blk_shift[bucket]
@@ -851,7 +853,7 @@ static u_short blk_shift[LOG_OF_MIN_AREN
#endif /* !PACK_MALLOC */
-#define M_OVERHEAD (sizeof(union overhead) + RSLOP)
+#define M_OVERHEAD (sizeof(union overhead) + RMAGIC_SZ) /* overhead at start+end */
#ifdef PACK_MALLOC
# define MEM_OVERHEAD(bucket) \
@@ -1510,7 +1512,7 @@ Perl_malloc(register size_t nbytes)
(long)size));
FILLCHECK_DEADBEEF((unsigned char*)(p + CHUNK_SHIFT),
- BUCKET_SIZE_REAL(bucket));
+ BUCKET_SIZE_REAL(bucket) + RMAGIC_SZ);
#ifdef IGNORE_SMALL_BAD_FREE
if (bucket >= FIRST_BUCKET_WITH_CHECK)
@@ -1530,13 +1532,14 @@ Perl_malloc(register size_t nbytes)
nbytes = size + M_OVERHEAD;
p->ov_size = nbytes - 1;
- if ((i = nbytes & 3)) {
- i = 4 - i;
- while (i--)
- *((char *)((caddr_t)p + nbytes - RSLOP + i)) = RMAGIC_C;
+ if ((i = nbytes & (RMAGIC_SZ-1))) {
+ i = RMAGIC_SZ - i;
+ while (i--) /* nbytes - RMAGIC_SZ is end of alloced area */
+ ((caddr_t)p + nbytes - RMAGIC_SZ)[i] = RMAGIC_C;
}
- nbytes = (nbytes + 3) &~ 3;
- *((u_int *)((caddr_t)p + nbytes - RSLOP)) = RMAGIC;
+ /* Same at RMAGIC_SZ-aligned RMAGIC */
+ nbytes = (nbytes + RMAGIC_SZ - 1) & ~(RMAGIC_SZ - 1);
+ ((u_int *)((caddr_t)p + nbytes))[-1] = RMAGIC;
}
FILL_FEEDADAD((unsigned char *)(p + CHUNK_SHIFT), size);
#endif
@@ -1631,7 +1634,7 @@ get_from_bigger_buckets(int bucket, MEM_
nmalloc[bucket]--;
start_slack -= M_OVERHEAD;
#endif
- add_to_chain(ret, (BUCKET_SIZE(bucket) +
+ add_to_chain(ret, (BUCKET_SIZE_NO_SURPLUS(bucket) +
POW2_OPTIMIZE_SURPLUS(bucket)),
size);
return ret;
@@ -1936,7 +1939,7 @@ morecore(register int bucket)
* Add new memory allocated to that on
* free list for this hash bucket.
*/
- siz = BUCKET_SIZE(bucket);
+ siz = BUCKET_SIZE_NO_SURPLUS(bucket); /* No surplus if nblks > 1 */
#ifdef PACK_MALLOC
*(u_char*)ovp = bucket; /* Fill index. */
if (bucket <= MAX_PACKED) {
@@ -2047,19 +2050,22 @@ Perl_mfree(void *mp)
int i;
MEM_SIZE nbytes = ovp->ov_size + 1;
- if ((i = nbytes & 3)) {
- i = 4 - i;
- while (i--) {
- ASSERT(*((char *)((caddr_t)ovp + nbytes - RSLOP + i))
- == RMAGIC_C, "chunk's tail overwrite");
+ if ((i = nbytes & (RMAGIC_SZ-1))) {
+ i = RMAGIC_SZ - i;
+ while (i--) { /* nbytes - RMAGIC_SZ is end of alloced area */
+ ASSERT(((caddr_t)ovp + nbytes - RMAGIC_SZ)[i] == RMAGIC_C,
+ "chunk's tail overwrite");
}
}
- nbytes = (nbytes + 3) &~ 3;
- ASSERT(*(u_int *)((caddr_t)ovp + nbytes - RSLOP) == RMAGIC, "chunk's tail overwrite");
- FILLCHECK_DEADBEEF((unsigned char*)((caddr_t)ovp + nbytes - RSLOP + sizeof(u_int)),
- BUCKET_SIZE_REAL(OV_INDEX(ovp)) - (nbytes - RSLOP + sizeof(u_int)));
+ /* Same at RMAGIC_SZ-aligned RMAGIC */
+ nbytes = (nbytes + (RMAGIC_SZ-1)) & ~(RMAGIC_SZ-1);
+ ASSERT(((u_int *)((caddr_t)ovp + nbytes))[-1] == RMAGIC,
+ "chunk's tail overwrite");
+ FILLCHECK_DEADBEEF((unsigned char*)((caddr_t)ovp + nbytes),
+ BUCKET_SIZE(OV_INDEX(ovp)) - nbytes);
}
- FILL_DEADBEEF((unsigned char*)(ovp+1), BUCKET_SIZE_REAL(OV_INDEX(ovp)));
+ FILL_DEADBEEF((unsigned char*)(ovp+CHUNK_SHIFT),
+ BUCKET_SIZE_REAL(OV_INDEX(ovp)) + RMAGIC_SZ);
ovp->ov_rmagic = RMAGIC - 1;
#endif
ASSERT(OV_INDEX(ovp) < NBUCKETS, "chunk's head overwrite");
@@ -2189,22 +2195,24 @@ Perl_realloc(void *mp, size_t nbytes)
if (OV_INDEX(ovp) <= MAX_SHORT_BUCKET) {
int i, nb = ovp->ov_size + 1;
- if ((i = nb & 3)) {
- i = 4 - i;
- while (i--) {
- ASSERT(*((char *)((caddr_t)ovp + nb - RSLOP + i)) == RMAGIC_C, "chunk's tail overwrite");
+ if ((i = nb & (RMAGIC_SZ-1))) {
+ i = RMAGIC_SZ - i;
+ while (i--) { /* nb - RMAGIC_SZ is end of alloced area */
+ ASSERT(((caddr_t)ovp + nb - RMAGIC_SZ)[i] == RMAGIC_C, "chunk's tail overwrite");
}
}
- nb = (nb + 3) &~ 3;
- ASSERT(*(u_int *)((caddr_t)ovp + nb - RSLOP) == RMAGIC, "chunk's tail overwrite");
- FILLCHECK_DEADBEEF((unsigned char*)((caddr_t)ovp + nb - RSLOP + sizeof(u_int)),
- BUCKET_SIZE_REAL(OV_INDEX(ovp)) - (nb - RSLOP + sizeof(u_int)));
+ /* Same at RMAGIC_SZ-aligned RMAGIC */
+ nb = (nb + (RMAGIC_SZ-1)) & ~(RMAGIC_SZ-1);
+ ASSERT(((u_int *)((caddr_t)ovp + nb))[-1] == RMAGIC,
+ "chunk's tail overwrite");
+ FILLCHECK_DEADBEEF((unsigned char*)((caddr_t)ovp + nb),
+ BUCKET_SIZE(OV_INDEX(ovp)) - nb);
if (nbytes > ovp->ov_size + 1 - M_OVERHEAD)
FILL_FEEDADAD((unsigned char*)cp + ovp->ov_size + 1 - M_OVERHEAD,
nbytes - (ovp->ov_size + 1 - M_OVERHEAD));
else
FILL_DEADBEEF((unsigned char*)cp + nbytes,
- nb - M_OVERHEAD + RSLOP - nbytes);
+ nb - M_OVERHEAD + RMAGIC_SZ - nbytes);
/*
* Convert amount of memory requested into
* closest block size stored in hash buckets
@@ -2213,14 +2221,15 @@ Perl_realloc(void *mp, size_t nbytes)
*/
nbytes += M_OVERHEAD;
ovp->ov_size = nbytes - 1;
- if ((i = nbytes & 3)) {
- i = 4 - i;
- while (i--)
- *((char *)((caddr_t)ovp + nbytes - RSLOP + i))
+ if ((i = nbytes & (RMAGIC_SZ-1))) {
+ i = RMAGIC_SZ - i;
+ while (i--) /* nbytes - RMAGIC_SZ is end of alloced area */
+ ((caddr_t)ovp + nbytes - RMAGIC_SZ)[i]
= RMAGIC_C;
}
- nbytes = (nbytes + 3) &~ 3;
- *((u_int *)((caddr_t)ovp + nbytes - RSLOP)) = RMAGIC;
+ /* Same at RMAGIC_SZ-aligned RMAGIC */
+ nbytes = (nbytes + (RMAGIC_SZ-1)) & ~(RMAGIC_SZ - 1);
+ ((u_int *)((caddr_t)ovp + nbytes))[-1] = RMAGIC;
}
#endif
res = cp;
@@ -2337,7 +2346,7 @@ Perl_malloced_size(void *p)
if (bucket <= MAX_SHORT_BUCKET) {
MEM_SIZE size = BUCKET_SIZE_REAL(bucket);
ovp->ov_size = size + M_OVERHEAD - 1;
- *((u_int *)((caddr_t)ovp + size + M_OVERHEAD - RSLOP)) = RMAGIC;
+ *((u_int *)((caddr_t)ovp + size + M_OVERHEAD - RMAGIC_SZ)) = RMAGIC;
}
#endif
return BUCKET_SIZE_REAL(bucket);
@@ -2393,7 +2402,7 @@ Perl_get_mstats(pTHX_ perl_mstats_t *buf
for (i = MIN_BUCKET ; i < NBUCKETS; i++) {
if (i >= buflen)
break;
- buf->bucket_mem_size[i] = BUCKET_SIZE(i);
+ buf->bucket_mem_size[i] = BUCKET_SIZE_NO_SURPLUS(i);
buf->bucket_available_size[i] = BUCKET_SIZE_REAL(i);
}
}
@@ -2425,9 +2434,9 @@ Perl_dump_mstats(pTHX_ char *s)
"Memory allocation statistics %s (buckets %"IVdf"(%"IVdf")..%"IVdf"(%"IVdf")\n",
s,
(IV)BUCKET_SIZE_REAL(MIN_BUCKET),
- (IV)BUCKET_SIZE(MIN_BUCKET),
+ (IV)BUCKET_SIZE_NO_SURPLUS(MIN_BUCKET),
(IV)BUCKET_SIZE_REAL(buffer.topbucket),
- (IV)BUCKET_SIZE(buffer.topbucket));
+ (IV)BUCKET_SIZE_NO_SURPLUS(buffer.topbucket));
PerlIO_printf(Perl_error_log, "%8"IVdf" free:", buffer.totfree);
for (i = MIN_EVEN_REPORT; i <= buffer.topbucket; i += BUCKETS_PER_POW2) {
PerlIO_printf(Perl_error_log,
Thread Previous
|
Thread Next