Hi,
This simpifies the lock dance when a free is done for a pointer not in
"my pool". Should reduce lock contention.
Please review & test, especially with multithread heavy apps.
-Otto
Index: malloc.c
===================================================================
RCS file: /cvs/src/lib/libc/stdlib/malloc.c,v
retrieving revision 1.255
diff -u -p -r1.255 malloc.c
--- malloc.c 27 Nov 2018 17:29:55 -0000 1.255
+++ malloc.c 6 Dec 2018 10:26:56 -0000
@@ -1309,14 +1309,14 @@ findpool(void *p, struct dir_info *argpo
}
static void
-ofree(struct dir_info *argpool, void *p, int clear, int check, size_t argsz)
+ofree(struct dir_info **argpool, void *p, int clear, int check, size_t argsz)
{
struct region_info *r;
struct dir_info *pool;
char *saved_function;
size_t sz;
- r = findpool(p, argpool, &pool, &saved_function);
+ r = findpool(p, *argpool, &pool, &saved_function);
REALSIZE(sz, r);
if (check) {
@@ -1405,12 +1405,9 @@ ofree(struct dir_info *argpool, void *p,
}
}
- if (argpool != pool) {
- pool->active--;
+ if (*argpool != pool) {
pool->func = saved_function;
- _MALLOC_UNLOCK(pool->mutex);
- _MALLOC_LOCK(argpool->mutex);
- argpool->active++;
+ *argpool = pool;
}
}
@@ -1433,7 +1430,7 @@ free(void *ptr)
malloc_recurse(d);
return;
}
- ofree(d, ptr, 0, 0, 0);
+ ofree(&d, ptr, 0, 0, 0);
d->active--;
_MALLOC_UNLOCK(d->mutex);
errno = saved_errno;
@@ -1471,7 +1468,7 @@ freezero(void *ptr, size_t sz)
malloc_recurse(d);
return;
}
- ofree(d, ptr, 1, 1, sz);
+ ofree(&d, ptr, 1, 1, sz);
d->active--;
_MALLOC_UNLOCK(d->mutex);
errno = saved_errno;
@@ -1479,7 +1476,7 @@ freezero(void *ptr, size_t sz)
DEF_WEAK(freezero);
static void *
-orealloc(struct dir_info *argpool, void *p, size_t newsz, void *f)
+orealloc(struct dir_info **argpool, void *p, size_t newsz, void *f)
{
struct region_info *r;
struct dir_info *pool;
@@ -1490,14 +1487,14 @@ orealloc(struct dir_info *argpool, void
uint32_t chunknum;
if (p == NULL)
- return omalloc(argpool, newsz, 0, f);
+ return omalloc(*argpool, newsz, 0, f);
if (newsz >= SIZE_MAX - mopts.malloc_guard - MALLOC_PAGESIZE) {
errno = ENOMEM;
return NULL;
}
- r = findpool(p, argpool, &pool, &saved_function);
+ r = findpool(p, *argpool, &pool, &saved_function);
REALSIZE(oldsz, r);
if (mopts.chunk_canaries && oldsz <= MALLOC_MAXCHUNK) {
@@ -1631,7 +1628,7 @@ gotit:
}
if (newsz != 0 && oldsz != 0)
memcpy(q, p, oldsz < newsz ? oldsz : newsz);
- ofree(pool, p, 0, 0, 0);
+ ofree(&pool, p, 0, 0, 0);
ret = q;
} else {
/* oldsz == newsz */
@@ -1641,12 +1638,9 @@ gotit:
ret = p;
}
done:
- if (argpool != pool) {
- pool->active--;
+ if (*argpool != pool) {
pool->func = saved_function;
- _MALLOC_UNLOCK(pool->mutex);
- _MALLOC_LOCK(argpool->mutex);
- argpool->active++;
+ *argpool = pool;
}
return ret;
}
@@ -1669,7 +1663,7 @@ realloc(void *ptr, size_t size)
malloc_recurse(d);
return NULL;
}
- r = orealloc(d, ptr, size, CALLER);
+ r = orealloc(&d, ptr, size, CALLER);
d->active--;
_MALLOC_UNLOCK(d->mutex);
@@ -1730,7 +1724,7 @@ calloc(size_t nmemb, size_t size)
/*DEF_STRONG(calloc);*/
static void *
-orecallocarray(struct dir_info *argpool, void *p, size_t oldsize,
+orecallocarray(struct dir_info **argpool, void *p, size_t oldsize,
size_t newsize, void *f)
{
struct region_info *r;
@@ -1740,12 +1734,12 @@ orecallocarray(struct dir_info *argpool,
size_t sz;
if (p == NULL)
- return omalloc(argpool, newsize, 1, f);
+ return omalloc(*argpool, newsize, 1, f);
if (oldsize == newsize)
return p;
- r = findpool(p, argpool, &pool, &saved_function);
+ r = findpool(p, *argpool, &pool, &saved_function);
REALSIZE(sz, r);
if (sz <= MALLOC_MAXCHUNK) {
@@ -1772,15 +1766,12 @@ orecallocarray(struct dir_info *argpool,
} else
memcpy(newptr, p, newsize);
- ofree(pool, p, 1, 0, oldsize);
+ ofree(&pool, p, 1, 0, oldsize);
done:
- if (argpool != pool) {
- pool->active--;
+ if (*argpool != pool) {
pool->func = saved_function;
- _MALLOC_UNLOCK(pool->mutex);
- _MALLOC_LOCK(argpool->mutex);
- argpool->active++;
+ *argpool = pool;
}
return newptr;
@@ -1883,7 +1874,7 @@ recallocarray(void *ptr, size_t oldnmemb
return NULL;
}
- r = orecallocarray(d, ptr, oldsize, newsize, CALLER);
+ r = orecallocarray(&d, ptr, oldsize, newsize, CALLER);
d->active--;
_MALLOC_UNLOCK(d->mutex);
