Function memstat_sysctl_malloc

tools/libmemstat/memstat_malloc.c:87–257

* Extract malloc(9) statistics from the running kernel, and store all memory * type information in the passed list. For each type, check the list for an * existing entry with the right name/allocator -- if present, update that * entry. Otherwise, add a new entry. On error, the entire list will be * cleared, as entries will be in an inconsistent state. * * To reduce the level of work for a

 * each entry before adding it.
 */
int
memstat_sysctl_malloc(struct memory_type_list *list, int flags)
{
	struct malloc_type_stream_header *mtshp;
	struct malloc_type_header *mthp;
	struct malloc_type_stats *mtsp;
	struct memory_type *mtp;
	int count, hint_dontsearch, i, j, maxcpus;
	char *buffer, *p;
	size_t size;

	hint_dontsearch = LIST_EMPTY(&list->mtl_list);

	/*
	 * Query the number of CPUs, number of malloc types so that we can
	 * guess an initial buffer size.  We loop until we succeed or really
	 * fail.  Note that the value of maxcpus we query using sysctl is not
	 * the version we use when processing the real data -- that is read
	 * from the header.
	 */
retry:
	size = sizeof(maxcpus);
	if (sysctlbyname("kern.smp.maxcpus", &maxcpus, &size, NULL, 0) < 0) {
		if (errno == EACCES || errno == EPERM)
			list->mtl_error = MEMSTAT_ERROR_PERMISSION;
		else
			list->mtl_error = MEMSTAT_ERROR_DATAERROR;
		return (-1);
	}
	if (size != sizeof(maxcpus)) {
		list->mtl_error = MEMSTAT_ERROR_DATAERROR;
		return (-1);
	}

	size = sizeof(count);
	if (sysctlbyname("kern.malloc_count", &count, &size, NULL, 0) < 0) {
		if (errno == EACCES || errno == EPERM)
			list->mtl_error = MEMSTAT_ERROR_PERMISSION;
		else
			list->mtl_error = MEMSTAT_ERROR_VERSION;
		return (-1);
	}
	if (size != sizeof(count)) {
		list->mtl_error = MEMSTAT_ERROR_DATAERROR;
		return (-1);
	}

#ifndef FSTACK
	if (memstat_malloc_zone_init() == -1) {
		list->mtl_error = MEMSTAT_ERROR_VERSION;
		return (-1);
	}
#endif

	size = sizeof(*mthp) + count * (sizeof(*mthp) + sizeof(*mtsp) *
	    maxcpus);

	buffer = malloc(size);