src/chunk.c

#define	JEMALLOC_CHUNK_C_
#include "jemalloc/internal/jemalloc_internal.h"

/******************************************************************************/
/* Data. */

const char	*opt_dss = DSS_DEFAULT;
size_t		opt_lg_chunk = 0;

/* Various chunk-related settings. */
size_t		chunksize;
size_t		chunksize_mask; /* (chunksize - 1). */
size_t		chunk_npages;

/******************************************************************************/

bool
chunk_boot(void)
{
#ifdef _WIN32
	SYSTEM_INFO info;
	GetSystemInfo(&info);

	/*
	 * Verify actual page size is equal to or an integral multiple of
	 * configured page size.
	 */
	if (info.dwPageSize & ((1U << LG_PAGE) - 1))
		return (true);

	/*
	 * Configure chunksize (if not set) to match granularity (usually 64K),
	 * so pages_map will always take fast path.
	 */
	if (!opt_lg_chunk) {
		opt_lg_chunk = ffs_u((unsigned)info.dwAllocationGranularity)
		    - 1;
	}
#else
	if (!opt_lg_chunk)
		opt_lg_chunk = LG_CHUNK_DEFAULT;
#endif

	/* Set variables according to the value of opt_lg_chunk. */
	chunksize = (ZU(1) << opt_lg_chunk);
	assert(chunksize >= PAGE);
	chunksize_mask = chunksize - 1;
	chunk_npages = (chunksize >> LG_PAGE);

	return (false);
}