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/*
* Copyright (c) 1996 The University of Utah and
* the Computer Systems Laboratory at the University of Utah (CSL).
* All rights reserved.
*
* Permission to use, copy, modify and distribute this software is hereby
* granted provided that (1) source code retains these copyright, permission,
* and disclaimer notices, and (2) redistributions including binaries
* reproduce the notices in supporting documentation, and (3) all advertising
* materials mentioning features or use of this software display the following
* acknowledgement: ``This product includes software developed by the
* Computer Systems Laboratory at the University of Utah.''
*
* THE UNIVERSITY OF UTAH AND CSL ALLOW FREE USE OF THIS SOFTWARE IN ITS "AS
* IS" CONDITION. THE UNIVERSITY OF UTAH AND CSL DISCLAIM ANY LIABILITY OF
* ANY KIND FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
*
* CSL requests users of this software to return to csl-dist@cs.utah.edu any
* improvements that they make and grant CSL redistribution rights.
*/
/*
* Alternate version of memalign
* that expects the caller to keep track of the size of allocated chunks.
* This version is _much_ more memory-efficient
* when allocating many chunks naturally aligned to their (natural) size
* (e.g. allocating naturally-aligned pages or superpages),
* because normal memalign requires a prefix between each chunk
* which will create horrendous fragmentation and memory loss.
* Chunks allocated with this function must be freed with sfree().
*/
#include <stddef.h>
#include "malloc_internal.h"
void *_smemalign(size_t alignment, size_t size)
{
unsigned shift;
void *chunk;
/* Find the alignment shift in bits. XXX use proc_ops.h */
for (shift = 0; (1 << shift) < alignment; shift++);
/*
* Allocate a chunk of LMM memory with the specified alignment shift
* and an offset such that the memory block we return will be aligned.
*/
malloc_lmm_begin();
chunk = lmm_alloc_aligned(&malloc_lmm, size, 0, shift, 0);
malloc_lmm_end();
return chunk;
}
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