[..] > +/* > + * If flags is 0, then the return value is always 0 (success). If > + * flags contains BOOTMEM_EXCLUSIVE, then -EBUSY is returned if the > + * memory already was reserved. > + */ > +extern int reserve_bootmem(unsigned long addr, unsigned long size, int flags); > #define alloc_bootmem(x) \ > __alloc_bootmem(x, SMP_CACHE_BYTES, __pa(MAX_DMA_ADDRESS)) > #define alloc_bootmem_low(x) \ > --- a/mm/bootmem.c > +++ b/mm/bootmem.c > @@ -111,8 +111,8 @@ static unsigned long __init init_bootmem > * might be used for boot-time allocations - or it might get added > * to the free page pool later on. > */ > -static void __init reserve_bootmem_core(bootmem_data_t *bdata, unsigned long addr, > - unsigned long size) > +static int __init reserve_bootmem_core(bootmem_data_t *bdata, unsigned long addr, > + unsigned long size, int flags) > { > unsigned long sidx, eidx; > unsigned long i; > @@ -133,7 +133,11 @@ static void __init reserve_bootmem_core( > #ifdef CONFIG_DEBUG_BOOTMEM > printk("hm, page %08lx reserved twice.\n", i*PAGE_SIZE); > #endif > + if (flags & BOOTMEM_EXCLUSIVE) > + return -EBUSY; I think we should unreserve the chunks of memory we have reserved so far (Memory reserved from sidx to i), in case of error. Thanks Vivek