Re: [RFC][patch 2/5] mm: Node-setup agnostic free_bootmem()

[Johannes Weiner <hannes@saeurebad.de>]

Hi,

"Yinghai Lu" <yhlu.kernel@gmail.com> writes:

> On Wed, Apr 16, 2008 at 4:36 AM, Johannes Weiner <hannes@saeurebad.de> wrote:
>> Make free_bootmem() look up the node holding the specified address
>>  range which lets it work transparently on single-node and multi-node
>>  configurations.
>>
>>  If the address range exceeds the node range, it well be marked free
>>  across node boundaries, too.
>>
>>  Signed-off-by: Johannes Weiner <hannes@saeurebad.de>
>>  CC: Ingo Molnar <mingo@elte.hu>
>>  CC: Andi Kleen <andi@firstfloor.org>
>>  CC: Yinghai Lu <yhlu.kernel@gmail.com>
>>  CC: Yasunori Goto <y-goto@jp.fujitsu.com>
>>  CC: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
>>  CC: Christoph Lameter <clameter@sgi.com>
>>  CC: Andrew Morton <akpm@linux-foundation.org>
>>  ---
>>   mm/bootmem.c |   10 +++++++++-
>>   1 files changed, 9 insertions(+), 1 deletions(-)
>>
>>  Index: tree-linus/mm/bootmem.c
>>  ===================================================================
>>  --- tree-linus.orig/mm/bootmem.c
>>  +++ tree-linus/mm/bootmem.c
>>  @@ -421,7 +421,32 @@ int __init reserve_bootmem(unsigned long
>>
>>   void __init free_bootmem(unsigned long addr, unsigned long size)
>>   {
>>  -       free_bootmem_core(NODE_DATA(0)->bdata, addr, size);
>>  +       bootmem_data_t *bdata;
>>  +       unsigned long pos = addr;
>>  +       unsigned long partsize = size;
>>  +
>>  +       list_for_each_entry(bdata, &bdata_list, list) {
>>  +               unsigned long remainder = 0;
>>  +
>>  +               if (pos < bdata->node_boot_start)
>>  +                       continue;
>>  +
>>  +               if (PFN_DOWN(pos + partsize) > bdata->node_low_pfn) {
>>  +                       remainder = PFN_DOWN(pos + partsize) - bdata->node_low_pfn;
>>  +                       partsize -= remainder;
>>  +               }
>>  +
>>  +               free_bootmem_core(bdata, pos, partsize);
>>  +
>>  +               if (!remainder)
>>  +                       return;
>>  +
>>  +               pos = PFN_PHYS(bdata->node_low_pfn + 1);
>>  +       }
>>  +       printk(KERN_ERR "free_bootmem: request: addr=%lx, size=%lx, "
>>  +                       "state: pos=%lx, partsize=%lx\n", addr, size,
>>  +                       pos, partsize);
>>  +       BUG();
>>   }
>>
>>   unsigned long __init free_all_bootmem(void)
>>
>>  --
>
> Yes, it should work well with cross nodes case.
>
> but please add boundary check on free_bootmem_node too.

Alright, I will.

	Hannes

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