Re: [RFC][patch 1/5] mm: Revert "mm: fix boundary checking in free_bootmem_core"

[Yinghai Lu]

On Wed, Apr 16, 2008 at 4:36 AM, Johannes Weiner <hannes@xxxxxxxxxxxx> wrote:
> This reverts commit 5a982cbc7b3fe6cf72266f319286f29963c71b9e.
>
>  The intention behind this patch was to make the free_bootmem()
>  interface more robust with regards to the specified range and to let
>  it operate on multiple node setups as well.
>
>  However, it made free_bootmem_core()
>
>   1. handle bogus node/memory-range combination input by just
>      returning early without informing the callsite or screaming BUG()
>      as it did before
>   2. round slightly out of node-range values to the node boundaries
>      instead of treating them as the invalid parameters they are
>
>  This was partially done to abuse free_bootmem_core() for node
>  iteration in free_bootmem (just feeding it every node on the box and
>  let it figure out what it wants to do with it) instead of looking up
>  the proper node before the call to free_bootmem_core().
>
>  It also affects free_bootmem_node() which relies on
>  free_bootmem_core() and on its sanity checks now removed.
>
>  Signed-off-by: Johannes Weiner <hannes@xxxxxxxxxxxx>
>  CC: Yinghai Lu <yhlu.kernel@xxxxxxxxx>
>  CC: Andi Kleen <andi@xxxxxxxxxxxxxx>
>  CC: Yasunori Goto <y-goto@xxxxxxxxxxxxxx>
>  CC: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
>  CC: Ingo Molnar <mingo@xxxxxxx>
>  CC: Christoph Lameter <clameter@xxxxxxx>
>  CC: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
>  ---
>   mm/bootmem.c |   25 ++++++-------------------
>   1 files changed, 6 insertions(+), 19 deletions(-)
>
>  diff --git a/mm/bootmem.c b/mm/bootmem.c
>  index 2ccea70..f6ff433 100644
>  --- a/mm/bootmem.c
>  +++ b/mm/bootmem.c
>  @@ -125,7 +125,6 @@ static int __init reserve_bootmem_core(bootmem_data_t *bdata,
>         BUG_ON(!size);
>         BUG_ON(PFN_DOWN(addr) >= bdata->node_low_pfn);
>         BUG_ON(PFN_UP(addr + size) > bdata->node_low_pfn);
>  -       BUG_ON(addr < bdata->node_boot_start);
>
>         sidx = PFN_DOWN(addr - bdata->node_boot_start);
>         eidx = PFN_UP(addr + size - bdata->node_boot_start);

can you keep the change with reserve_bootmem_core? another patch
regarding reserve_bootmem will update it further.

YH
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