Re: [v6 15/15] mm: debug for raw alloctor

Michal Hocko
2017-08-11T13:08:36Z

On Mon 07-08-17 16:38:49, Pavel Tatashin wrote:
> When CONFIG_DEBUG_VM is enabled, this patch sets all the memory that is
> returned by memblock_virt_alloc_try_nid_raw() to ones to ensure that no
> places excpect zeroed memory.

Please fold this into the patch which introduces
memblock_virt_alloc_try_nid_raw. I am not sure CONFIG_DEBUG_VM is the
best config because that tends to be enabled quite often. Maybe
CONFIG_MEMBLOCK_DEBUG? Or even make it kernel command line parameter?

> Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>
> Reviewed-by: Steven Sistare <steven.sistare@oracle.com>
> Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com>
> Reviewed-by: Bob Picco <bob.picco@oracle.com>
> ---
> mm/memblock.c | 11 +++++++++--
> 1 file changed, 9 insertions(+), 2 deletions(-)
>
> diff --git a/mm/memblock.c b/mm/memblock.c
> index 3fbf3bcb52d9..29fcb1dd8a81 100644
> --- a/mm/memblock.c
> +++ b/mm/memblock.c
> @@ -1363,12 +1363,19 @@ void * __init memblock_virt_alloc_try_nid_raw(
> phys_addr_t min_addr, phys_addr_t max_addr,
> int nid)
> {
> + void *ptr;
> +
> memblock_dbg("%s: %llu bytes align=0x%llx nid=%d from=0x%llx max_addr=0x%llx %pF\n",
> __func__, (u64)size, (u64)align, nid, (u64)min_addr,
> (u64)max_addr, (void *)_RET_IP_);
>
> - return memblock_virt_alloc_internal(size, align,
> - min_addr, max_addr, nid);
> + ptr = memblock_virt_alloc_internal(size, align,
> + min_addr, max_addr, nid);
> +#ifdef CONFIG_DEBUG_VM
> + if (ptr && size > 0)
> + memset(ptr, 0xff, size);
> +#endif
> + return ptr;
> }
>
> /**
> --
> 2.14.0

--
Michal Hocko
SUSE Labs