Re: [PATCH 5/9] treewide: use kv[mz]alloc* rather than opencoded variants

[Vlastimil Babka]

On 01/30/2017 10:49 AM, Michal Hocko wrote:
> From: Michal Hocko <mhocko@xxxxxxxx>
>
> There are many code paths opencoding kvmalloc. Let's use the helper
> instead. The main difference to kvmalloc is that those users are usually
> not considering all the aspects of the memory allocator. E.g. allocation
> requests <= 32kB (with 4kB pages) are basically never failing and invoke
> OOM killer to satisfy the allocation. This sounds too disruptive for
> something that has a reasonable fallback - the vmalloc. On the other
> hand those requests might fallback to vmalloc even when the memory
> allocator would succeed after several more reclaim/compaction attempts
> previously. There is no guarantee something like that happens though.
>
> This patch converts many of those places to kv[mz]alloc* helpers because
> they are more conservative.
>
> Changes since v1
> - add kvmalloc_array - this might silently fix some overflow issues
>   because most users simply didn't check the overflow for the vmalloc
>   fallback.
>
> Cc: Martin Schwidefsky <schwidefsky@xxxxxxxxxx>
> Cc: Heiko Carstens <heiko.carstens@xxxxxxxxxx>
> Cc: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
> Cc: Anton Vorontsov <anton@xxxxxxxxxx>
> Cc: Colin Cross <ccross@xxxxxxxxxxx>
> Cc: Kees Cook <keescook@xxxxxxxxxxxx>
> Cc: Tony Luck <tony.luck@xxxxxxxxx>
> Cc: "Rafael J. Wysocki" <rjw@xxxxxxxxxxxxx>
> Cc: Ben Skeggs <bskeggs@xxxxxxxxxx>
> Cc: Kent Overstreet <kent.overstreet@xxxxxxxxx>
> Cc: Santosh Raspatur <santosh@xxxxxxxxxxx>
> Cc: Hariprasad S <hariprasad@xxxxxxxxxxx>
> Cc: Yishai Hadas <yishaih@xxxxxxxxxxxx>
> Cc: Oleg Drokin <oleg.drokin@xxxxxxxxx>
> Cc: "Yan, Zheng" <zyan@xxxxxxxxxx>
> Cc: Alexander Viro <viro@xxxxxxxxxxxxxxxxxx>
> Cc: Alexei Starovoitov <ast@xxxxxxxxxx>
> Cc: Eric Dumazet <eric.dumazet@xxxxxxxxx>
> Cc: netdev@xxxxxxxxxxxxxxx
> Acked-by: Andreas Dilger <andreas.dilger@xxxxxxxxx> # Lustre
> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx> # Xen bits
> Acked-by: Christian Borntraeger <borntraeger@xxxxxxxxxx> # KVM/s390
> Acked-by: Dan Williams <dan.j.williams@xxxxxxxxx> # nvdim
> Acked-by: David Sterba <dsterba@xxxxxxxx> # btrfs
> Acked-by: Ilya Dryomov <idryomov@xxxxxxxxx> # Ceph
> Acked-by: Tariq Toukan <tariqt@xxxxxxxxxxxx> # mlx4
> Signed-off-by: Michal Hocko <mhocko@xxxxxxxx>

Acked-by: Vlastimil Babka <vbabka@xxxxxxx>