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

From: Leon Romanovsky <leon@kernel.org>
To: Michal Hocko <mhocko@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>,
	Vlastimil Babka <vbabka@suse.cz>,
	David Rientjes <rientjes@google.com>,
	Mel Gorman <mgorman@suse.de>,
	Johannes Weiner <hannes@cmpxchg.org>,
	Al Viro <viro@zeniv.linux.org.uk>,
	linux-mm@kvack.org, LKML <linux-kernel@vger.kernel.org>,
	Michal Hocko <mhocko@suse.com>,
	Martin Schwidefsky <schwidefsky@de.ibm.com>,
	Heiko Carstens <heiko.carstens@de.ibm.com>,
	Herbert Xu <herbert@gondor.apana.org.au>,
	Anton Vorontsov <anton@enomsg.org>,
	Colin Cross <ccross@android.com>,
	Kees Cook <keescook@chromium.org>,
	Tony Luck <tony.luck@intel.com>,
	"Rafael J. Wysocki" <rjw@rjwysocki.net>,
	Ben Skeggs <bskeggs@redhat.com>,
	Kent Overstreet <kent.overstreet@gmail.com>,
	Santosh Raspatur <santosh@chelsio.com>,
	Hariprasad S <hariprasad@chelsio.com>,
	Yishai Hadas <yishaih@mellanox.com>,
	Oleg Drokin <oleg.drokin@intel.com>,
	"Yan, Zheng" <zyan@redhat.com>,
	Alexei Starovoitov <ast@kernel.org>,
	Eric Dumazet <eric.dumazet@gmail.com>,
	netdev@vger.kernel.org
Subject: Re: [PATCH 5/9] treewide: use kv[mz]alloc* rather than opencoded variants
Date: Mon, 30 Jan 2017 12:21:55 +0200	[thread overview]
Message-ID: <20170130102155.GK6005@mtr-leonro.local> (raw)
In-Reply-To: <20170130094940.13546-6-mhocko@kernel.org>

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On Mon, Jan 30, 2017 at 10:49:36AM +0100, Michal Hocko wrote:
> From: Michal Hocko <mhocko@suse.com>
>
> 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@de.ibm.com>
> Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
> Cc: Herbert Xu <herbert@gondor.apana.org.au>
> Cc: Anton Vorontsov <anton@enomsg.org>
> Cc: Colin Cross <ccross@android.com>
> Cc: Kees Cook <keescook@chromium.org>
> Cc: Tony Luck <tony.luck@intel.com>
> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
> Cc: Ben Skeggs <bskeggs@redhat.com>
> Cc: Kent Overstreet <kent.overstreet@gmail.com>
> Cc: Santosh Raspatur <santosh@chelsio.com>
> Cc: Hariprasad S <hariprasad@chelsio.com>
> Cc: Yishai Hadas <yishaih@mellanox.com>
> Cc: Oleg Drokin <oleg.drokin@intel.com>
> Cc: "Yan, Zheng" <zyan@redhat.com>
> Cc: Alexander Viro <viro@zeniv.linux.org.uk>
> Cc: Alexei Starovoitov <ast@kernel.org>
> Cc: Eric Dumazet <eric.dumazet@gmail.com>
> Cc: netdev@vger.kernel.org
> Acked-by: Andreas Dilger <andreas.dilger@intel.com> # Lustre
> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> # Xen bits
> Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> # KVM/s390
> Acked-by: Dan Williams <dan.j.williams@intel.com> # nvdim
> Acked-by: David Sterba <dsterba@suse.com> # btrfs
> Acked-by: Ilya Dryomov <idryomov@gmail.com> # Ceph
> Acked-by: Tariq Toukan <tariqt@mellanox.com> # mlx4
> Signed-off-by: Michal Hocko <mhocko@suse.com>

Acked-by: Leon Romanovsky <leonro@mellanox.com> # mlx5

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