[PATCH v9 16/18] arm, arm64: do not always merge biovec if we are running on Xen

Olof Johansson olof at lixom.net
Wed Nov 6 10:27:28 EST 2013


On Wed, Nov 6, 2013 at 4:40 AM, Stefano Stabellini
<stefano.stabellini at eu.citrix.com> wrote:
> On Tue, 5 Nov 2013, Olof Johansson wrote:
>> Hi,
>>
>> On Fri, Oct 25, 2013 at 3:51 AM, Stefano Stabellini
>> <stefano.stabellini at eu.citrix.com> wrote:
>> > This is similar to what it is done on X86: biovecs are prevented from merging
>> > otherwise every dma requests would be forced to bounce on the swiotlb buffer.
>> >
>> > Signed-off-by: Stefano Stabellini <stefano.stabellini at eu.citrix.com>
>> > Acked-by: Catalin Marinas <catalin.marinas at arm.com>
>>
>>
>> This is spewing 800+ warnings on ape6evm_defconfig on ARM that doesn't
>> have CONFIG_BLOCK enabled, since struct bio_vec is protected by that
>> in include/linux/blk_types.h. I guess it could be argued that those
>> ifdefs could be removed, but still:
>>
>> ../../arch/arm/include/asm/io.h:378:24: warning: its scope is only
>> this definition or declaration, which is probably not what you want
>> [enabled by default]
>> In file included from ../../include/linux/scatterlist.h:10:0,
>>                  from ../../include/linux/dmaengine.h:27,
>>                  from ../../include/linux/skbuff.h:31,
>>                  from ../../include/crypto/algapi.h:18,
>>                  from ../../crypto/internal.h:16,
>>                  from ../../crypto/cipher.c:21:
>> ../../arch/arm/include/asm/io.h:378:24: warning: 'struct bio_vec'
>> declared inside parameter list [enabled by default]
>>            const struct bio_vec *vec2);
>
> Thanks for letting me know.
> What about the following?
>
>
> commit 06fc174ce8da30f81b59c9d1d7680a2490525884
> Author: Stefano Stabellini <stefano.stabellini at eu.citrix.com>
> Date:   Wed Nov 6 12:38:28 2013 +0000
>
>     arm,arm64/include/asm/io.h: define struct bio_vec
>
>     Signed-off-by: Stefano Stabellini <stefano.stabellini at eu.citrix.com>

Acked-by: Olof Johansson <olof at lixom.net>


-Olof



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