Re: [Drbd-dev] [PATCH v4 0/8] block: prepare for multipage bvecs

Re: [Drbd-dev] [PATCH v4 0/8] block: prepare for multipage bvecs

[Jens Axboe]

On 04/14/2016 05:46 AM, Ming Lei wrote:
> Hi,
>
> Interests[1] have been shown in multipage bvecs, so this patchset
> try to prepare for the support and do two things:
>
> 1) the 1st 4 patches use bvec iterator to implement iterate_bvec(),
> then we can drop the non-standard way for iterating bvec, which
> can be thought as a good cleanup for lib/iov_iter.c
>
> 2) remove BIO_MAX_SECTORS & BIO_MAX_SIZE, and now there is only
> one user for each. Once multipage bvecs is introduced, one bio
> may hold lots of sectors, and we should always use sort of BIO_MAX_VECS
> which should be introduced in future and is similiar with current
> BIO_MAX_PAGES.
>
> xfstests(-a auto) have been run over ext4/xfs and no regression found
> by this patchset.

We've had too many disasters in the block layer the last few series, I'm 
making the 4.7 round a nice and small one. I don't mind taking prep 
patches for the multipage bvecs, if they are simple and clean, but 
that's about the extent of it.

Just a heads up.

-- 
Jens Axboe

Re: [Drbd-dev] [PATCH v4 0/8] block: prepare for multipage bvecs

[Ming Lei]

On Thu, Apr 14, 2016 at 10:11 PM, Jens Axboe <axboe@kernel.dk> wrote:
> On 04/14/2016 05:46 AM, Ming Lei wrote:
>>
>> Hi,
>>
>> Interests[1] have been shown in multipage bvecs, so this patchset
>> try to prepare for the support and do two things:
>>
>> 1) the 1st 4 patches use bvec iterator to implement iterate_bvec(),
>> then we can drop the non-standard way for iterating bvec, which
>> can be thought as a good cleanup for lib/iov_iter.c
>>
>> 2) remove BIO_MAX_SECTORS & BIO_MAX_SIZE, and now there is only
>> one user for each. Once multipage bvecs is introduced, one bio
>> may hold lots of sectors, and we should always use sort of BIO_MAX_VECS
>> which should be introduced in future and is similiar with current
>> BIO_MAX_PAGES.
>>
>> xfstests(-a auto) have been run over ext4/xfs and no regression found
>> by this patchset.
>
>
> We've had too many disasters in the block layer the last few series, I'm
> making the 4.7 round a nice and small one. I don't mind taking prep patches
> for the multipage bvecs, if they are simple and clean, but that's about the
> extent of it.
>
> Just a heads up.

Jens, thanks for your response, and understood your concerns.

Please hold on this patchset, and I will check it further and make it
better.

Thanks,