Messages in this thread | | | Date | Fri, 29 May 2015 11:15:35 -0400 | From | Mike Snitzer <> | Subject | Re: [PATCH v4 01/11] block: make generic_make_request handle arbitrarily sized bios |
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On Fri, May 29 2015 at 3:05P -0400, Ming Lin <mlin@kernel.org> wrote:
> On Wed, May 27, 2015 at 5:36 PM, Alasdair G Kergon <agk@redhat.com> wrote: > > On Wed, May 27, 2015 at 04:42:44PM -0700, Ming Lin wrote: > >> Here are fio results of XFS on a DM stripped target with 2 SSDs + 1 HDD. > >> Does it make sense? > > > > To stripe across devices with different characteristics? > > > > Some suggestions. > > > > Prepare 3 kernels. > > O - Old kernel. > > M - Old kernel with merge_bvec_fn disabled. > > How to disable it? > Maybe just hack it as below? > > void blk_queue_merge_bvec(struct request_queue *q, merge_bvec_fn *mbfn) > { > //q->merge_bvec_fn = mbfn; > }
Right, there isn't an existing way to disable it, you'd need a hack like that.
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