Re: [BLOCK] phys_contig implies hw_contig

From: Herbert Xu
Date: Sat Nov 01 2003 - 23:48:47 EST

On Sat, Nov 01, 2003 at 08:45:47PM -0800, David S. Miller wrote:
> On Sat, 1 Nov 2003 13:31:27 +1100
> Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx> wrote:
> > In ll_merge_requests_fn, it is checking blk_hw_contig_segments even if
> > blk_phys_contig_segments succeeds. This means that it may cause two
> > physically contiguous segments to be separated because the hw check
> > fails.
> Your analysis assumes that phys contig implies hw contig, I
> believe it does not. There may be limitations in the VMERGE
> mechanism a platform implements that causes this situation to
> arise.

OK, if that's the case, then we better change blk_recount_segments
as it assumes this.

Debian GNU/Linux 3.0 is out! ( )
Email: Herbert Xu ~{PmV>HI~} <herbert@xxxxxxxxxxxxxxxxxxx>
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