Re: [BLOCK] phys_contig implies hw_contig

[Herbert Xu]

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.

Cheers,
-- 
Debian GNU/Linux 3.0 is out! ( http://www.debian.org/ )
Email:  Herbert Xu ~{PmV>HI~} <herbert@xxxxxxxxxxxxxxxxxxx>
Home Page: http://gondor.apana.org.au/~herbert/
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