From: Andrew Morton <akpm@linux-foundation.org>
To: Jens Axboe <jens.axboe@oracle.com>
Cc: linux-kernel@vger.kernel.org
Subject: Re: [PATCH 7/13] i386 sg: add support for chaining scatterlists
Date: Thu, 10 May 2007 03:52:07 -0700 [thread overview]
Message-ID: <20070510035207.37a528ae.akpm@linux-foundation.org> (raw)
In-Reply-To: <20070510104653.GM4629@kernel.dk>
On Thu, 10 May 2007 12:46:53 +0200 Jens Axboe <jens.axboe@oracle.com> wrote:
> On Thu, May 10 2007, Jens Axboe wrote:
> > Yeah, I'm inclined to agree. Perhaps it would be better to put this
> > stuff in lib/scatterlist.c or something like that instead?
> >
> > > > +/*
> > > > + * Chain previous sglist to this one
> > > > + */
> > > > +static inline void sg_chain(struct scatterlist *prv, unsigned int prv_nents,
> > > > + struct scatterlist *sgl)
> > > > +{
> > > > +#ifndef ARCH_HAS_SG_CHAIN
> > > > + BUG();
> > > > +#endif
> > >
> > > Can use BUILD_BUG_ON here. Or just #error.
> >
> > Good idea, thanks!
>
> No wait a second, that wont work. The code is always being built in sg
> scsi_lib.c, it should just not be called unless we can do chaining. We
> will never have a large number of segments that require chaining without
> ARCH_HAS_SG_CHAIN, so it'll never be called in that case. So it has to
> remain as it is, a BUG().
Confused. If it should never be called, why does it even get compiled in?
next prev parent reply other threads:[~2007-05-10 10:52 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-05-10 10:21 [PATCH 0/13] Chaining sg lists for bio IO commands v3 Jens Axboe
2007-05-10 10:21 ` [PATCH 1/13] crypto: don't pollute the global namespace with sg_next() Jens Axboe
2007-05-10 10:21 ` [PATCH 2/13] Add sg helpers for iterating over a scatterlist table Jens Axboe
2007-05-10 10:39 ` Andrew Morton
2007-05-10 10:42 ` Jens Axboe
2007-05-10 10:21 ` [PATCH 3/13] libata: convert to using sg helpers Jens Axboe
2007-05-10 10:21 ` [PATCH 4/13] block: " Jens Axboe
2007-05-10 10:21 ` [PATCH 5/13] scsi: " Jens Axboe
2007-05-10 10:21 ` [PATCH 6/13] i386 dma_map_sg: " Jens Axboe
2007-05-10 10:21 ` [PATCH 7/13] i386 sg: add support for chaining scatterlists Jens Axboe
2007-05-10 10:43 ` Andrew Morton
2007-05-10 10:44 ` Jens Axboe
2007-05-10 10:46 ` Jens Axboe
2007-05-10 10:52 ` Andrew Morton [this message]
2007-05-10 11:21 ` Jens Axboe
2007-05-10 10:59 ` Benny Halevy
2007-05-10 11:23 ` Jens Axboe
2007-05-10 10:21 ` [PATCH 8/13] x86-64: update iommu/dma mapping functions to sg helpers Jens Axboe
2007-05-10 10:21 ` [PATCH 9/13] [PATCH] x86-64: enable sg chaining Jens Axboe
2007-05-10 10:21 ` [PATCH 10/13] scsi: simplify scsi_free_sgtable() Jens Axboe
2007-05-10 10:21 ` [PATCH 11/13] SCSI: support for allocating large scatterlists Jens Axboe
2007-05-10 10:48 ` Andrew Morton
2007-05-10 10:52 ` Jens Axboe
2007-05-10 12:38 ` Alan Cox
2007-05-10 10:21 ` [PATCH 12/13] ll_rw_blk: temporarily enable max_segments tweaking Jens Axboe
2007-05-10 10:49 ` Andrew Morton
2007-05-10 11:20 ` Jens Axboe
2007-05-10 10:21 ` [PATCH 13/13] scsi drivers: sg chaining Jens Axboe
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