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Date:   Mon, 28 Oct 2019 09:37:32 -0700
From:   Sultan Alsawaf <sultan@kerneltoast.com>
To:     Christoph Hellwig <hch@infradead.org>
Cc:     Jason Gunthorpe <jgg@ziepe.ca>,
        "Martin K. Petersen" <martin.petersen@oracle.com>,
        Thomas Hellstrom <thellstrom@vmware.com>,
        Palmer Dabbelt <palmer@sifive.com>,
        Sakari Ailus <sakari.ailus@linux.intel.com>,
        Ming Lei <ming.lei@redhat.com>,
        Gal Pressman <galpress@amazon.com>,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH] scatterlist: Speed up for_each_sg() loop macro
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On Mon, Oct 28, 2019 at 09:28:16AM -0700, Christoph Hellwig wrote:
> And there is nothing forcing a particular layout, there just happens
> to be a layout that the generic allocator gives you.  I'm not even
> sure the original patch handles the SCSI case of small inlines segments
> properly.

I'm doubtful; are there really sg users that craft their own sglists and then
use for_each_sg() on them? But like I mentioned in the email I sent a
few minutes ago, this can be alleviated with a more comprehensive version of
this patch that alters all for_each_sg() users and thus ensures that only
sg_table pointers can be used with the macro. Anyone who would munge their own
sg_table together would simply be insane :)

Or there could be a separate macro for iterating through each sg in an sg_table.
There are lots of ways to go about this.

Sultan