From: Jason Gunthorpe <jgg@nvidia.com>
To: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Cc: Maor Gottlieb <maorg@nvidia.com>, Christoph Hellwig <hch@lst.de>,
"Gal Pressman" <galpress@amazon.com>,
Bob Pearson <rpearsonhpe@gmail.com>,
"Leon Romanovsky" <leonro@nvidia.com>,
<linux-rdma@vger.kernel.org>
Subject: Re: dynamic-sg patch has broken rdma_rxe
Date: Tue, 20 Oct 2020 08:47:10 -0300 [thread overview]
Message-ID: <20201020114710.GC6219@nvidia.com> (raw)
In-Reply-To: <03541c89-92d0-2dc8-5e40-03f3fe527fef@linux.intel.com>
On Tue, Oct 20, 2020 at 12:37:05PM +0100, Tvrtko Ursulin wrote:
> > Why put this confusing code in every caller? Especially for something
> > a driver is supposed to call. Will just make bugs
>
> For max_segment to be aligned is a requirement today so callers are
> ready.
No, it turns out all the RDMA drivers were became broken when they
converted to use the proper U32_MAX for their DMA max_segment size,
then they couldn't form SGLs anymore.
I don't want to see nonsense code like this:
dma_set_max_seg_size(dev->dev, min_t(unsigned int, U32_MAX & PAGE_MASK,
SCATTERLIST_MAX_SEGMENT));
In drivers.
dma_set_max_seg_size is the *hardware* capability, and mixing in
things like PAG_MASK here is just nonsense.
Jason
next prev parent reply other threads:[~2020-10-20 11:47 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-13 14:33 dynamic-sg patch has broken rdma_rxe Bob Pearson
2020-10-13 16:34 ` Bob Pearson
2020-10-14 22:51 ` Jason Gunthorpe
2020-10-15 7:44 ` Maor Gottlieb
2020-10-15 11:23 ` Gal Pressman
2020-10-15 12:21 ` Maor Gottlieb
2020-10-16 0:31 ` Jason Gunthorpe
2020-10-16 7:13 ` Christoph Hellwig
[not found] ` <796ca31aed8f469c957cb850385b9d09@intel.com>
2020-10-16 11:58 ` Jason Gunthorpe
2020-10-19 9:50 ` Tvrtko Ursulin
2020-10-19 12:12 ` Jason Gunthorpe
2020-10-19 12:29 ` Tvrtko Ursulin
2020-10-19 12:48 ` Jason Gunthorpe
2020-10-20 11:37 ` Tvrtko Ursulin
2020-10-20 11:47 ` Jason Gunthorpe [this message]
2020-10-20 12:31 ` Tvrtko Ursulin
2020-10-20 12:56 ` Jason Gunthorpe
2020-10-20 13:09 ` Tvrtko Ursulin
2020-10-20 13:32 ` Jason Gunthorpe
2020-10-15 15:35 ` Bob Pearson
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