Subject: Re: [PATCH V2] net: ethernet: mellanox: correct page conversion
To: eranlinuxmellanox@gmail.com
References: <1460845412-13120-1-git-send-email-okaya@codeaurora.org>
 <20160419182212.GA8441@infradead.org> <571785A5.5040306@codeaurora.org>
Cc: Christoph Hellwig <hch@infradead.org>, linux-rdma@vger.kernel.org,
        timur@codeaurora.org, cov@codeaurora.org,
        Yishai Hadas <yishaih@mellanox.com>, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org
From: Sinan Kaya <okaya@codeaurora.org>
Message-ID: <57178663.4050503@codeaurora.org>
Date: Wed, 20 Apr 2016 09:38:43 -0400
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Apologies,

Replied to an older post by mistake. I was trying to reply to Eran.

>Hi Sinan,
>
>We are working in Mellanox for a solution which
>removes the vmap call and allocate contiguous memory (using dma_alloc_coherent).
>
>Thanks,
>Eran
>
>
>On 4/20/2016 9:35 AM, Sinan Kaya wrote:
> On 4/19/2016 2:22 PM, Christoph Hellwig wrote:
>> What I think we need is something like the patch below.  In the long
>> ru nwe should also kill the mlx4_buf structure which now is pretty
>> pointless.
>>
> 

It is been 1.5 years since I reported the problem. We came up with three
different solutions this week. I'd like to see a version of the solution
to get merged until Mellanox comes up with a better solution with another
patch. My proposal is to use this one.

> 
> -- a/drivers/net/ethernet/mellanox/mlx4/alloc.c
> +++ b/drivers/net/ethernet/mellanox/mlx4/alloc.c
> @@ -588,7 +588,7 @@ int mlx4_buf_alloc(struct mlx4_dev *dev, int size, int max_direct,
>  {
>         dma_addr_t t;
> 
> -       if (size <= max_direct) {
> +       if ((size <= max_direct) || (BITS_PER_LONG == 64)){
>                 buf->nbufs        = 1;
>                 buf->npages       = 1;
>                 buf->page_shift   = get_order(size) + PAGE_SHIFT;
> 
> Of course, this is assuming that you are not ready to submit your patch yet. If you 
> are, feel free to post.
> 


-- 
Sinan Kaya
Qualcomm Technologies, Inc. on behalf of Qualcomm Innovation Center, Inc.
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project