On Tue, Jan 08, 2013 at 07:31:30AM -0700, Jonathan Corbet wrote:
> On Tue, 08 Jan 2013 07:50:41 +0100
> Marek Szyprowski wrote:
>
> > > Couldn't this performance difference be due to the usage of GFP_DMA inside
> > > the VB2 code, like Federico's new patch series is proposing?
> > >
> > > If not,
On Tue, 08 Jan 2013 07:50:41 +0100
Marek Szyprowski wrote:
> > Couldn't this performance difference be due to the usage of GFP_DMA inside
> > the VB2 code, like Federico's new patch series is proposing?
> >
> > If not, why are there a so large performance penalty?
>
> Nope, this was caused rat
On 1/7/2013 9:15 PM, Mauro Carvalho Chehab wrote:
Em Mon, 7 Jan 2013 12:40:50 -0700
Jonathan Corbet escreveu:
> On Mon, 7 Jan 2013 00:09:47 +0100
> Alessandro Rubini wrote:
>
> > I don't expect you'll see serious performance differences on the PC. I
> > think ARM users will have better benefi
Em Mon, 7 Jan 2013 12:40:50 -0700
Jonathan Corbet escreveu:
> On Mon, 7 Jan 2013 00:09:47 +0100
> Alessandro Rubini wrote:
>
> > I don't expect you'll see serious performance differences on the PC. I
> > think ARM users will have better benefits, due to the different cache
> > architecture. Yo
On Mon, 7 Jan 2013 00:09:47 +0100
Alessandro Rubini wrote:
> I don't expect you'll see serious performance differences on the PC. I
> think ARM users will have better benefits, due to the different cache
> architecture. You told me Jon measured meaningful figures on a Marvel
> CPU.
It made the
> The problem is that on the sta2x11 architecture only the first
> 512MB are available through the PCI bus, but the allocator can allocate
> memory
> for DMA above this limit. By using GFP_DMA flags the allocation take place
> under the 16MB so it works.
Still, you are not running the upstream
> I have more information about DMA on the board that I'm using; probably, I
> can make dma-contig work with my device.
Ok, the driver STA2X11 now works with a patched dma-contig allocator. So, my
streaming allocator it is not mandatory.
I based my work on the previous work made by Windriver, b
On Thursday 03 January 2013 17:13:14 Federico Vaga wrote:
> > After all those discussions, I'm ok on adding this new driver, but please
> > add a summary of those discussions at the patch description. As I said,
> > the reason why this driver is needed is not obvious. So, it needs to be
> > very we
> After all those discussions, I'm ok on adding this new driver, but please
> add a summary of those discussions at the patch description. As I said,
> the reason why this driver is needed is not obvious. So, it needs to be
> very well described.
ack. I will ask more information to ST about the bo
Hi Federico,
Em Thu, 20 Dec 2012 16:37:50 +0100
Federico Vaga escreveu:
> > I can take a look at the dma coherent issues with that board, but I
> will
> > need some help as I don't have this hardware.
>
> I have the hardware, but I don't have the full knowledge of the
> boards. As I told befo
> I can take a look at the dma coherent issues with that board, but I
will
> need some help as I don't have this hardware.
I have the hardware, but I don't have the full knowledge of the
boards. As I told before, I asked to windriver which develop the
software for the whole board, but they cann
Hello,
I'm sorry for the delay, I've been terribly busy recently.
On 12/11/2012 2:54 PM, Federico Vaga wrote:
> This allocator is needed because some device (like STA2X11 VIP) cannot
> work
> with DMA sg or DMA coherent. Some other device (like the one used by
> Jonathan when he proposes vb2-d
Sorry for the late answer to this.
> > This allocator is needed because some device (like STA2X11 VIP) cannot
> > work
> > with DMA sg or DMA coherent. Some other device (like the one used by
> > Jonathan when he proposes vb2-dma-nc allocator) can obtain much better
> > performance with DMA stream
Em 05-12-2012 10:50, Federico Vaga escreveu:
On Tuesday 04 December 2012 14:04:22 Mauro Carvalho Chehab wrote:
Em 24-09-2012 09:44, Marek Szyprowski escreveu:
Hello,
On Monday, September 24, 2012 12:59 PM Federico Vaga wrote:
The DMA streaming allocator is similar to the DMA contig but it use
On Tuesday 04 December 2012 14:04:22 Mauro Carvalho Chehab wrote:
> Em 24-09-2012 09:44, Marek Szyprowski escreveu:
> > Hello,
> >
> > On Monday, September 24, 2012 12:59 PM Federico Vaga wrote:
> >> The DMA streaming allocator is similar to the DMA contig but it use the
> >> DMA streaming interfa
Em 24-09-2012 09:44, Marek Szyprowski escreveu:
Hello,
On Monday, September 24, 2012 12:59 PM Federico Vaga wrote:
The DMA streaming allocator is similar to the DMA contig but it use the
DMA streaming interface (dma_map_single, dma_unmap_single). The
allocator allocates buffers and immediately
Hello,
On Monday, September 24, 2012 12:59 PM Federico Vaga wrote:
> The DMA streaming allocator is similar to the DMA contig but it use the
> DMA streaming interface (dma_map_single, dma_unmap_single). The
> allocator allocates buffers and immediately map the memory for DMA
> transfer. For each
The DMA streaming allocator is similar to the DMA contig but it use the
DMA streaming interface (dma_map_single, dma_unmap_single). The
allocator allocates buffers and immediately map the memory for DMA
transfer. For each buffer prepare/finish it does a DMA synchronization.
Signed-off-by: Federico
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