Re: [PATCH 1/2] videobuf2-dma-sg: Allocate pages as contiguous as possible

2013-08-02 Thread Marek Szyprowski
Hello, On 7/19/2013 7:02 PM, Ricardo Ribalda Delgado wrote: Most DMA engines have limitations regarding the number of DMA segments (sg-buffers) that they can handle. Videobuffers can easily spread through houndreds of pages. In the previous aproach, the pages were allocated individually, this

Re: [PATCH 1/2] videobuf2-dma-sg: Allocate pages as contiguous as possible

2013-08-02 Thread Andre Heider
Hi Ricardo, sorry for the late answer, but the leak I mentioned in my first reply is still there, see below. On Fri, Jul 19, 2013 at 07:02:33PM +0200, Ricardo Ribalda Delgado wrote: Most DMA engines have limitations regarding the number of DMA segments (sg-buffers) that they can handle.

Re: [PATCH 1/2] videobuf2-dma-sg: Allocate pages as contiguous as possible

2013-08-02 Thread Ricardo Ribalda Delgado
Hi Andre, Nice catch! thanks. I have just uploaded a new version. https://patchwork.linuxtv.org/patch/19502/ https://patchwork.linuxtv.org/patch/19503/ Thanks for your help On Fri, Aug 2, 2013 at 10:46 AM, Andre Heider a.hei...@gmail.com wrote: Hi Ricardo, sorry for the late answer, but

Re: [PATCH 1/2] videobuf2-dma-sg: Allocate pages as contiguous as possible

2013-08-02 Thread Andre Heider
Hi Ricardo, I messed up one thing in my initial reply, sorry :( And two additional nitpicks, while we're at it. On Fri, Jul 19, 2013 at 07:02:33PM +0200, Ricardo Ribalda Delgado wrote: Most DMA engines have limitations regarding the number of DMA segments (sg-buffers) that they can handle.

Re: [PATCH 1/2] videobuf2-dma-sg: Allocate pages as contiguous as possible

2013-08-02 Thread Ricardo Ribalda Delgado
Thanks, I have just send a new version. Regards! On Fri, Aug 2, 2013 at 3:47 PM, Andre Heider a.hei...@gmail.com wrote: Hi Ricardo, I messed up one thing in my initial reply, sorry :( And two additional nitpicks, while we're at it. On Fri, Jul 19, 2013 at 07:02:33PM +0200, Ricardo Ribalda

Re: [PATCH 1/2] videobuf2-dma-sg: Allocate pages as contiguous as possible

2013-08-01 Thread Ricardo Ribalda Delgado
Hi Sakarius I think the whole point of the videobuf2 is sharing pages with the user space, so until vm_insert_page does not support high order pages we should split them. Unfortunately the mm is completely out of my topic, so I don't think that I could be very useful there. With my patch, in the

Re: [PATCH 1/2] videobuf2-dma-sg: Allocate pages as contiguous as possible

2013-07-31 Thread Sakari Ailus
Hi Jon and Sylwester, On Mon, Jul 29, 2013 at 09:16:44AM -0600, Jonathan Corbet wrote: On Mon, 29 Jul 2013 13:27:12 +0200 Marek Szyprowski m.szyprow...@samsung.com wrote: You've gone to all this trouble to get a higher-order allocation so you'd have fewer segments, then you undo it all

Re: [PATCH 1/2] videobuf2-dma-sg: Allocate pages as contiguous as possible

2013-07-29 Thread Marek Szyprowski
Hello, On 7/19/2013 10:16 PM, Jonathan Corbet wrote: On Fri, 19 Jul 2013 19:02:33 +0200 Ricardo Ribalda Delgado ricardo.riba...@gmail.com wrote: Most DMA engines have limitations regarding the number of DMA segments (sg-buffers) that they can handle. Videobuffers can easily spread through

Re: [PATCH 1/2] videobuf2-dma-sg: Allocate pages as contiguous as possible

2013-07-29 Thread Jonathan Corbet
On Mon, 29 Jul 2013 13:27:12 +0200 Marek Szyprowski m.szyprow...@samsung.com wrote: You've gone to all this trouble to get a higher-order allocation so you'd have fewer segments, then you undo it all by splitting things apart into individual pages. Why? Clearly I'm missing something, this

Re: [PATCH 1/2] videobuf2-dma-sg: Allocate pages as contiguous as possible

2013-07-19 Thread Jonathan Corbet
On Fri, 19 Jul 2013 19:02:33 +0200 Ricardo Ribalda Delgado ricardo.riba...@gmail.com wrote: Most DMA engines have limitations regarding the number of DMA segments (sg-buffers) that they can handle. Videobuffers can easily spread through houndreds of pages. In the previous aproach, the pages

Re: [PATCH 1/2] videobuf2-dma-sg: Allocate pages as contiguous as possible

2013-07-19 Thread Ricardo Ribalda Delgado
Hello Jonathan: Thanks for your review. I am making a driver for a camera that produces 4Mpx images with up to 10 bytes per pixel!. The camera has a dma engine capable of moving up to 255 sg sectors. In the original implementation of vb2-dma-sg, every page was allocated independently, dividing