Hi Han, Thank you very much. I will check the link.
Thanks Wen >-----Original Message----- >From: Jonghun Han [mailto:jonghun....@samsung.com] >Sent: 2011年2月9日 15:58 >To: 'Hans Verkuil'; Wang, Wen W; 'Jozef Kruger' >Cc: Kanigeri, Hari K; Iyer, Sundar; Yang, Jianwei; linux-media@vger.kernel.org; >조경호/S/W Solution개발팀(S.LSI)/E4(선임)/삼성전자 >Subject: RE: Memory allocation in Video4Linux > > >Hi, > >Maybe VCM is helpful for you. Please refer to the following URL. >http://marc.info/?l=linux-mm&m=129255940319217&w=2 > >Best regards, > > Jonghun Han > > >Wednesday, February 09, 2011 4:52 PM Hans Verkuil wrote: > >> -----Original Message----- >> From: linux-media-ow...@vger.kernel.org [mailto:linux-media- >> ow...@vger.kernel.org] On Behalf Of Hans Verkuil >> Sent: Wednesday, February 09, 2011 4:52 PM >> To: Wang, Wen W; Jozef Kruger >> Cc: Kanigeri, Hari K; Iyer, Sundar; Yang, Jianwei; >> linux-media@vger.kernel.org >> Subject: Re: Memory allocation in Video4Linux >> >> On Wednesday, February 09, 2011 08:27:27 Wang, Wen W wrote: >> > Hi Hari, >> > >> > You are right. What we need is virtual address. >> > >> > Currently we alloc pages (alloc_pages()) for any request. Store those >> > pages for >> an image buffer into a list. We also manage the virtual address for ISP by >> ourself >> (the range from 0 to 4GB) and the page table for our MMU which is >> independent to >> system MMU page table. >> >> Assuming you are using video4linux for this driver, then you should take a >> look at >> the new videobuf2 framework that will appear in 2.6.39. It is already in the >> media >> tree (http://git.linuxtv.org/media_tree.git, see >> include/media/videobuf2-core.h). >> >> It is much better than the old videobuf framework, and in particular gives >> the driver >> much more control on how memory is allocated and used. >> >> Regards, >> >> Hans >> >> > >> > Thanks >> > Wen >> > >> > >-----Original Message----- >> > >From: Kanigeri, Hari K >> > >Sent: 2011年2月9日 15:22 >> > >To: Iyer, Sundar; Wang, Wen W; Yang, Jianwei; >> > >linux-media@vger.kernel.org; >> > >umg-meego-handset-ker...@umglistsvr.jf.intel.com >> > >Cc: Jozef Kruger >> > >Subject: RE: Memory allocation in Video4Linux >> > > >> > > >> > > >> > >> -----Original Message----- >> > >> From: umg-meego-handset-kernel-boun...@umglistsvr.jf.intel.com >> > >> [mailto:umg-meego-handset-kernel-boun...@umglistsvr.jf.intel.com] >> > >> On Behalf Of Iyer, Sundar >> > >> Sent: Wednesday, February 09, 2011 12:20 PM >> > >> To: Wang, Wen W; Yang, Jianwei; linux-media@vger.kernel.org; >> > >> umg-meego- handset-ker...@umglistsvr.jf.intel.com >> > >> Cc: Jozef Kruger >> > >> Subject: Re: [Umg-meego-handset-kernel] Memory allocation in >> > >> Video4Linux >> > >> >> > >> I remember some Continous Memory Allocator (CMA) being iterated >> > >> down a few versions on some mailing lists? IIRC, it is also for >> > >> large buffers and management for video IPs. >> > > >> > >I believe CMA is for allocating physically contiguous memory and from >> > >what Wen mentioned he also needs virtual memory management, which the >> > >IOMMU will provide. Please check the open source discussion on CMA, >> > >the last I heard CMA proposal was shot down. >> > >Reference: http://www.spinics.net/lists/linux-media/msg26875.html >> > > >> > >Wen, how are you currently allocating physical memory ? >> > > >> > > >> > >Thank you, >> > >Best regards, >> > >Hari >> > 翳 .n +% 遍荻 w .n 伐 {炳g n r■ ㄨ&｛ 夸z罐 >zf＂ >> > 赙z_璁 :+v )撸 >> > >> > >> >> -- >> Hans Verkuil - video4linux developer - sponsored by Cisco >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-media" in >> the body >> of a message to majord...@vger.kernel.org More majordomo info at >> http://vger.kernel.org/majordomo-info.html
