On Fri, 2010-07-30 at 19:39 +0800, Figo.zhang wrote: > On Fri, 2010-07-30 at 11:31 +0200, Laurent Pinchart wrote: > > Hi, > > > > On Friday 30 July 2010 02:08:02 Figo.zhang wrote: > > > a mmap issue for videobuf-dma-sg: it will alloc a new page for mmaping > > > when > > > it encounter page fault at video_vm_ops->fault(). pls see > > > http://www.spinics.net/lists/linux-media/msg21243.html > > > > > > a new implementation for mmap, it translate to vmalloc to page at > > > video_vm_ops->fault(). > > > > > > in v2, if mem->dma.vmalloc is NULL at video_vm_ops->fault(), it will alloc > > > memory by vmlloc_32(). > > > > You're replacing allocation in videobuf_vm_fault by allocationg in > > videobuf_vm_fault. I don't see the point. videobuf_vm_fault needs to go > > away > > completely. > in now videobuf code, the mmap alloc a new buf, the capture dma buffer > using vmalloc() alloc buffer, how is > relationship with them? in usrspace , the mmap region will not the > actual capture dma data, how is work?
hmm, I understand with some mistake before.for mmap in videobuf-sg, it is not call vmalloc_32() to alloc memory, it call videobuf_dma_init_user_locked()->get_user_pages(), and the end, it will handle_mm_fault()-> vm_ops->fault(). Because in mmap(), it have assigned vaule for "baddr" variable. it is too obscure for videobuf-sg, hope for videbuf2. ~~ -- 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
