Messages in this thread | | | Date | Wed, 16 Feb 2011 10:39:41 +0530 | From | Ankita Garg <> | Subject | Re: Mapping memory between kernel and user space |
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Hi,
On Tue, Feb 15, 2011 at 12:15:08PM -0500, Sri Ram Vemulpali wrote: > As was suggested I started reading chap 15v from LDD. I ran more into > confusion state. > > I know that virtual address(process space), linear address > (segmentation) and physical address. And how are they resolved from > virtual to physical. > But coming to kernel they distinguish logical address from virtual > address. What is the main difference. > Also, they emphasize on high memory and low memory. Why can not high > memory can be mapped in to kernel completely. > Why is that kernel has less visibility of complete space available on RAM. > Linux MM is it a very specific implementation of linux, or Is that a > traditional implementation. >
You may want to go through the literature available on the VM subsystem. Especially, Mel Gorman's book:
http://ptgmedia.pearsoncmg.com/images/0131453483/downloads/gorman_book.pdf
> what is very minimal implementation of MMU for real time systems. >
Linux VM subsystem for the RT kernel is not different from traditional one. The application has to ensure that it pins/locks its pages during execution.
> Thanks in advance. > > --Sri. > > On Tue, Feb 15, 2011 at 12:54 AM, Ankita Garg <ankita@in.ibm.com> wrote: > > On Wed, Feb 09, 2011 at 06:45:42PM -0500, Sri Ram Vemulpali wrote: > >> Hi all, > >> > >> How do I map some space between kernel and user space. Can anyone > >> point me in to right direction. I was trying to map the packets from > >> my netfilter function to kernel user space, to avoid over head of > >> copying. Thanks in advance. > >> > > > > You can take a look at remap_pfn_range() routine when implementing mmap > > in your driver. > > > > -- > > Regards, > > Ankita Garg (ankita@in.ibm.com) > > Linux Technology Center > > IBM India Systems & Technology Labs, > > Bangalore, India > > > > > > -- > Regards, > Sri.
-- Regards, Ankita Garg (ankita@in.ibm.com) Linux Technology Center IBM India Systems & Technology Labs, Bangalore, India -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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