Messages in this thread | | | Date | Thu, 15 May 2008 13:50:27 +0200 | From | Arnd Hannemann <> | Subject | Re: How to avoid data copies in a driver ? |
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Francis Moreau wrote: > Hello, > > On Wed, May 14, 2008 at 11:23 PM, linux-os (Dick Johnson) > <linux-os@analogic.com> wrote: >> You memory-map the data. Impliment mmap() in your driver. >> You can also impliment poll() { select() } so your >> application knows when new data are available. >> >> You cannot use a user-mode file-descriptor in the kernel. >> > > Why not ?
http://kernelnewbies.org/FAQ/WhyWritingFilesFromKernelIsBad
> > I'm suprised because what I need doens't seem so uncommon, usually > devices send or > receive data to/from files. So a helper (system call ?) to achieve > that other than the basic > read/write seems needed, no ?
Usually devices send or receive just data, and they shouldn't care about file format, filesystems, permissions and all this stuff...
Regards, Arnd
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