On Wed, May 19, 2004 at 03:29:09PM -0700, Steve Watt wrote: > >On Wed, May 19, 2004 at 05:29:07AM -0700, Alfred Perlstein wrote: > >+> I need to share about 100megs of memory between kernel and userspace. > >+> > >+> The memory can not be paged and should appear contig in the process's > >+> address space. Any suggestions? > >+> > > The way we accomplished this in some other operating system was to > create a shared memory segment with an implementation-reserved > name, and then have the application shm_open the name and mmap it in. > > Shouldn't be hard with a device driver.
This sounds like the way to go. The way I achieved this with a PCMCIA memory card was to kmem_alloc_nofault() a range and then pmap_map() it, then handle mmap() as per the regular character device case. Do bear in mind that 100 megs is quite large in relative terms, so it's possible that kmem_alloc_nofault() would fail. Regards, BMS _______________________________________________ [EMAIL PROTECTED] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to "[EMAIL PROTECTED]"