Re: KLD mmap question
On Thu, 30 May 2002, Tom Tang wrote: Thanks for the reply, I'll check it out. However if you'll notice in my prev mail, I stated that I was trying to contigmalloc 4K... Hard to believe that the system doesnt have 4K lying around. Good point. Contigmallocing a page is pretty silly, since you get a page anyway. Why not just use normal malloc? Doug White| FreeBSD: The Power to Serve [EMAIL PROTECTED] | www.FreeBSD.org To Unsubscribe: send mail to [EMAIL PROTECTED] with unsubscribe freebsd-hackers in the body of the message
KLD mmap question
Hello, I have a question about implementing mmap functions in device drivers. Thinking it would be simple, I contigmalloc'd a buffer of PAGE_SIZE and returned it using atop like other mmap device implementations. However when my userland program mmaps the device with offset 0, when I try accessing the returned pointer, it returns me invalid memory address. Any help would be appreciated... - Tom -- Tom Tang tangj AT cs DOT ucdavis DOT edu To Unsubscribe: send mail to [EMAIL PROTECTED] with unsubscribe freebsd-hackers in the body of the message
Re: KLD mmap question
On Thu, 30 May 2002, Tom Tang wrote: I have a question about implementing mmap functions in device drivers. Thinking it would be simple, I contigmalloc'd a buffer of PAGE_SIZE and returned it using atop like other mmap device implementations. However when my userland program mmaps the device with offset 0, when I try accessing the returned pointer, it returns me invalid memory address. Any help would be appreciated... Generally, after the machine is started, memory gets too fragmented to use contigmalloc. If you preload the module and do the contigmalloc at attach time it should succeed. Doug White| FreeBSD: The Power to Serve [EMAIL PROTECTED] | www.FreeBSD.org To Unsubscribe: send mail to [EMAIL PROTECTED] with unsubscribe freebsd-hackers in the body of the message
Re: KLD mmap question
Doug, Thanks for the reply, I'll check it out. However if you'll notice in my prev mail, I stated that I was trying to contigmalloc 4K... Hard to believe that the system doesnt have 4K lying around. - Tom On Thu, 30 May 2002, Doug White wrote: On Thu, 30 May 2002, Tom Tang wrote: I have a question about implementing mmap functions in device drivers. Thinking it would be simple, I contigmalloc'd a buffer of PAGE_SIZE and returned it using atop like other mmap device implementations. However when my userland program mmaps the device with offset 0, when I try accessing the returned pointer, it returns me invalid memory address. Any help would be appreciated... Generally, after the machine is started, memory gets too fragmented to use contigmalloc. If you preload the module and do the contigmalloc at attach time it should succeed. Doug White| FreeBSD: The Power to Serve [EMAIL PROTECTED] | www.FreeBSD.org -- Tom Tang [EMAIL PROTECTED] To Unsubscribe: send mail to [EMAIL PROTECTED] with unsubscribe freebsd-hackers in the body of the message
Re: KLD mmap question
On Thu, 2002-05-30 at 13:14, Tom Tang wrote: Hello, I have a question about implementing mmap functions in device drivers. Thinking it would be simple, I contigmalloc'd a buffer of PAGE_SIZE and returned it using atop like other mmap device implementations. However when my userland program mmaps the device with offset 0, when I try accessing the returned pointer, it returns me invalid memory address. Any help would be appreciated... An associated question: while I was looking at the DRM's mmap for the shared memory area, I think I figured out that you didn't need memory that was going to be mmapped to be physically contiguous (since the device pager would get each page of it separately). Was I right? -- Eric Anholt [EMAIL PROTECTED] http://gladstone.uoregon.edu/~eanholt/dri/ To Unsubscribe: send mail to [EMAIL PROTECTED] with unsubscribe freebsd-hackers in the body of the message
