On Tue, Aug 28, 2007 at 02:00:43PM -0500, Robin Holt wrote: > The ioctl is sort of historical. IIRC, in ProPack 3 (RHEL4 based 2.4 > kernel), we added system calls. When the community started making noise > about system calls being bad, we went to a device special file with a > read/write (couldn't get the needed performance from the ioctl() interface > which used to acquire the BKL). Now that the community fixed the ioctl > issues, we went to using an ioctl, but are completely open to change. > > If you want to introduce system calls, we would expect to need, IIRC, 8. > We also pondered an xpmem filesystem today. It really felt wrong, > but we could pursue that as an alternative.
The problem is not ioctls per s?, but the kind of operation you export. > What is the correct direction to go with this? get_user_pages() does > currently require the task_struct. Are you proposing we develop a way > to fault pages without the task_struct of the owning process/thread group? Stop trying to mess with vmas and get_user_pages on processes entirely. The only region of virtual memory a driver can deal with is the one it got a mmap request for, or when using get_user_pages the one it's got a read/write request for. You're doing a worse variant of the rdma page pinning scheme we're rejected countless times. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
