On Sat, Mar 16, 2013 at 4:39 PM, Will Huck <will.huckk@xxxxxxxxx> wrote: > On 03/15/2013 07:39 PM, Gil Weber wrote: >> I am experiencing an issue with my device driver. I am using mmap and >> ioctl to share information with my user space application. >> The thing is that the shared memory does not seems to be synced. Do check >> this, I have done a simple test: So if I got this right, the issue is that the vmalloc_area is virtually aliased between the kernel and the user space mapping, so that coherency is not guaranteed on architectures that use virtually aliased caches. fs/aio.c does something similar to what you want with their ring buffer. The kernel doesn't access the ring buffer through a vmalloc area like you're trying to do; instead it uses kmap_atomic() .. kunmap_atomic() whenever it wants to access it. I don't actually consider myself an expert in this area but I believe the above should solve your problem :) -- Michel "Walken" Lespinasse A program is never fully debugged until the last user dies. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>