one more information, I am trying with kernel version 2.6.33.5 (x86_64) On Sun, Oct 17, 2010 at 10:52 PM, Rajat Sharma <[email protected]> wrote:
> Hi, > > I was trying to attempt DIRECT I/O on 4K aligned kernel buffer, but it > looks like filesystems are not happy with kernel buffers. I tried doing IO > on ext3, ext4 and NFS. Also I tried to allocate kernel buffer with kmalloc, > vmalloc and static kernel buffer, but nothing help. > > My guess is get_user_pages called to pin pages in memory is not happy with > kernel pages and it is returning -EFAULT. > > As a workaround, I tried to map virtual memory in process address space > using do_mmap and it worked fine. Although it helped, it looks like a hack > and causes performance penalty. > > Please let me know if there is another cleaner way of doing this? > > Thanks, > Rajat >
