From: Christopher Hawkins <chawkins@bp...> - 2010-02-09 17:44:10
> On Tue, 09 Feb 2010, Tejun Heo wrote:
> > Implement FUSE direct mmap support. The server can redirect client
> > mmap requests to any SHMLBA aligned offset in the custom address
> > attached to the fuse channel. The address space is managed by the
> > server using mmap/munmap(2). The SHMLBA alignment requirement is
> > necessary to avoid cache aliasing issues on archs with virtually
> > indexed caches as FUSE direct mmaps are basically shared memory
> > between clients and the server.
> > The direct mmap address space is backed by pinned kernel pages
> > are allocated on the first fault either from a client or the
> > If used carelessly, this can easily waste and drain memory.
> > Currently, a server must have CAP_SYS_ADMIN to manage dmmap regions
> > mmapping and munmapping the channel fd.
I would like to try this out and give feedback, if possible. I have an immediate application for this but I am not sure how to apply these changes... Being new to fuse I am not clear on what parts are kernel based and what parts are userspace. I have a kernel module (and source) with a few optimizations from the glusterfs project. It's version 2.7.4. I also have the latest version 2.8.3, but I see this does not include the kernel module code any longer.
So should I try to apply the diff to the 2.7.4 tree (because it contains kernel module modifications) or does it apply it to the 2.8.3 tree, or to my kernel source tree? I am hoping that a kernel recompile is not needed for the patch to become active.