On Thu, Feb 28, 2019 at 03:38:55PM +0000, Bernard Metzler wrote:
> >> +int siw_mmap(struct ib_ucontext *ctx, struct vm_area_struct *vma)
> >> +{
> >> + struct siw_ucontext *uctx = to_siw_ctx(ctx);
> >> + struct siw_uobj *uobj;
> >> + u32 key = vma->vm_pgoff << PAGE_SHIFT;
> >> + int size = vma->vm_end - vma->vm_start;
> >> + int rv = -EINVAL;
> >> +
> >> + /*
> >> + * Must be page aligned
> >> + */
> >> + if (vma->vm_start & (PAGE_SIZE - 1)) {
> >> + pr_warn("map not page aligned\n");
> >> + goto out;
> >> + }
> >> +
> >> + uobj = siw_remove_uobj(uctx, key, size);
> >> + if (!uobj) {
> >> + pr_warn("mmap lookup failed: %u, %d\n", key, size);
> >> + goto out;
> >> + }
> >
> >EFA used to remove the objects from the list on mmap and we were
> >asked by Jason
> >to keep them in the list until dealloc_ucontext. This way multiple
> >mmaps could
> >work as well.
>
> siw user land library currently does not support multiple mappings of
> the same object, will consider in the future.
We should have sane semantics for mmap and related - don't discard the
offset once it is exposed unless really necessary.
And this thing with search a list is not great, use a cyclic xarray to
generate and find the unique offset cookies.
Jason
