Re: [PATCH RFC v2 06/19] Add a vmalloc_node_user function

[Christoph Hellwig <hch@infradead.org>]

On Mon, Jun 03, 2024 at 11:59:01AM -0400, Kent Overstreet wrote:
> On Fri, May 31, 2024 at 06:56:01AM -0700, Christoph Hellwig wrote:
> > >  void *vmalloc_user(unsigned long size)
> > >  {
> > > -	return __vmalloc_node_range(size, SHMLBA,  VMALLOC_START, VMALLOC_END,
> > > -				    GFP_KERNEL | __GFP_ZERO, PAGE_KERNEL,
> > > -				    VM_USERMAP, NUMA_NO_NODE,
> > > -				    __builtin_return_address(0));
> > > +	return _vmalloc_node_user(size, NUMA_NO_NODE);
> > 
> > But I suspect simply adding a gfp_t argument to vmalloc_node might be
> > a much easier to use interface here, even if it would need a sanity
> > check to only allow for actually useful to vmalloc flags.
> 
> vmalloc doesn't properly support gfp flags due to page table allocation

Which I tried to cover by the above "to only allow for actually useful
to vmalloc flags".  I.e. the __GFP_ZERO used here is useful, as would be
a GFP_USER which we'd probably actually want here as well.