On Tue 19-10-21 11:44:01, Neil Brown wrote:
> On Mon, 18 Oct 2021, Michal Hocko wrote:
[...]
> > @@ -2930,8 +2932,24 @@ static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask,
> > goto fail;
> > }
> >
> > - if (vmap_pages_range(addr, addr + size, prot, area->pages,
> > - page_shift) < 0) {
> > + /*
> > + * page tables allocations ignore external gfp mask, enforce it
> > + * by the scope API
> > + */
> > + if ((gfp_mask & (__GFP_FS | __GFP_IO)) == __GFP_IO)
> > + flags = memalloc_nofs_save();
> > + else if (!(gfp_mask & (__GFP_FS | __GFP_IO)))
>
> I would *much* rather this were written
>
> else if ((gfp_mask & (__GFP_FS | __GFP_IO)) == 0)
Sure, this looks better indeed.
> so that the comparison with the previous test is more obvious. Ditto
> for similar code below.
> It could even be
>
> switch (gfp_mask & (__GFP_FS | __GFP_IO)) {
> case __GFP__IO: flags = memalloc_nofs_save(); break;
> case 0: flags = memalloc_noio_save(); break;
> }
>
> But I'm not completely convinced that is an improvement.
I am not a great fan of this though.
> In terms of functionality this looks good.
Thanks for the review!
--
Michal Hocko
SUSE Labs
