> > > > > > : * The preload is done in non-atomic context, thus it allows us
> > > > > > : * to use more permissive allocation masks to be more stable under
> > > > > > : * low memory condition and high memory pressure.
> > > > > > : *
> > > > > > : * Even if it fails we do not really care about that. Just proceed
> > > > > > : * as it is. "overflow" path will refill the cache we allocate from.
> > > > > > : */
> > > > > > : if (!this_cpu_read(ne_fit_preload_node)) {
> > > > > >
> > > > > > Readability nit: local `pva' should be defined here, rather than having
> > > > > > function-wide scope.
> > > > > >
> > > > > > : pva = kmem_cache_alloc_node(vmap_area_cachep, GFP_KERNEL, node);
> > > > > >
> > > > > > Why doesn't this honour gfp_mask? If it's not a bug, please add
> > > > > > comment explaining this.
> > > > > >
> > > > But there is a comment, if understand you correctly:
> > > >
> > > > <snip>
> > > > * Even if it fails we do not really care about that. Just proceed
> > > > * as it is. "overflow" path will refill the cache we allocate from.
> > > > <snip>
> > >
> > > My point is that the alloc_vmap_area() caller passed us a gfp_t but
> > > this code ignores it, as does adjust_va_to_fit_type(). These *look*
> > > like potential bugs. If not, they should be commented so they don't
> > > look like bugs any more ;)
> > >
> > I got it, there was misunderstanding from my side :) I agree.
> >
> > In the first case i should have used and respect the passed "gfp_mask",
> > like below:
> >
> > diff --git a/mm/vmalloc.c b/mm/vmalloc.c
> > index f48cd0711478..880b6e8cdeae 100644
> > --- a/mm/vmalloc.c
> > +++ b/mm/vmalloc.c
> > @@ -1113,7 +1113,8 @@ static struct vmap_area *alloc_vmap_area(unsigned long size,
> > * Just proceed as it is. If needed "overflow" path
> > * will refill the cache we allocate from.
> > */
> > - pva = kmem_cache_alloc_node(vmap_area_cachep, GFP_KERNEL, node);
> > + pva = kmem_cache_alloc_node(vmap_area_cachep,
> > + gfp_mask & GFP_RECLAIM_MASK, node);
> >
> > spin_lock(&vmap_area_lock);
> >
> > It should be sent as a separate patch, i think.
>
> Yes. I do not think this would make any real difference because that
> battle is lost long ago. vmalloc is simply not gfp mask friendly. There
> are places like page table allocation which are hardcoded GFP_KERNEL so
> GFP_NOWAIT semantic is not going to work, really. The above makes sense
> from a pure aesthetic POV, though, I would say.
I agree. Then i will create a patch.
Thank you!
--
Vlad Rezki
