Re: [PATCH 1/8] mm: cma: introduce cma_release_nowait()

[Michal Hocko]

On Thu 25-03-21 10:45:19, Michal Hocko wrote:
> On Wed 24-03-21 17:28:28, Mike Kravetz wrote:
> [...]
> >  phys_addr_t cma_get_base(const struct cma *cma)
> >  {
> >  	return PFN_PHYS(cma->base_pfn);
> > @@ -146,6 +155,10 @@ static int __init cma_init_reserved_areas(void)
> >  	for (i = 0; i < cma_area_count; i++)
> >  		cma_activate_area(&cma_areas[i]);
> >  
> > +	cma_release_wq = create_workqueue("cma_release");
> 
> Considering the workqueue is used to free up memory it should likely be
> WQ_MEM_RECLAIM to prevent from long stalls when WQs are overloaded.
> 
> I cannot judge the CMA parts from a very quick glance this looks
> reasonably.

I have overlooked that
+static void cma_clear_bitmap_fn(struct work_struct *work)
+{
+       struct cma_clear_bitmap_work *w;
+
+       w = container_of(work, struct cma_clear_bitmap_work, work);
+
+       cma_clear_bitmap(w->cma, w->pfn, w->count);
+
+       __free_page(pfn_to_page(w->pfn));
+}

should be doing free_contig_range with w->count target.
-- 
Michal Hocko
SUSE Labs