On Wed 16-10-19 11:54:37, Uladzislau Rezki (Sony) wrote: > alloc_vmap_area() is given a gfp_mask for the page allocator. > Let's respect that mask and consider it even in the case when > doing regular CPU preloading, i.e. where a context can sleep. This is explaining what but it doesn't say why. I would go with " Allocation functions should comply with the given gfp_mask as much as possible. The preallocation code in alloc_vmap_area doesn't follow that pattern and it is using a hardcoded GFP_KERNEL. Although this doesn't really make much difference because vmalloc is not GFP_NOWAIT compliant in general (e.g. page table allocations are GFP_KERNEL) there is no reason to spread that bad habit and it is good to fix the antipattern. " > > Signed-off-by: Uladzislau Rezki (Sony) <urezki@xxxxxxxxx> Acked-by: Michal Hocko <mhocko@xxxxxxxx> > --- > mm/vmalloc.c | 8 ++++---- > 1 file changed, 4 insertions(+), 4 deletions(-) > > diff --git a/mm/vmalloc.c b/mm/vmalloc.c > index b7b443bfdd92..593bf554518d 100644 > --- a/mm/vmalloc.c > +++ b/mm/vmalloc.c > @@ -1064,9 +1064,9 @@ static struct vmap_area *alloc_vmap_area(unsigned long size, > return ERR_PTR(-EBUSY); > > might_sleep(); > + gfp_mask = gfp_mask & GFP_RECLAIM_MASK; > > - va = kmem_cache_alloc_node(vmap_area_cachep, > - gfp_mask & GFP_RECLAIM_MASK, node); > + va = kmem_cache_alloc_node(vmap_area_cachep, gfp_mask, node); > if (unlikely(!va)) > return ERR_PTR(-ENOMEM); > > @@ -1074,7 +1074,7 @@ static struct vmap_area *alloc_vmap_area(unsigned long size, > * Only scan the relevant parts containing pointers to other objects > * to avoid false negatives. > */ > - kmemleak_scan_area(&va->rb_node, SIZE_MAX, gfp_mask & GFP_RECLAIM_MASK); > + kmemleak_scan_area(&va->rb_node, SIZE_MAX, gfp_mask); > > retry: > /* > @@ -1100,7 +1100,7 @@ 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, node); > > spin_lock(&vmap_area_lock); > > -- > 2.20.1 > -- Michal Hocko SUSE Labs
