On Mon, 11 Apr 2016, Michal Hocko wrote:
> From: Michal Hocko <[email protected]> > > copy_params seems to be little bit confused about which allocation flags > to use. It enforces GFP_NOIO even though it uses > memalloc_noio_{save,restore} which enforces GFP_NOIO at the page memalloc_noio_{save,restore} is used because __vmalloc is flawed and doesn't respect GFP_NOIO properly (it doesn't use gfp flags when allocating pagetables). The proper fix it to correct __vmalloc (though, it would require change to pagetable allocation routine on all architectures), not to remove GFP_NOIO from __vmalloc. Mikulas > allocator level automatically (via memalloc_noio_flags). It also > uses __GFP_REPEAT for the __vmalloc request which doesn't make much > sense either because vmalloc doesn't rely on costly high order > allocations. > > Cc: Shaohua Li <[email protected]> > Cc: Mikulas Patocka <[email protected]> > Signed-off-by: Michal Hocko <[email protected]> > --- > drivers/md/dm-ioctl.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/md/dm-ioctl.c b/drivers/md/dm-ioctl.c > index 2adf81d81fca..dfe629a294e1 100644 > --- a/drivers/md/dm-ioctl.c > +++ b/drivers/md/dm-ioctl.c > @@ -1723,7 +1723,7 @@ static int copy_params(struct dm_ioctl __user *user, > struct dm_ioctl *param_kern > if (!dmi) { > unsigned noio_flag; > noio_flag = memalloc_noio_save(); > - dmi = __vmalloc(param_kernel->data_size, GFP_NOIO | > __GFP_REPEAT | __GFP_HIGH | __GFP_HIGHMEM, PAGE_KERNEL); > + dmi = __vmalloc(param_kernel->data_size, __GFP_HIGH | > __GFP_HIGHMEM, PAGE_KERNEL); > memalloc_noio_restore(noio_flag); > if (dmi) > *param_flags |= DM_PARAMS_VMALLOC; > -- > 2.8.0.rc3 >
