On Fri 05-11-21 13:39:50, Andrew Morton wrote: > From: Michal Hocko <mhocko@xxxxxxxx> > Subject: mm/vmalloc: be more explicit about supported gfp flags > > The core of the vmalloc allocator __vmalloc_area_node doesn't say anything > about gfp mask argument. Not all gfp flags are supported though. Be more > explicit about constraints. > > Link: https://lkml.kernel.org/r/20211020082545.4830-1-mhocko@xxxxxxxxxx > Signed-off-by: Michal Hocko <mhocko@xxxxxxxx> > Cc: Dave Chinner <david@xxxxxxxxxxxxx> > Cc: Neil Brown <neilb@xxxxxxx> > Cc: Christoph Hellwig <hch@xxxxxxxxxxxxx> > Cc: Uladzislau Rezki <urezki@xxxxxxxxx> > Cc: Ilya Dryomov <idryomov@xxxxxxxxx> > Cc: Jeff Layton <jlayton@xxxxxxxxxx> > Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> As already pointed out http://lkml.kernel.org/r/YXE+hcodJ7zxeYA7@xxxxxxxxxxxxxx this patch cannot be applied without other patches from the same series. > --- > > mm/vmalloc.c | 12 ++++++++++-- > 1 file changed, 10 insertions(+), 2 deletions(-) > > --- a/mm/vmalloc.c~mm-vmalloc-be-more-explicit-about-supported-gfp-flags > +++ a/mm/vmalloc.c > @@ -2983,8 +2983,16 @@ fail: > * @caller: caller's return address > * > * Allocate enough pages to cover @size from the page level > - * allocator with @gfp_mask flags. Map them into contiguous > - * kernel virtual space, using a pagetable protection of @prot. > + * allocator with @gfp_mask flags. Please note that the full set of gfp > + * flags are not supported. GFP_KERNEL would be a preferred allocation mode > + * but GFP_NOFS and GFP_NOIO are supported as well. Zone modifiers are not > + * supported. From the reclaim modifiers__GFP_DIRECT_RECLAIM is required (aka > + * GFP_NOWAIT is not supported) and only __GFP_NOFAIL is supported (aka > + * __GFP_NORETRY and __GFP_RETRY_MAYFAIL are not supported). > + * __GFP_NOWARN can be used to suppress error messages about failures. > + * > + * Map them into contiguous kernel virtual space, using a pagetable > + * protection of @prot. > * > * Return: the address of the area or %NULL on failure > */ > _ -- Michal Hocko SUSE Labs
