Commit b7d90e7a authored by Michal Hocko's avatar Michal Hocko Committed by Linus Torvalds
Browse files

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@kernel.org


Signed-off-by: default avatarMichal Hocko <mhocko@suse.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Neil Brown <neilb@suse.de>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Uladzislau Rezki <urezki@gmail.com>
Cc: Ilya Dryomov <idryomov@gmail.com>
Cc: Jeff Layton <jlayton@kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 3252b1d8

mm/vmalloc.c

+10 −2
Original line number Diff line number Diff line
@@ -2983,8 +2983,16 @@ static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask, 
 * @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

 */