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| author | Michal Hocko <mhocko@suse.com> | 2021-11-05 21:39:50 +0100 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2021-11-06 21:30:37 +0100 |
| commit | b7d90e7a5ea8d64e668d5685925900d33d3884d5 (patch) | |
| tree | c8b3170c756e83bd1e9a5f28a0eed3dc7f0acb23 /mm/vmalloc.c | |
| parent | kasan: arm64: fix pcpu_page_first_chunk crash with KASAN_VMALLOC (diff) | |
| download | linux-b7d90e7a5ea8d64e668d5685925900d33d3884d5.tar.xz linux-b7d90e7a5ea8d64e668d5685925900d33d3884d5.zip | |
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: Michal 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: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/vmalloc.c')
| -rw-r--r-- | mm/vmalloc.c | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/mm/vmalloc.c b/mm/vmalloc.c index 75fa100f5424..c56720136c45 100644 --- a/mm/vmalloc.c +++ b/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 */ |