mm: make slab and vmalloc allocators __GFP_NOLOCKDEP aware
authorMichal Hocko <mhocko@suse.com>
Fri, 14 Jan 2022 22:07:11 +0000 (14:07 -0800)
committerLinus Torvalds <torvalds@linux-foundation.org>
Sat, 15 Jan 2022 14:30:29 +0000 (16:30 +0200)
commit704687deaae768a818d7da0584ee021793a97684
tree950ba1a352142d51585eed89e52dd27e15c2abe2
parenta421ef303008b0ceee2cfc625c3246fa7654b0ca
mm: make slab and vmalloc allocators __GFP_NOLOCKDEP aware

sl?b and vmalloc allocators reduce the given gfp mask for their internal
needs.  For that they use GFP_RECLAIM_MASK to preserve the reclaim
behavior and constrains.

__GFP_NOLOCKDEP is not a part of that mask because it doesn't really
control the reclaim behavior strictly speaking.  On the other hand it
tells the underlying page allocator to disable reclaim recursion
detection so arguably it should be part of the mask.

Having __GFP_NOLOCKDEP in the mask will not alter the behavior in any
form so this change is safe pretty much by definition.  It also adds a
support for this flag to SL?B and vmalloc allocators which will in turn
allow its use to kvmalloc as well.  A lack of the support has been
noticed recently in

  http://lkml.kernel.org/r/20211119225435.GZ449541@dread.disaster.area

Link: https://lkml.kernel.org/r/YZ9XtLY4AEjVuiEI@dhcp22.suse.cz
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reported-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Dave Chinner <dchinner@redhat.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Ilya Dryomov <idryomov@gmail.com>
Cc: Jeff Layton <jlayton@kernel.org>
Cc: Neil Brown <neilb@suse.de>
Cc: Uladzislau Rezki (Sony) <urezki@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm/internal.h