memcg: unify force charging conditions

memcg: unify force charging conditions

Currently the kernel force charges the allocations which have __GFP_HIGH
flag without triggering the memory reclaim.  __GFP_HIGH indicates that the
caller is high priority and since commit 869712fd3de5 ("mm: memcontrol:
fix network errors from failing __GFP_ATOMIC charges") the kernel lets
such allocations do force charging.  Please note that __GFP_ATOMIC has
been replaced by __GFP_HIGH.

__GFP_HIGH does not tell if the caller can block or can trigger reclaim.
There are separate checks to determine that.  So, there is no need to skip
reclaiming for __GFP_HIGH allocations.  So, handle __GFP_HIGH together
with __GFP_NOFAIL which also does force charging.

Please note that this is a noop change as there are no __GFP_HIGH
allocators in the kernel which also have __GFP_ACCOUNT (or SLAB_ACCOUNT)
and does not allow reclaim for now.

Link: https://lkml.kernel.org/r/20220211064917.2028469-3-shakeelb@google.com
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Reviewed-by: Roman Gushchin <guro@fb.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Chris Down <chris@chrisdown.name>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>