FROMLIST: psi: introduce state_mask to represent stalled psi states

The psi monitoring patches will need to determine the same states as
record_times().  To avoid calculating them twice, maintain a state mask
that can be consulted cheaply.  Do this in a separate patch to keep the
churn in the main feature patch at a minimum.

This adds 4-byte state_mask member into psi_group_cpu struct which results
in its first cacheline-aligned part becoming 52 bytes long.  Add explicit
values to enumeration element counters that affect psi_group_cpu struct
size.

Link: http://lkml.kernel.org/r/20190124211518.244221-4-surenb@google.com


Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Li Zefan <lizefan@huawei.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>

(not upstream yet, latest version published at: https://lore.kernel.org/patchwork/patch/1052414/

)

Bug: 127712811
Bug: 129157727
Test: lmkd in PSI mode
Change-Id: I38a1ca3d5c9e6cc3ba39e88c6a9af29ecdc0df5b
Signed-off-by: Suren Baghdasaryan <surenb@google.com>