mm: swap: allow cache reclaim to skip slot cache

Currently we free the reclaimed slots through slot cache even if the slot
is required to be empty immediately.  As a result the reclaim caller will
see the slot still occupied even after a successful reclaim, and need to
keep reclaiming until slot cache get flushed.  This caused ineffective or
over reclaim when SWAP is under stress.

So introduce a new flag allowing the slot to be emptied bypassing the slot
cache.

[[email protected]: small folios should have nr_pages == 1 but not nr_page == 0]
  Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Kairui Song <[email protected]>
Reported-by: Barry Song <[email protected]>
Cc: Chris Li <[email protected]>
Cc: "Huang, Ying" <[email protected]>
Cc: Hugh Dickins <[email protected]>
Cc: Kalesh Singh <[email protected]>
Cc: Ryan Roberts <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

0 files changed, 0 insertions, 0 deletions