mm: vmscan: fix force-scanning small targets without swap
mm: vmscan: fix force-scanning small targets without swap

Without swap, anonymous pages are not scanned.  As such, they should not
count when considering force-scanning a small target if there is no swap.

Otherwise, targets are not force-scanned even when their effective scan
number is zero and the other conditions--kswapd/memcg--apply.

This fixes 246e87a93934 ("memcg: fix get_scan_count() for small
targets").

[5c1e68b099950c134891f0b6e179498a8ebe9cf9@linux-foundation.org: fix comment]
Signed-off-by: Johannes Weiner <5332d5d6802f0c4180a1f65eb38cf05f0ccdfd97@redhat.com>
Acked-by: KAMEZAWA Hiroyuki <634f508bd7c47cf0ee4126243675c3e598920fbc@jp.fujitsu.com>
Reviewed-by: Michal Hocko <829500b200af6c2a0eca4dfd5c388e6b8fbe8dc6@suse.cz>
Cc: Ying Han <ac3103168222bc871c4c4626b935581739d3d72b@google.com>
Cc: Balbir Singh <ac7b77b73f9d2cc0faddd296218dde0558e170e3@gmail.com>
Cc: KOSAKI Motohiro <70a1d3ef3e17a2bb0f09a1b2e6c86f607ed1d6d9@jp.fujitsu.com>
Cc: Daisuke Nishimura <d7ce9d9454f80efacebffaaa82023b8c983997f5@mxp.nes.nec.co.jp>
Acked-by: Mel Gorman <2f629c4d93e35c3d371f0463b040c6ef04a5c1e5@csn.ul.ie>
Signed-off-by: Andrew Morton <5c1e68b099950c134891f0b6e179498a8ebe9cf9@linux-foundation.org>
Signed-off-by: Linus Torvalds <69652caca27c8b940640ad396ab71f93cacec34f@linux-foundation.org>

KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas