mm: swapoff: take notice of completion sooner
authorHugh Dickins <hughd@google.com>
Fri, 19 Apr 2019 00:50:09 +0000 (17:50 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Fri, 19 Apr 2019 16:46:04 +0000 (09:46 -0700)
commit64165b1affc5bc16231ac971e66aae7d68d57f2c
treef076121056eafaf3790cbc23cc0be88b4bc85d79
parentdd862deb151aad2548e72b077a82ad3aa91b715f
mm: swapoff: take notice of completion sooner

The old try_to_unuse() implementation was driven by find_next_to_unuse(),
which terminated as soon as all the swap had been freed.

Add inuse_pages checks now (alongside signal_pending()) to stop scanning
mms and swap_map once finished.

The same ought to be done in shmem_unuse() too, but never was before,
and needs a different interface: so leave it as is for now.

Link: http://lkml.kernel.org/r/alpine.LSU.2.11.1904081258200.1523@eggly.anvils
Fixes: b56a2d8af914 ("mm: rid swapoff of quadratic complexity")
Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: "Alex Xu (Hello71)" <alex_y_xu@yahoo.ca>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Kelley Nielsen <kelleynnn@gmail.com>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Rik van Riel <riel@surriel.com>
Cc: Vineeth Pillai <vpillai@digitalocean.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm/swapfile.c