linux/include
Aaron Lu b0cd52e644 mm/swap: use nr_node_ids for avail_lists in swap_info_struct
[ Upstream commit 66f71da9dd ]

Since a2468cc9bf ("swap: choose swap device according to numa node"),
avail_lists field of swap_info_struct is changed to an array with
MAX_NUMNODES elements.  This made swap_info_struct size increased to 40KiB
and needs an order-4 page to hold it.

This is not optimal in that:
1 Most systems have way less than MAX_NUMNODES(1024) nodes so it
  is a waste of memory;
2 It could cause swapon failure if the swap device is swapped on
  after system has been running for a while, due to no order-4
  page is available as pointed out by Vasily Averin.

Solve the above two issues by using nr_node_ids(which is the actual
possible node number the running system has) for avail_lists instead of
MAX_NUMNODES.

nr_node_ids is unknown at compile time so can't be directly used when
declaring this array.  What I did here is to declare avail_lists as zero
element array and allocate space for it when allocating space for
swap_info_struct.  The reason why keep using array but not pointer is
plist_for_each_entry needs the field to be part of the struct, so pointer
will not work.

This patch is on top of Vasily Averin's fix commit.  I think the use of
kvzalloc for swap_info_struct is still needed in case nr_node_ids is
really big on some systems.

Link: http://lkml.kernel.org/r/20181115083847.GA11129@intel.com
Signed-off-by: Aaron Lu <aaron.lu@intel.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Vasily Averin <vvs@virtuozzo.com>
Cc: Huang Ying <ying.huang@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-01-26 09:32:43 +01:00
..
acpi
asm-generic mm: introduce mm_[p4d|pud|pmd]_folded 2018-12-29 13:37:58 +01:00
clocksource
crypto crypto: speck - remove Speck 2018-11-13 11:08:46 -08:00
drm drm: Get ref on CRTC commit object when waiting for flip_done 2018-10-18 14:23:13 -04:00
dt-bindings ARM: SoC: late updates 2018-08-25 14:12:36 -07:00
keys
kvm
linux mm/swap: use nr_node_ids for avail_lists in swap_info_struct 2019-01-26 09:32:43 +01:00
math-emu
media media: cec: keep track of outstanding transmits 2019-01-09 17:38:46 +01:00
memory
misc
net netfilter: nf_conncount: speculative garbage collection on empty lists 2019-01-22 21:40:29 +01:00
pcmcia pcmcia: remove long deprecated pcmcia_request_exclusive_irq() function 2018-08-18 12:30:42 -07:00
ras
rdma IB/rxe: Revise the ib_wr_opcode enum 2018-11-13 11:08:43 -08:00
scsi SCSI misc on 20180815 2018-08-15 22:06:26 -07:00
soc soc: fsl: qbman: add APIs to retrieve the probing status 2018-09-27 15:43:35 -05:00
sound ALSA: pcm: Fix interval evaluation with openmin/max 2018-12-13 09:16:16 +01:00
target scsi: target/core: Make sure that target_wait_for_sess_cmds() waits long enough 2019-01-26 09:32:38 +01:00
trace sunrpc: use-after-free in svc_process_common() 2019-01-16 22:04:37 +01:00
uapi RDMA/vmw_pvrdma: Return the correct opcode when creating WR 2019-01-22 21:40:34 +01:00
video fbdev changes for v4.19: 2018-08-23 15:44:58 -07:00
xen Revert "xen/balloon: Mark unallocated host memory as UNUSABLE" 2018-12-17 09:24:39 +01:00