Hi, running the snapd tests on i386 I see the following error that could be related to this. It is failing with pc-kernel on beta and candidate but I coun't reproduce it with the version on stable. 

> snap list
Name       Version        Rev   Tracking   Publisher   Notes
core       16-2.39.1      7122  beta       canonical*  core
pc         16.04-0.10     34    candidate  canonical*  gadget
pc-kernel  4.4.0-149.175  219   candidate  canonical*  kernel

Logs:
May 30 03:57:34 localhost.localdomain snapd[23208]: May 30 03:57:33 localhost.localdomain kernel: vmap allocation for size 73728 failed: use vmalloc=<size> to increase size.
May 30 03:57:34 localhost.localdomain snapd[23208]: May 30 03:57:33 localhost.localdomain kernel: vmalloc: allocation failure: 68497 bytes
May 30 03:57:34 localhost.localdomain snapd[23208]: May 30 03:57:33 localhost.localdomain kernel: apparmor_parser: page allocation failure: order:0, mode:0x24000c2
May 30 03:57:34 localhost.localdomain snapd[23208]: May 30 03:57:33 localhost.localdomain kernel: CPU: 1 PID: 23415 Comm: apparmor_parser Not tainted 4.4.0-149-generic #175-Ubuntu
May 30 03:57:34 localhost.localdomain snapd[23208]: May 30 03:57:33 localhost.localdomain kernel: Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
May 30 03:57:34 localhost.localdomain snapd[23208]: May 30 03:57:33 localhost.localdomain kernel:  c1b15967 70e2bd9c 00000286 d0cf7e00 c13c12ef c1a1ce6c 00000001 d0cf7e30
May 30 03:57:34 localhost.localdomain snapd[23208]: May 30 03:57:33 localhost.localdomain kernel:  c11821b6 c1a1b220 f479a700 00000000 024000c2 d0cf7e44 c1a1ce6c d0cf7e18
May 30 03:57:34 localhost.localdomain snapd[23208]: May 30 03:57:33 localhost.localdomain kernel:  70e2bd9c 00010b91 00000000 d0cf7e60 c11ba86f 024000c2 00000000 c1a1ce6c
May 30 03:57:34 localhost.localdomain snapd[23208]: May 30 03:57:33 localhost.localdomain kernel: Call Trace:
May 30 03:57:34 localhost.localdomain snapd[23208]: May 30 03:57:33 localhost.localdomain kernel:  [<c13c12ef>] dump_stack+0x58/0x79
May 30 03:57:34 localhost.localdomain snapd[23208]: May 30 03:57:33 localhost.localdomain kernel:  [<c11821b6>] warn_alloc_failed+0xd6/0x110
May 30 03:57:34 localhost.localdomain snapd[23208]: May 30 03:57:33 localhost.localdomain kernel:  [<c11ba86f>] __vmalloc_node_range+0x1ef/0x210
May 30 03:57:34 localhost.localdomain snapd[23208]: May 30 03:57:33 localhost.localdomain kernel:  [<c11ba8f6>] __vmalloc_node+0x66/0x70
May 30 03:57:34 localhost.localdomain snapd[23208]: May 30 03:57:33 localhost.localdomain kernel:  [<c134f978>] ? __aa_kvmalloc+0x28/0x60
May 30 03:57:34 localhost.localdomain snapd[23208]: May 30 03:57:33 localhost.localdomain kernel:  [<c11ba978>] vmalloc+0x38/0x40
May 30 03:57:34 localhost.localdomain snapd[23208]: May 30 03:57:33 localhost.localdomain kernel:  [<c134f978>] ? __aa_kvmalloc+0x28/0x60
May 30 03:57:34 localhost.localdomain snapd[23208]: May 30 03:57:33 localhost.localdomain kernel:  [<c134f978>] __aa_kvmalloc+0x28/0x60
May 30 03:57:34 localhost.localdomain snapd[23208]: May 30 03:57:33 localhost.localdomain kernel:  [<c134a7f4>] aa_simple_write_to_buffer+0x34/0x90
May 30 03:57:34 localhost.localdomain snapd[23208]: May 30 03:57:33 localhost.localdomain kernel:  [<c134bf93>] policy_update+0x73/0x230
May 30 03:57:34 localhost.localdomain snapd[23208]: May 30 03:57:33 localhost.localdomain kernel:  [<c1314dce>] ? security_file_permission+0x3e/0xd0
May 30 03:57:34 localhost.localdomain snapd[23208]: May 30 03:57:33 localhost.localdomain kernel:  [<c134c1e8>] profile_replace+0x98/0xe0
May 30 03:57:34 localhost.localdomain snapd[23208]: May 30 03:57:33 localhost.localdomain kernel:  [<c134c150>] ? policy_update+0x230/0x230
May 30 03:57:34 localhost.localdomain snapd[23208]: May 30 03:57:33 localhost.localdomain kernel:  [<c11ec782>] __vfs_write+0x22/0x50
May 30 03:57:34 localhost.localdomain snapd[23208]: May 30 03:57:33 localhost.localdomain kernel:  [<c11eceac>] vfs_write+0x8c/0x1b0
May 30 03:57:34 localhost.localdomain snapd[23208]: May 30 03:57:33 localhost.localdomain kernel:  [<c11ed8a1>] SyS_write+0x51/0xb0
May 30 03:57:34 localhost.localdomain snapd[23208]: May 30 03:57:33 localhost.localdomain kernel:  [<c10038df>] do_fast_syscall_32+0x9f/0x190
May 30 03:57:34 localhost.localdomain snapd[23208]: May 30 03:57:33 localhost.localdomain kernel:  [<c17e80b0>] sysenter_past_esp+0x3d/0x61
May 30 03:57:34 localhost.localdomain snapd[23208]: May 30 03:57:33 localhost.localdomain kernel: Mem-Info:
May 30 03:57:34 localhost.localdomain snapd[23208]: May 30 03:57:33 localhost.localdomain kernel: active_anon:10318 inactive_anon:1512 isolated_anon:0
May 30 03:57:34 localhost.localdomain snapd[23208]:                                                active_file:77754 inactive_file:23998 isolated_file:0
May 30 03:57:34 localhost.localdomain snapd[23208]:                                                unevictable:0 dirty:551 writeback:0 unstable:0
May 30 03:57:34 localhost.localdomain snapd[23208]:                                                slab_reclaimable:7394 slab_unreclaimable:13711
May 30 03:57:34 localhost.localdomain snapd[23208]:                                                mapped:8666 shmem:5783 pagetables:212 bounce:0
May 30 03:57:34 localhost.localdomain snapd[23208]:                                                free:304867 free_pcp:672 free_cma:0
May 30 03:57:34 localhost.localdomain snapd[23208]: May 30 03:57:33 localhost.localdomain kernel: DMA free:8796kB min:788kB low:984kB high:1180kB active_anon:480kB inactive_anon:36kB active_file:3152kB inactive_file:608kB unevictable:0kB isolated(anon):0kB isolated(file):0kB present:15992kB managed:15916kB mlocked:0kB dirty:4kB writeback:0kB mapped:724kB shmem:208kB slab_reclaimable:188kB slab_unreclaimable:800kB kernel_stack:8kB pagetables:4kB unstable:0kB bounce:0kB free_pcp:0kB local_pcp:0kB free_cma:0kB writeback_tmp:0kB pages_scanned:0 all_unreclaimable? no
May 30 03:57:34 localhost.localdomain snapd[23208]: May 30 03:57:33 localhost.localdomain kernel: lowmem_reserve[]: 0 834 1942 1942
May 30 03:57:34 localhost.localdomain snapd[23208]: May 30 03:57:33 localhost.localdomain kernel: Normal free:388000kB min:42432kB low:53040kB high:63648kB active_anon:18620kB inactive_anon:1112kB active_file:149332kB inactive_file:34072kB unevictable:0kB isolated(anon):0kB isolated(file):0kB present:897016kB managed:862444kB mlocked:0kB dirty:1320kB writeback:0kB mapped:12612kB shmem:5732kB slab_reclaimable:29388kB slab_unreclaimable:54044kB kernel_stack:1072kB pagetables:488kB unstable:0kB bounce:0kB free_pcp:1384kB local_pcp:652kB free_cma:0kB writeback_tmp:0kB pages_scanned:0 all_unreclaimable? no
May 30 03:57:34 localhost.localdomain snapd[23208]: May 30 03:57:33 localhost.localdomain kernel: lowmem_reserve[]: 0 0 8863 8863
May 30 03:57:34 localhost.localdomain snapd[23208]: May 30 03:57:33 localhost.localdomain kernel: HighMem free:822672kB min:512kB low:14600kB high:28688kB active_anon:22172kB inactive_anon:4900kB active_file:158532kB inactive_file:61312kB unevictable:0kB isolated(anon):0kB isolated(file):0kB present:1134472kB managed:1134472kB mlocked:0kB dirty:880kB writeback:0kB mapped:21328kB shmem:17192kB slab_reclaimable:0kB slab_unreclaimable:0kB kernel_stack:0kB pagetables:356kB unstable:0kB bounce:0kB free_pcp:1296kB local_pcp:696kB free_cma:0kB writeback_tmp:0kB pages_scanned:0 all_unreclaimable? no
May 30 03:57:34 localhost.localdomain snapd[23208]: May 30 03:57:33 localhost.localdomain kernel: lowmem_reserve[]: 0 0 0 0
May 30 03:57:34 localhost.localdomain snapd[23208]: May 30 03:57:33 localhost.localdomain kernel: DMA: 3*4kB (UME) 8*8kB (UM) 5*16kB (UM) 4*32kB (UM) 1*64kB (E) 2*128kB (UM) 2*256kB (UE) 3*512kB (UME) 2*1024kB (ME) 2*2048kB (UE) 0*4096kB = 8796kB
May 30 03:57:34 localhost.localdomain snapd[23208]: May 30 03:57:33 localhost.localdomain kernel: Normal: 383*4kB (ME) 287*8kB (UME) 301*16kB (UME) 558*32kB (ME) 357*64kB (UME) 232*128kB (UME) 89*256kB (ME) 41*512kB (ME) 13*1024kB (M) 7*2048kB (UM) 58*4096kB (M) = 388036kB
May 30 03:57:34 localhost.localdomain snapd[23208]: May 30 03:57:33 localhost.localdomain kernel: HighMem: 26*4kB (M) 53*8kB (UM) 76*16kB (UM) 60*32kB (UM) 20*64kB (UM) 169*128kB (UM) 90*256kB (UM) 62*512kB (UM) 26*1024kB (UM) 13*2048kB (M) 168*4096kB (M) = 822736kB