User-Agent:       Mozilla/5.0 (X11; Linux x86_64; rv:38.9) Gecko/20100101
Goanna/2.1 Firefox/38.9 PaleMoon/26.4.0.1
Build Identifier: 

just had a full system crash with the following message and about 800 mb ram
free with about 1 Gb usage of swap in zswap. i tried opening an image in
firefox. can't reproduce yet.

Sep 07 11:06:21 crest kernel: BUG: unable to handle kernel paging request at
ffffea00ffffff00
Sep 07 11:06:22 crest kernel: IP: [<ffffffff81209c74>] obj_malloc+0x44/0x110
Sep 07 11:06:22 crest kernel: PGD 19f7e2067 PUD 0 
Sep 07 11:06:22 crest kernel: Oops: 0000 [#1] PREEMPT SMP
Sep 07 11:06:22 crest kernel: Modules linked in: overlay xts gf128mul arc4 md4
md5 nls_utf8 cifs dns_resolver fscache fuse zram lz4_compress nf_log_ipv6
xt_pkttype nf_log_ipv4 nf_log_common xt_LOG xt_limit af_packet iscsi_ibft
iscsi_boot_sysfs msr dm_crypt algif_skcipher af_alg snd_hda_codec_realtek
snd_hda_codec_generic snd_hda_codec_hdmi snd_hda_intel snd_hda_codec
snd_hda_core snd_hwdep dm_mod snd_pcm snd_timer coretemp r8169 iTCO_wdt snd
iTCO_vendor_support gpio_ich joydev soundcore kvm_intel lpc_ich mii mfd_core
kvm acpi_cpufreq ppdev ip6t_REJECT tpm_tis fjes parport_pc button
nf_reject_ipv6 tpm parport shpchp i2c_i801 xt_tcpudp irqbypass
nf_conntrack_ipv6 nf_defrag_ipv6 ip6table_raw ipt_REJECT nf_reject_ipv4
iptable_raw xt_CT iptable_filter ip6table_mangle nf_conntrack_netbios_ns
nf_conntrack_broadcast nf_conntrack_ipv4
Sep 07 11:06:22 crest kernel:  nf_defrag_ipv4 ip_tables xt_conntrack
nf_conntrack ip6table_filter ip6_tables x_tables btrfs xor raid6_pq hid_generic
usbhid uas usb_storage ata_generic ata_piix amdkfd amd_iommu_v2 serio_raw
radeon i2c_algo_bit drm_kms_helper syscopyarea sysfillrect sysimgblt
fb_sys_fops ttm drm ehci_pci uhci_hcd ehci_hcd usbcore usb_common sg
Sep 07 11:06:22 crest kernel: CPU: 1 PID: 38 Comm: kswapd0 Not tainted
4.7.2-1-default #1
Sep 07 11:06:22 crest kernel: Hardware name: FUJITSU                         
ESPRIMO P2560                 /D3041-A1, BIOS 6.00 R1.02.3041.A1              
11/09/2010
Sep 07 11:06:22 crest kernel: task: ffff8800db6da080 ti: ffff8800db6dc000
task.ti: ffff8800db6dc000
Sep 07 11:06:22 crest kernel: RIP: 0010:[<ffffffff81209c74>] 
[<ffffffff81209c74>] obj_malloc+0x44/0x110
Sep 07 11:06:22 crest kernel: RSP: 0000:ffff8800db6df8b0  EFLAGS: 00010286
Sep 07 11:06:22 crest kernel: RAX: 00ffffff00ffffff RBX: ffffea0001698080 RCX:
ffffea00ffffff00
Sep 07 11:06:22 crest kernel: RDX: ffff88013e26a7a1 RSI: ffffea0000000000 RDI:
0000000000000060
Sep 07 11:06:22 crest kernel: RBP: ffff8800d2626540 R08: 00000000007fffff R09:
0000000000000000
Sep 07 11:06:22 crest kernel: R10: ffff8800d19f4039 R11: 000000000000003c R12:
ffff88013e26a7a0
Sep 07 11:06:22 crest kernel: R13: ffff88013e26a7a0 R14: ffff8800d2626540 R15:
0000000000000000
Sep 07 11:06:22 crest kernel: FS:  0000000000000000(0000)
GS:ffff88019fd00000(0000) knlGS:0000000000000000
Sep 07 11:06:22 crest kernel: CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
Sep 07 11:06:22 crest kernel: CR2: ffffea00ffffff00 CR3: 0000000053b94000 CR4:
00000000000406e0
Sep 07 11:06:22 crest kernel: Stack:
Sep 07 11:06:22 crest kernel:  ffff8800db6da080 0000000002000202
ffff880195acac80 ffffffff8120a917
Sep 07 11:06:22 crest kernel:  ffffea0001698080 ffff8800d19f4000
ffff88011a864ffe 0000000000001000
Sep 07 11:06:22 crest kernel:  ffff880198a1f300 0000000000000000
ffff8800db6df9a8 ffff8800db6da080
Sep 07 11:06:22 crest kernel: Call Trace:
Sep 07 11:06:22 crest kernel:  [<ffffffff8120a917>] zs_malloc+0xa7/0x3f0
Sep 07 11:06:22 crest kernel:  [<ffffffffa07d01d8>] zram_bvec_rw+0x4b8/0x9d0
[zram]
Sep 07 11:06:22 crest kernel:  [<ffffffffa07d07ad>] zram_rw_page+0xbd/0x120
[zram]
Sep 07 11:06:22 crest kernel:  [<ffffffff812488e5>] bdev_write_page+0xa5/0xf0
Sep 07 11:06:22 crest kernel:  [<ffffffff811d51b3>]
__swap_writepage+0x163/0x290
Sep 07 11:06:22 crest kernel:  [<ffffffff811a1b58>] pageout.isra.42+0x158/0x270
Sep 07 11:06:22 crest kernel:  [<ffffffff811a3ef1>]
shrink_page_list+0x7b1/0x8b0
Sep 07 11:06:22 crest kernel:  [<ffffffff811a464f>]
shrink_inactive_list+0x1df/0x4e0
Sep 07 11:06:22 crest kernel:  [<ffffffff811a5206>]
shrink_zone_memcg+0x546/0x6c0
Sep 07 11:06:22 crest kernel:  [<ffffffff811a545a>] shrink_zone+0xda/0x2f0
Sep 07 11:06:22 crest kernel:  [<ffffffff811a668d>] kswapd+0x50d/0x850
Sep 07 11:06:22 crest kernel:  [<ffffffff8109affd>] kthread+0xbd/0xe0
Sep 07 11:06:22 crest kernel:  [<ffffffff816bb71f>] ret_from_fork+0x1f/0x40
Sep 07 11:06:22 crest kernel: DWARF2 unwinder stuck at ret_from_fork+0x1f/0x40
Sep 07 11:06:22 crest kernel: 
Sep 07 11:06:22 crest kernel: Leftover inexact backtrace:
Sep 07 11:06:22 crest kernel:  [<ffffffff8109af40>] ?
kthread_worker_fn+0x170/0x170
Sep 07 11:06:22 crest kernel: Code: 8b 46 10 48 be 00 00 00 00 00 ea ff ff 8b
7f 18 48 89 c1 49 89 c0 48 c1 e9 1e 49 d1 e8 48 c1 e1 06 41 81 e0 ff ff ff 1f
48 01 f1 <48> 8b 31 f7 c6 00 08 00 00 75 04 4c 8b 49 10 65 ff 05 06 37 e0 
Sep 07 11:06:22 crest kernel: RIP  [<ffffffff81209c74>] obj_malloc+0x44/0x110

Reproducible: Didn't try