softlockup in find_get_pages after installing kernel-2.6.32-696.23.1

Issue

• After updating to kernel-2.6.32-696.23.1 and doing echo 3 > /proc/sys/vm/drop_caches we see a soft lockup as follows:

BUG: soft lockup - CPU#0 stuck for 67s! [sh:1827]
Modules linked in: autofs4 ipt_REJECT nf_conntrack_ipv4 nf_defrag_ipv4 iptable_filter ip_tables ip6t_REJECT nf_conntrack_ipv6 nf_defrag_ipv6 xt_state nf_conntrack ip6table_filter ip6_tables ipv6 microcode virtio_balloon virtio_net i2c_piix4 i2c_core ext4 jbd2 mbcache virtio_blk virtio_pci virtio_ring virtio pata_acpi ata_generic ata_piix dm_mirror dm_region_hash dm_log dm_mod [last unloaded: speedstep_lib]
CPU 0 
Modules linked in: autofs4 ipt_REJECT nf_conntrack_ipv4 nf_defrag_ipv4 iptable_filter ip_tables ip6t_REJECT nf_conntrack_ipv6 nf_defrag_ipv6 xt_state nf_conntrack ip6table_filter ip6_tables ipv6 microcode virtio_balloon virtio_net i2c_piix4 i2c_core ext4 jbd2 mbcache virtio_blk virtio_pci virtio_ring virtio pata_acpi ata_generic ata_piix dm_mirror dm_region_hash dm_log dm_mod [last unloaded: speedstep_lib]

Pid: 1827, comm: sh Not tainted 2.6.32-696.23.1.el6.x86_64 #1 Red Hat KVM
RIP: 0010:[<ffffffff81130d0f>]  [<ffffffff81130d0f>] find_get_pages+0x13f/0x150
RSP: 0000:ffff88003ccabca8  EFLAGS: 00000246
RAX: ffff88003c1a50d0 RBX: ffff88003ccabcf8 RCX: 000000000000000d
RDX: ffff88003ccabdd0 RSI: 000000000000000e RDI: 0000000000021100
RBP: ffffffff8155f13e R08: 000000000000000e R09: ffff88003ccabc68
R10: 000000000000400e R11: ffff88003c1a50d0 R12: 0000000000000010
R13: ffffffff812a44a4 R14: ffffffffffffff10 R15: ffff88003c1a5050
FS:  00007f9432f6e700(0000) GS:ffff880002200000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
CR2: 00007f8424542010 CR3: 000000003db60000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process sh (pid: 1827, threadinfo ffff88003cca8000, task ffff880037972040)
Stack:
 ffff88003ccabd58 ffff880037ff7e68 ffff88003ccabce8 ffff880037ff7e70
<d> ffff88003ccabd58 ffff88003ccabd58 0000000000000000 ffffffffffffffff
<d> ffff88003ccabd58 ffff880037ff7e68 ffff88003ccabd18 ffffffff81147432
Call Trace:
 [<ffffffff81147432>] ? pagevec_lookup+0x22/0x30
 [<ffffffff81148f44>] ? invalidate_mapping_pages+0x84/0x1e0
 [<ffffffff811cc2ee>] ? drop_caches_sysctl_handler+0x12e/0x1d0
 [<ffffffff81213e9c>] ? proc_sys_call_handler+0x9c/0xd0
 [<ffffffff81213ee4>] ? proc_sys_write+0x14/0x20
 [<ffffffff8119cb5a>] ? vfs_write+0xba/0x1a0
 [<ffffffff8119e056>] ? fget_light_pos+0x16/0x50
 [<ffffffff8119d691>] ? sys_write+0x51/0xb0
 [<ffffffff8155e351>] ? system_call_fastpath+0x2f/0x34
Code: ff ff eb da 45 31 ff eb 99 48 89 55 c0 48 89 4d b0 89 75 b8 e8 b3 6b 01 00 48 8b 55 c0 48 8b 4d b0 8b 75 b8 e9 1a ff ff ff f3 90 <e9> e3 fe ff ff 66 66 66 2e 0f 1f 84 00 00 00 00 00 55 48 89 e5 
Call Trace:
 [<ffffffff81130c0b>] ? find_get_pages+0x3b/0x150
 [<ffffffff81147432>] ? pagevec_lookup+0x22/0x30
 [<ffffffff81148f44>] ? invalidate_mapping_pages+0x84/0x1e0
 [<ffffffff811cc2ee>] ? drop_caches_sysctl_handler+0x12e/0x1d0
 [<ffffffff81213e9c>] ? proc_sys_call_handler+0x9c/0xd0
 [<ffffffff81213ee4>] ? proc_sys_write+0x14/0x20
 [<ffffffff8119cb5a>] ? vfs_write+0xba/0x1a0
 [<ffffffff8119e056>] ? fget_light_pos+0x16/0x50
 [<ffffffff8119d691>] ? sys_write+0x51/0xb0
 [<ffffffff8155e351>] ? system_call_fastpath+0x2f/0x34