On __pollwait function issue.

Below is result of perf report:

...............................
       │ mov %r13,%rdi ▒
       │ mov 0x8(%rdx),%rax ▒
       │ add $0x10,%rsi ▒
       │ movl $0x0,(%rsi) ▒
 38,10 │ movq $0xffffffff81221860,0x10(%rsi) ▒
       │ mov %rdx,0x8(%rsi) ▒
       │ mov %rax,-0x8(%rsi) ▒
       │ callq 0xffffffff810c3490 ▒
       │7e:┌─→add $0x8,%rsp ▒
  4,76 │ │ pop %rbx ▒
       │ │ pop %r12 ▒
       │ │ pop %r13 ▒
       │ │ pop %rbp ▒
       │ │← retq ▒
       │89:│ xor %esi,%esi ▒
       │ │ mov $0x24000c0,%edi ▒
       │ │ mov %rdx,-0x20(%rbp) ▒
       │ │ callq 0xffffffff81192200 ▒
       │ │ test %rax,%rax ▒
       │ │ mov -0x20(%rbp),%rdx ▒
       │ │↓ je d2 ▒
       │ │ lea 0x10(%rax),%rcx ▒
       │ │ mov %rbx,(%rax) ▒
  4,76 │ │ mov %rax,%rbx ▒
       │ │ mov %rcx,0x8(%rax) ▒
       │ │ mov %rax,0x10(%rdx) ▒
       │ │ mov 0x8(%rax),%rsi ▒
  9,52 │ │ lea 0x40(%rsi),%rcx ▒
       │ │↑ jmp 42 ▒
 14,29 │be:│ lea 0x1(%rax),%ecx ▒
       │ │ shl $0x6,%rax ▒
       │ │ lea 0x30(%rdx,%rax,1),%rsi ▒
  4,76 │ │ mov %ecx,0x28(%rdx) ▒
       │ │↑ jmpq 46
..................................

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: linux-image-4.4.0-28-generic 4.4.0-28.47
ProcVersionSignature: Ubuntu 4.4.0-28.47-generic 4.4.13
Uname: Linux 4.4.0-28-generic x86_64
ApportVersion: 2.20.1-0ubuntu2.1
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: asu 3005 F.... pulseaudio
CurrentDesktop: MATE
Date: Tue Jul 12 17:04:30 2016
InstallationDate: Installed on 2016-04-29 (74 days ago)
InstallationMedia: Ubuntu-Studio 16.04 LTS "Xenial Xerus" - Release amd64 (20160420.1)
IwConfig:
 lo no wireless extensions.

 enp1s0 no wireless extensions.
MachineType: Olidata S.p.A. ALABAMA
ProcFB: 0 inteldrmfb
ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-4.4.0-28-generic root=/dev/mapper/192--168--0--108--vg-root ro
RelatedPackageVersions:
 linux-restricted-modules-4.4.0-28-generic N/A
 linux-backports-modules-4.4.0-28-generic N/A
 linux-firmware 1.157.2
RfKill:

SourcePackage: linux
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 07/08/2008
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: S0101
dmi.board.asset.tag: To Be Filled By O.E.M.
dmi.board.name: To be filled by O.E.M.
dmi.board.vendor: To be filled by O.E.M.
dmi.board.version: To be filled by O.E.M.
dmi.chassis.asset.tag: To Be Filled By O.E.M.
dmi.chassis.type: 3
dmi.chassis.vendor: To Be Filled By O.E.M.
dmi.chassis.version: To Be Filled By O.E.M.
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvrS0101:bd07/08/2008:svnOlidataS.p.A.:pnALABAMA:pvrToBeFilledByO.E.M.:rvnTobefilledbyO.E.M.:rnTobefilledbyO.E.M.:rvrTobefilledbyO.E.M.:cvnToBeFilledByO.E.M.:ct3:cvrToBeFilledByO.E.M.:
dmi.product.name: ALABAMA
dmi.product.version: To Be Filled By O.E.M.
dmi.sys.vendor: Olidata S.p.A.