On function __schedule issue.

[asu]

On function __schedule have bottleneck efect.
Bellow is perf report result:
.............................
- 12,61% 12,61% gmain [kernel.kallsyms] [k] __schedule ▒
     0x40f62674c0854803 ▒
     __GI___libc_poll ▒
     entry_SYSCALL_64_fastpath ▒
     sys_poll ▒
     do_sys_poll ▒
     poll_schedule_timeout ▒
     schedule_hrtimeout_range ▒
     schedule_hrtimeout_range_clock ▒
     schedule ▒
     __schedule
.......................................

  __schedule /proc/kcore
       │ ↓ je 580
       │ mov %gs:0x7e7e9750(%rip),%r14d
       │ movl $0x1,%gs:0x7e7f5a8d(%rip)
       │ cmp %r13,%r12
       │ ↓ je 755
       │ mov %r12,%gs:0x7e7f5a74(%rip)
       │ mov %r14d,%r14d
       │ lock bts %r14,0x2d0(%r12)
       │ mov $0x80000000,%edi
       │ add 0x40(%r12),%rdi
       │ movabs $0x77ff80000000,%rax
       │ cmovb 0x5f059b(%rip),%rax # 0xffffffff81e11010
       │ add %rax,%rdi
       │ mov %rdi,%cr3
       │ nop
       │ nop
       │2c4: lock btr %r14,0x2d0(%r13)
       │ nop
       │ mov 0x330(%r12),%eax
100,00 │ test %eax,%eax
       │ ↓ je 6d1
       │ mov %gs:0x7e7f5a26(%rip),%rax
       │ mov %rax,%rdi
       │ or $0x100,%rdi
       │ cmp %rdi,%rax
       │ ↓ je 308
..................

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: linux-image-4.4.0-22-generic 4.4.0-22.40
ProcVersionSignature: Ubuntu 4.4.0-22.40-generic 4.4.8
Uname: Linux 4.4.0-22-generic x86_64
ApportVersion: 2.20.1-0ubuntu2.1
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/pcmC0D0p: asu 3213 F...m pulseaudio
 /dev/snd/controlC0: asu 3213 F.... pulseaudio
CurrentDesktop: MATE
Date: Sat Jun 11 15:29:36 2016
InstallationDate: Installed on 2016-04-29 (42 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-4.4.0-22-generic root=/dev/mapper/192--168--0--108--vg-root ro
RelatedPackageVersions:
 linux-restricted-modules-4.4.0-22-generic N/A
 linux-backports-modules-4.4.0-22-generic N/A
 linux-firmware 1.157
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.

[Brad Figg (brad-figg)]

This change was made by a bot.

[Joseph Salisbury (jsalisbury)]

This issue appears to be an upstream bug. Would it be possible for you to open an upstream bug report[0]? That will allow the upstream Developers to examine the issue, and may provide a quicker resolution to the bug.

Please follow the instructions on the wiki page[0]. The first step is to email the appropriate mailing list. If no response is received, then a bug may be opened on bugzilla.kernel.org.

Once this bug is reported upstream, please add the tag: 'kernel-bug-reported-upstream'.

[0] https://wiki.ubuntu.com/Bugs/Upstream/kernel