Re-implement origianl yield_type 1. Now the supportted yield type as below
0: No yield.
1: Deboost and requeue task. (default)
2: Set rq skip task.

Let new created tasks take less cpu time, and make fairness to existed
tasks.

Reverst the untested code which steath in previous yield() rework.
Do not yield when there is only one task running in the rq.

Fix issue "Linux 5.0.2 BMQ compile fails for x86-UP" alfredchen/bmq#1

Fix issue "Linux 5.0.2 BMQ compile fails for x86-UP" alfredchen/bmq#1

Pull ARM SoC fixes from Arnd Bergmann:
 "One more set of simple ARM platform fixes:

   - A boot regression on qualcomm msm8998

   - Gemini display controllers got turned off by accident

   - incorrect reference counting in optee"

* tag 'armsoc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc:
  tee: optee: add missing of_node_put after of_device_is_available
  arm64: dts: qcom: msm8998: Extend TZ reserved memory area
  ARM: dts: gemini: Re-enable display controller

Pull x86 fixes from Thomas Gleixner:
 "Two last minute fixes:

   - Prevent value evaluation via functions happening in the user access
     enabled region of __put_user() (put another way: make sure to
     evaluate the value to be stored in user space _before_ enabling
     user space accesses)

   - Correct the definition of a Hyper-V hypercall constant"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/hyper-v: Fix definition of HV_MAX_FLUSH_REP_COUNT
  x86/uaccess: Don't leak the AC flag into __put_user() value evaluation

Pull SCSI fixes from James Bottomley:
 "Nine small fixes.

  The resume fix is a cosmetic removal of a warning with an incorrect
  condition causing it to alarm people wrongly.

  The other eight patches correct a thinko in Christoph Hellwig's DMA
  conversion series. Without it all these drivers end up with 32 bit DMA
  masks meaning they bounce any page over 4GB before sending it to the
  controller.

  Nowadays, even laptops mostly have memory above 4GB, so this can lead
  to significant performance degradation with all the bouncing"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  scsi: core: Avoid that system resume triggers a kernel warning
  scsi: hptiop: fix calls to dma_set_mask()
  scsi: hisi_sas: fix calls to dma_set_mask_and_coherent()
  scsi: csiostor: fix calls to dma_set_mask_and_coherent()
  scsi: bfa: fix calls to dma_set_mask_and_coherent()
  scsi: aic94xx: fix calls to dma_set_mask_and_coherent()
  scsi: 3w-sas: fix calls to dma_set_mask_and_coherent()
  scsi: 3w-9xxx: fix calls to dma_set_mask_and_coherent()
  scsi: lpfc: fix calls to dma_set_mask_and_coherent()

Pull networking fixes from David Miller:

 1) Fix refcount leak in act_ipt during replace, from Davide Caratti.

 2) Set task state properly in tun during blocking reads, from Timur
    Celik.

 3) Leaked reference in DSA, from Wen Yang.

 4) NULL deref in act_tunnel_key, from Vlad Buslov.

 5) cipso_v4_erro can reference the skb IPCB in inappropriate contexts
    thus referencing garbage, from Nazarov Sergey.

 6) Don't accept RTA_VIA and RTA_GATEWAY in contexts where those
    attributes make no sense.

 7) Fix hung sendto in tipc, from Tung Nguyen.

 8) Out-of-bounds access in netlabel, from Paul Moore.

 9) Grant reference leak in xen-netback, from Igor Druzhinin.

10) Fix tx stalls with lan743x, from Bryan Whitehead.

11) Fix interrupt storm with mv88e6xxx, from Hein Kallweit.

12) Memory leak in sit on device registry failure, from Mao Wenan.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (44 commits)
  net: sit: fix memory leak in sit_init_net()
  net: dsa: mv88e6xxx: Fix statistics on mv88e6161
  geneve: correctly handle ipv6.disable module parameter
  net: dsa: mv88e6xxx: prevent interrupt storm caused by mv88e6390x_port_set_cmode
  bpf: fix sanitation rewrite in case of non-pointers
  ipv4: Add ICMPv6 support when parse route ipproto
  MIPS: eBPF: Fix icache flush end address
  lan743x: Fix TX Stall Issue
  net: phy: phylink: fix uninitialized variable in phylink_get_mac_state
  net: aquantia: regression on cpus with high cores: set mode with 8 queues
  selftests: fixes for UDP GRO
  bpf: drop refcount if bpf_map_new_fd() fails in map_create()
  net: dsa: mv88e6xxx: power serdes on/off for 10G interfaces on 6390X
  net: dsa: mv88e6xxx: Fix u64 statistics
  xen-netback: don't populate the hash cache on XenBus disconnect
  xen-netback: fix occasional leak of grant ref mappings under memory pressure
  sctp: chunk.c: correct format string for size_t in printk
  net: netem: fix skb length BUG_ON in __skb_to_sgvec
  netlabel: fix out-of-bounds memory accesses
  ipv4: Pass original device to ip_rcv_finish_core
  ...

Pull more crypto fixes from Herbert Xu:
 "This fixes a couple of issues in arm64/chacha that was introduced in
  5.0"

* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
  crypto: arm64/chacha - fix hchacha_block_neon() for big endian
  crypto: arm64/chacha - fix chacha_4block_xor_neon() for big endian