1. 17 Aug, 2017 1 commit
    • Mathieu Desnoyers's avatar
      membarrier: Provide expedited private command · 22e4ebb9
      Mathieu Desnoyers authored
      Implement MEMBARRIER_CMD_PRIVATE_EXPEDITED with IPIs using cpumask built
      from all runqueues for which current thread's mm is the same as the
      thread calling sys_membarrier. It executes faster than the non-expedited
      variant (no blocking). It also works on NOHZ_FULL configurations.
      
      Scheduler-wise, it requires a memory barrier before and after context
      switching between processes (which have different mm). The memory
      barrier before context switch is already present. For the barrier after
      context switch:
      
      * Our TSO archs can do RELEASE without being a full barrier. Look at
        x86 spin_unlock() being a regular STORE for example.  But for those
        archs, all atomics imply smp_mb and all of them have atomic ops in
        switch_mm() for mm_cpumask(), and on x86 the CR3 load acts as a full
        barrier.
      
      * From all weakly ordered machines, only ARM64 and PPC can do RELEASE,
        the rest does indeed do smp_mb(), so there the spin_unlock() is a full
        barrier and we're good.
      
      * ARM64 has a very heavy barrier in switch_to(), which suffices.
      
      * PPC just removed its barrier from switch_to(), but appears to be
        talking about adding something to switch_mm(). So add a
        smp_mb__after_unlock_lock() for now, until this is settled on the PPC
        side.
      
      Changes since v3:
      - Properly document the memory barriers provided by each architecture.
      
      Changes since v2:
      - Address comments from Peter Zijlstra,
      - Add smp_mb__after_unlock_lock() after finish_lock_switch() in
        finish_task_switch() to add the memory barrier we need after storing
        to rq->curr. This is much simpler than the previous approach relying
        on atomic_dec_and_test() in mmdrop(), which actually added a memory
        barrier in the common case of switching between userspace processes.
      - Return -EINVAL when MEMBARRIER_CMD_SHARED is used on a nohz_full
        kernel, rather than having the whole membarrier system call returning
        -ENOSYS. Indeed, CMD_PRIVATE_EXPEDITED is compatible with nohz_full.
        Adapt the CMD_QUERY mask accordingly.
      
      Changes since v1:
      - move membarrier code under kernel/sched/ because it uses the
        scheduler runqueue,
      - only add the barrier when we switch from a kernel thread. The case
        where we switch from a user-space thread is already handled by
        the atomic_dec_and_test() in mmdrop().
      - add a comment to mmdrop() documenting the requirement on the implicit
        memory barrier.
      
      CC: Peter Zijlstra <peterz@infradead.org>
      CC: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
      CC: Boqun Feng <boqun.feng@gmail.com>
      CC: Andrew Hunter <ahh@google.com>
      CC: Maged Michael <maged.michael@gmail.com>
      CC: gromer@google.com
      CC: Avi Kivity <avi@scylladb.com>
      CC: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      CC: Paul Mackerras <paulus@samba.org>
      CC: Michael Ellerman <mpe@ellerman.id.au>
      Signed-off-by: default avatarMathieu Desnoyers <mathieu.desnoyers@efficios.com>
      Signed-off-by: default avatarPaul E. McKenney <paulmck@linux.vnet.ibm.com>
      Tested-by: default avatarDave Watson <davejwatson@fb.com>
      22e4ebb9
  2. 28 Jul, 2017 1 commit
    • Tejun Heo's avatar
      sched: Allow migrating kthreads into online but inactive CPUs · 955dbdf4
      Tejun Heo authored
      Per-cpu workqueues have been tripping CPU affinity sanity checks while
      a CPU is being offlined.  A per-cpu kworker ends up running on a CPU
      which isn't its target CPU while the CPU is online but inactive.
      
      While the scheduler allows kthreads to wake up on an online but
      inactive CPU, it doesn't allow a running kthread to be migrated to
      such a CPU, which leads to an odd situation where setting affinity on
      a sleeping and running kthread leads to different results.
      
      Each mem-reclaim workqueue has one rescuer which guarantees forward
      progress and the rescuer needs to bind itself to the CPU which needs
      help in making forward progress; however, due to the above issue,
      while set_cpus_allowed_ptr() succeeds, the rescuer doesn't end up on
      the correct CPU if the CPU is in the process of going offline,
      tripping the sanity check and executing the work item on the wrong
      CPU.
      
      This patch updates __migrate_task() so that kthreads can be migrated
      into an inactive but online CPU.
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      Reported-by: default avatar"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
      Reported-by: default avatarSteven Rostedt <rostedt@goodmis.org>
      Signed-off-by: default avatarPaul E. McKenney <paulmck@linux.vnet.ibm.com>
      955dbdf4
  3. 24 Jul, 2017 2 commits
  4. 23 Jul, 2017 8 commits
  5. 22 Jul, 2017 6 commits
    • Linus Torvalds's avatar
      Merge tag 'hwmon-for-linus-v4.13-rc2' of... · 4b162c53
      Linus Torvalds authored
      Merge tag 'hwmon-for-linus-v4.13-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging
      
      Pull hwmon fix from Guenter Roeck:
       "Avoid buffer overruns in applesmc driver"
      
      * tag 'hwmon-for-linus-v4.13-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging:
        hwmon: (applesmc) Avoid buffer overruns
      4b162c53
    • Linus Torvalds's avatar
      Merge tag 'tty-4.13-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty · ae75d1ae
      Linus Torvalds authored
      Pull tty/serial fixes from Greg KH:
       "Here are some small tty and serial driver fixes for 4.13-rc2. Nothing
        huge at all, a revert of a patch that turned out to break things, a
        fix up for a new tty ioctl we added in 4.13-rc1 to get the uapi
        definition correct, and a few minor serial driver fixes for reported
        issues.
      
        All of these have been in linux-next for a while with no reported
        issues"
      
      * tag 'tty-4.13-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
        tty: Fix TIOCGPTPEER ioctl definition
        tty: hide unused pty_get_peer function
        tty: serial: lpuart: Fix the logic for detecting the 32-bit type UART
        serial: imx: Prevent TX buffer PIO write when a DMA has been started
        Revert "serial: imx-serial - move DMA buffer configuration to DT"
        serial: sh-sci: Uninitialized variables in sysfs files
        serial: st-asc: Potential error pointer dereference
      ae75d1ae
    • Linus Torvalds's avatar
      Merge tag 'char-misc-4.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc · dedaff2f
      Linus Torvalds authored
      Pull char/misc driver fixes from Greg KH:
       "Here are some small char and misc driver fixes for 4.13-rc2. All fix
        reported problems with 4.13-rc1 or older kernels (like the binder
        fixes). Full details in the shortlog.
      
        All have been in linux-next with no reported issues"
      
      * tag 'char-misc-4.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
        w1: omap-hdq: fix error return code in omap_hdq_probe()
        regmap: regmap-w1: Fix build troubles
        w1: Fix slave count on 1-Wire bus (resend)
        mux: mux-core: unregister mux_class in mux_exit()
        mux: remove the Kconfig question for the subsystem
        nvmem: rockchip-efuse: amend compatible rk322x-efuse to rk3228-efuse
        drivers/fsi: fix fsi_slave_mode prototype
        fsi: core: register with postcore_initcall
        thunderbolt: Correct access permissions for active NVM contents
        vmbus: re-enable channel tasklet
        spmi: pmic-arb: Always allocate ppid_to_apid table
        MAINTAINERS: Add entry for SPMI subsystem
        spmi: Include OF based modalias in device uevent
        binder: Use wake up hint for synchronous transactions.
        binder: use group leader instead of open thread
        Revert "android: binder: Sanity check at binder ioctl"
      dedaff2f
    • Linus Torvalds's avatar
      Merge tag 'usb-4.13-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb · 55fd939e
      Linus Torvalds authored
      Pull USB fixes from Greg KH:
       "Here are some small USB fixes for 4.13-rc2.
      
        The usual batch, gadget fixes for reported issues, as well as xhci
        fixes, and a small random collection of other fixes for reported
        issues.
      
        All have been in linux-next with no reported issues"
      
      * tag 'usb-4.13-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb: (25 commits)
        xhci: fix memleak in xhci_run()
        usb: xhci: fix spinlock recursion for USB2 test mode
        xhci: fix 20000ms port resume timeout
        usb: xhci: Issue stop EP command only when the EP state is running
        xhci: Bad Ethernet performance plugged in ASM1042A host
        xhci: Fix NULL pointer dereference when cleaning up streams for removed host
        usb: renesas_usbhs: gadget: disable all eps when the driver stops
        usb: renesas_usbhs: fix usbhsc_resume() for !USBHSF_RUNTIME_PWCTRL
        usb: gadget: udc: renesas_usb3: protect usb3_ep->started in usb3_start_pipen()
        usb: gadget: udc: renesas_usb3: fix zlp transfer by the dmac
        usb: gadget: udc: renesas_usb3: fix free size in renesas_usb3_dma_free_prd()
        usb: gadget: f_uac2: endianness fixes.
        usb: gadget: f_uac1: endianness fixes.
        include: usb: audio: specify exact endiannes of descriptors
        usb: gadget: udc: start_udc() can be static
        usb: dwc2: gadget: On USB RESET reset device address to zero
        usb: storage: return on error to avoid a null pointer dereference
        usb: typec: include linux/device.h in ucsi.h
        USB: cdc-acm: add device-id for quirky printer
        usb: dwc3: gadget: only unmap requests from DMA if mapped
        ...
      55fd939e
    • Linus Torvalds's avatar
      Merge tag 'staging-4.13-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging · bcb53e57
      Linus Torvalds authored
      Pull staging driver fixes from Greg KH:
       "Here are some small staging driver fixes for reported issues for
        4.13-rc2.
      
        Also in here is a new driver, the virtualbox DRM driver. It's
        stand-alone and got acks from the DRM developers to go in through this
        tree. It's a new thing, but it should be fine for this point in the rc
        cycle due to it being independent.
      
        All of this has been in linux-next for a while with no reported
        issues"
      
      * tag 'staging-4.13-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging:
        staging: rtl8188eu: add TL-WN722N v2 support
        staging: speakup: safely register and unregister ldisc
        staging: speakup: add functions to register and unregister ldisc
        staging: speakup: safely close tty
        staging: sm750fb: avoid conflicting vesafb
        staging: lustre: ko2iblnd: check copy_from_iter/copy_to_iter return code
        staging: vboxvideo: Add vboxvideo to drivers/staging
        staging: sm750fb: fixed a assignment typo
        staging: rtl8188eu: memory leak in rtw_free_cmd_obj()
        staging: vchiq_arm: fix error codes in probe
        staging: comedi: ni_mio_common: fix AO timer off-by-one regression
      bcb53e57
    • Randy Dunlap's avatar
      MAINTAINERS: fix alphabetical ordering · 82abbea7
      Randy Dunlap authored
      Fix major alphabetic errors.  No attempt to fix items that all begin
      with the same word (like ARM, BROADCOM, DRM, EDAC, FREESCALE, INTEL,
      OMAP, PCI, SAMSUNG, TI, USB, etc.).
      
      (diffstat +/- is different by one line because TI KEYSTONE MULTICORE
      had 2 blank lines after it.)
      Signed-off-by: default avatarRandy Dunlap <rdunlap@infradead.org>
      Acked-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      82abbea7
  6. 21 Jul, 2017 22 commits