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  1. 29 Jan, 2018 28 commits
  3. 28 Jan, 2018 8 commits
  5. 27 Jan, 2018 2 commits
    • Thomas Gleixner's avatar
      hrtimer: Reset hrtimer cpu base proper on CPU hotplug · d5421ea4
      Thomas Gleixner authored 
      The hrtimer interrupt code contains a hang detection and mitigation
mechanism, which prevents that a long delayed hrtimer interrupt causes a
continous retriggering of interrupts which prevent the system from making
progress. If a hang is detected then the timer hardware is programmed with
a certain delay into the future and a flag is set in the hrtimer cpu base
which prevents newly enqueued timers from reprogramming the timer hardware
prior to the chosen delay. The subsequent hrtimer interrupt after the delay
clears the flag and resumes normal operation.

If such a hang happens in the last hrtimer interrupt before a CPU is
unplugged then the hang_detected flag is set and stays that way when the
CPU is plugged in again. At that point the timer hardware is not armed and
it cannot be armed because the hang_detected flag is still active, so
nothing clears that flag. As a consequence the CPU does not receive hrtimer
interrupts and no timers expire on that CPU which results in RCU stalls and
other malfunctions.

Clear the flag along with some other less critical members of the hrtimer
cpu base to ensure starting from a clean state when a CPU is plugged in.

Thanks to Paul, Sebastian and Anna-Maria for their help to get down to the
root cause of that hard to reproduce heisenbug. Once understood it's
trivial and certainly justifies a brown paperbag.

Fixes: 41d2e494 ("hrtimer: Tune hrtimer_interrupt hang logic")
Reported-by: default avatarPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Sewior <bigeasy@linutronix.de>
Cc: Anna-Maria Gleixner <anna-maria@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/alpine.DEB.2.20.1801261447590.2067@nanos
      d5421ea4
    • H. Peter Anvin's avatar
      x86: Mark hpa as a "Designated Reviewer" for the time being · 8a95b74d
      H. Peter Anvin authored 
      Due to some unfortunate events, I have not been directly involved in
the x86 kernel patch flow for a while now.  I have also not been able
to ramp back up by now like I had hoped to, and after reviewing what I
will need to work on both internally at Intel and elsewhere in the near
term, it is clear that I am not going to be able to ramp back up until
late 2018 at the very earliest.

It is not acceptable to not recognize that this load is currently
taken by Ingo and Thomas without my direct participation, so I mark
myself as R: (designated reviewer) rather than M: (maintainer) until
further notice.  This is in fact recognizing the de facto situation
for the past few years.

I have obviously no intention of going away, and I will do everything
within my power to improve Linux on x86 and x86 for Linux.  This,
however, puts credit where it is due and reflects a change of focus.

This patch also removes stale entries for portions of the x86
architecture which have not been maintained separately from arch/x86
for a long time.  If there is a reason to re-introduce them then that
can happen later.
Signed-off-by: default avatarH. Peter Anvin <h.peter.anvin@intel.com>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Cc: Bruce Schlobohm <bruce.schlobohm@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20180125195934.5253-1-hpa@zytor.comSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
      8a95b74d
  7. 26 Jan, 2018 2 commits
    • Linus Torvalds's avatar
      Merge tag 'riscv-for-linus-4.15-maintainers' of... · c4e0ca7f
      Linus Torvalds authored 
      Merge tag 'riscv-for-linus-4.15-maintainers' of git://git.kernel.org/pub/scm/linux/kernel/git/palmer/riscv-linux

Pull RISC-V update from Palmer Dabbelt:
 "RISC-V: We have a new mailing list and git repo!

  Sorry to send something essentially as late as possible (Friday after
  an rc9), but we managed to get a mailing list for the RISC-V Linux
  port. We've been using patches@groups.riscv.org for a while, but that
  list has some problems (it's Google Groups and it's shared over all
  RISC-V software projects). The new infaread.org list is much better.
  We just got it on Wednesday but I used it a bit on Thursday to shake
  out all the configuration problems and it appears to be in working
  order.

  When I updated the mailing list I noticed that the MAINTAINERS file
  was pointing to our github repo, but now that we have a kernel.org
  repo I'd like to point to that instead so I changed that as well.
  We'll be centralizing all RISC-V Linux related development here as
  that seems to be the saner way to go about it.

  I can understand if it's too late to get this into 4.15, but given
  that it's not a code change I was hoping it'd still be OK. It would be
  nice to have the new mailing list and git repo in the release tarballs
  so when people start to find bugs they'll get to the right place"

* tag 'riscv-for-linus-4.15-maintainers' of git://git.kernel.org/pub/scm/linux/kernel/git/palmer/riscv-linux:
  Update the RISC-V MAINTAINERS file
      c4e0ca7f
    • Linus Torvalds's avatar
      Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net · ba804bb4
      Linus Torvalds authored 
      Pull networking fixes from David Miller:

 1) The per-network-namespace loopback device, and thus its namespace,
    can have its teardown deferred for a long time if a kernel created
    TCP socket closes and the namespace is exiting meanwhile. The kernel
    keeps trying to finish the close sequence until it times out (which
    takes quite some time).

    Fix this by forcing the socket closed in this situation, from Dan
    Streetman.

 2) Fix regression where we're trying to invoke the update_pmtu method
    on route types (in this case metadata tunnel routes) that don't
    implement the dst_ops method. Fix from Nicolas Dichtel.

 3) Fix long standing memory corruption issues in r8169 driver by
    performing the chip statistics DMA programming more correctly. From
    Francois Romieu.

 4) Handle local broadcast sends over VRF routes properly, from David
    Ahern.

 5) Don't refire the DCCP CCID2 timer endlessly, otherwise the socket
    can never be released. From Alexey Kodanev.

 6) Set poll flags properly in VSOCK protocol layer, from Stefan
    Hajnoczi.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net:
  VSOCK: set POLLOUT | POLLWRNORM for TCP_CLOSING
  dccp: don't restart ccid2_hc_tx_rto_expire() if sk in closed state
  net: vrf: Add support for sends to local broadcast address
  r8169: fix memory corruption on retrieval of hardware statistics.
  net: don't call update_pmtu unconditionally
  net: tcp: close sock if net namespace is exiting
      ba804bb4
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