Skip to content

L
linux
Switch branch/tag
  1. 18 Mar, 2011 36 commits
  3. 17 Mar, 2011 4 commits
    • Linus Torvalds's avatar
      Merge branch 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/staging · 19520fc1
      Linus Torvalds authored 
      * 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/staging: (44 commits)
  hwmon: (lineage-pem): Fix in1 voltage alarm sysfs attributes
  hwmon/f71882fg: Add support for f71808e
  hwmon/f71882fg: Add support for f71869f and f71869e
  hwmon/f71882fg: Add support for f71889ed
  hwmon/f71882fg: Break out test for auto pwm's controlled by digital readings
  hwmon/f71882fg: Separate temp beep sysfs attr from the other temp sysfs attr
  hwmon/f71882fg: Remove bogus temp2_type for certain models
  hwmon/f71882fg: Make number of temps configurable
  hwmon/f71882fg: Make creation of in sysfs attributes more generic
  hwmon/f71882fg: Only allow negative auto point temps if fan_neg_temp is enabled
  hwmon/f71882fg: Fix temp1 sensor type reporting
  hwmon: (w83627ehf) Display correct temperature sensor labels for systems with NCT6775F
  hwmon: (w83627ehf) Add fan debounce support for NCT6775F and NCT6776F
  hwmon: (w83627ehf) Update Kconfig for W83677HG-B, NCT6775F and NCT6776F
  hwmon: (w83627ehf) Store rpm instead of raw fan speed data
  hwmon: (w83627ehf) Use 16 bit fan count registers if supported
  hwmon: (w83627ehf) Add support for Nuvoton NCT6775F and NCT6776F
  hwmon: (w83627ehf) Permit enabling SmartFan IV mode if configured at startup
  hwmon: (w83627ehf) Convert register arrays to 16 bit, and convert access to pointers
  hwmon: (w83627ehf) Remove references to datasheets which no longer exist
  ...
      19520fc1
    • Milton Miller's avatar
      smp_call_function_interrupt: use typedef and %pf · c8def554
      Milton Miller authored 
      Use the newly added smp_call_func_t in smp_call_function_interrupt for
the func variable, and make the comment above the WARN more assertive
and explicit.  Also, func is a function pointer and does not need an
offset, so use %pf not %pS.
Signed-off-by: default avatarMilton Miller <miltonm@bga.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      c8def554
    • Milton Miller's avatar
      smp_call_function_many: handle concurrent clearing of mask · 723aae25
      Milton Miller authored 
      Mike Galbraith reported finding a lockup ("perma-spin bug") where the
cpumask passed to smp_call_function_many was cleared by other cpu(s)
while a cpu was preparing its call_data block, resulting in no cpu to
clear the last ref and unlock the block.

Having cpus clear their bit asynchronously could be useful on a mask of
cpus that might have a translation context, or cpus that need a push to
complete an rcu window.

Instead of adding a BUG_ON and requiring yet another cpumask copy, just
detect the race and handle it.

Note: arch_send_call_function_ipi_mask must still handle an empty
cpumask because the data block is globally visible before the that arch
callback is made.  And (obviously) there are no guarantees to which cpus
are notified if the mask is changed during the call; only cpus that were
online and had their mask bit set during the whole call are guaranteed
to be called.
Reported-by: default avatarMike Galbraith <efault@gmx.de>
Reported-by: default avatarJan Beulich <JBeulich@novell.com>
Acked-by: default avatarJan Beulich <jbeulich@novell.com>
Cc: stable@kernel.org
Signed-off-by: default avatarMilton Miller <miltonm@bga.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      723aae25
    • Milton Miller's avatar
      call_function_many: add missing ordering · 45a57919
      Milton Miller authored 
      Paul McKenney's review pointed out two problems with the barriers in the
2.6.38 update to the smp call function many code.

First, a barrier that would force the func and info members of data to
be visible before their consumption in the interrupt handler was
missing.  This can be solved by adding a smp_wmb between setting the
func and info members and setting setting the cpumask; this will pair
with the existing and required smp_rmb ordering the cpumask read before
the read of refs.  This placement avoids the need a second smp_rmb in
the interrupt handler which would be executed on each of the N cpus
executing the call request.  (I was thinking this barrier was present
but was not).

Second, the previous write to refs (establishing the zero that we the
interrupt handler was testing from all cpus) was performed by a third
party cpu.  This would invoke transitivity which, as a recient or
concurrent addition to memory-barriers.txt now explicitly states, would
require a full smp_mb().

However, we know the cpumask will only be set by one cpu (the data
owner) and any preivous iteration of the mask would have cleared by the
reading cpu.  By redundantly writing refs to 0 on the owning cpu before
the smp_wmb, the write to refs will follow the same path as the writes
that set the cpumask, which in turn allows us to keep the barrier in the
interrupt handler a smp_rmb instead of promoting it to a smp_mb (which
will be be executed by N cpus for each of the possible M elements on the
list).

I moved and expanded the comment about our (ab)use of the rcu list
primitives for the concurrent walk earlier into this function.  I
considered moving the first two paragraphs to the queue list head and
lock, but felt it would have been too disconected from the code.

Cc: Paul McKinney <paulmck@linux.vnet.ibm.com>
Cc: stable@kernel.org (2.6.32 and later)
Signed-off-by: default avatarMilton Miller <miltonm@bga.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      45a57919
GitLab Nexedi Edition | About GitLab | About Nexedi | 沪ICP备2021021310号-2 | 沪ICP备2021021310号-7