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  1. 13 11月, 2018 11 次提交
    • P
      MAINTAINERS: Add Joel Fernandes as RCU reviewer · b430c588
      由 Paul E. McKenney 提交于 
      Signed-off-by: NPaul E. McKenney <paulmck@linux.ibm.com>
Reviewed-by: NJoel Fernandes <joel@joelfernandes.org>
      b430c588
    • P
      rcu: Avoid signed integer overflow in rcu_preempt_deferred_qs() · 5f1a6ef3
      由 Paul E. McKenney 提交于 
      Subtracting INT_MIN can be interpreted as unconditional signed integer
overflow, which according to the C standard is undefined behavior.
Therefore, kernel build arguments notwithstanding, it would be good to
future-proof the code.  This commit therefore substitutes INT_MAX for
INT_MIN in order to avoid undefined behavior.

While in the neighborhood, this commit also creates some meaningful names
for INT_MAX and friends in order to improve readability, as suggested
by Joel Fernandes.
Reported-by: NRan Rozenstein <ranro@mellanox.com>
Signed-off-by: NPaul E. McKenney <paulmck@linux.ibm.com>
      5f1a6ef3
    • P
      rcu: Replace this_cpu_ptr() with __this_cpu_read() · 117f683c
      由 Paul E. McKenney 提交于 
      Because __this_cpu_read() can be lighter weight than equivalent uses of
this_cpu_ptr(), this commit replaces the latter with the former.
Signed-off-by: NPaul E. McKenney <paulmck@linux.ibm.com>
      117f683c
    • P
      rcu: Speed up expedited GPs when interrupting RCU reader · 05f41571
      由 Paul E. McKenney 提交于 
      In PREEMPT kernels, an expedited grace period might send an IPI to a
CPU that is executing an RCU read-side critical section.  In that case,
it would be nice if the rcu_read_unlock() directly interacted with the
RCU core code to immediately report the quiescent state.  And this does
happen in the case where the reader has been preempted.  But it would
also be a nice performance optimization if immediate reporting also
happened in the preemption-free case.

This commit therefore adds an ->exp_hint field to the task_struct structure's
->rcu_read_unlock_special field.  The IPI handler sets this hint when
it has interrupted an RCU read-side critical section, and this causes
the outermost rcu_read_unlock() call to invoke rcu_read_unlock_special(),
which, if preemption is enabled, reports the quiescent state immediately.
If preemption is disabled, then the report is required to be deferred
until preemption (or bottom halves or interrupts or whatever) is re-enabled.

Because this is a hint, it does nothing for more complicated cases.  For
example, if the IPI interrupts an RCU reader, but interrupts are disabled
across the rcu_read_unlock(), but another rcu_read_lock() is executed
before interrupts are re-enabled, the hint will already have been cleared.
If you do crazy things like this, reporting will be deferred until some
later RCU_SOFTIRQ handler, context switch, cond_resched(), or similar.
Reported-by: NJoel Fernandes <joel@joelfernandes.org>
Signed-off-by: NPaul E. McKenney <paulmck@linux.ibm.com>
Acked-by: NJoel Fernandes (Google) <joel@joelfernandes.org>
      05f41571
    • P
      rcu: Trace end of grace period before end of grace period · 0a89e5a4
      由 Paul E. McKenney 提交于 
      Currently, rcu_gp_cleanup() traces the end of the old grace period after
the old grace period has officially ended.  This might make intuitive
sense, but it also makes for confusing event-trace output because the
"end" trace displays not the old but instead the new grace-period number.
This commit therefore traces the end of an old grace period just before
that grace period officially ends.
Reported-by: NAravinda Prasad <aravinda@linux.vnet.ibm.com>
Signed-off-by: NPaul E. McKenney <paulmck@linux.ibm.com>
      0a89e5a4
    • Z
      rcu: Adjust the comment of function rcu_is_watching · 2320bda2
      由 Zhouyi Zhou 提交于 
      Because RCU avoids interrupting idle CPUs, rcu_is_watching() is used to
test whether or not it is currently legal to run RCU read-side critical
sections on this CPU.  However, the first sentence and last sentences
of current comment for rcu_is_watching have opposite meaning of what
is expected.  This commit therefore fixes this header comment.
Signed-off-by: NZhouyi Zhou <zhouzhouyi@gmail.com>
Signed-off-by: NPaul E. McKenney <paulmck@linux.ibm.com>
      2320bda2
    • P
      rcu: Add jiffies-since-GP-activity to show_rcu_gp_kthreads() · c669c014
      由 Paul E. McKenney 提交于 
      This commit adds a printout of the number of jiffies since the last time
that the RCU grace-period kthread did any processing.  This can be useful
when tracking down forward-progress issues.
Signed-off-by: NPaul E. McKenney <paulmck@linux.ibm.com>
      c669c014
    • P
      rcu: Add state name to show_rcu_gp_kthreads() output · 69196019
      由 Paul E. McKenney 提交于 
      This commit adds the name of the RCU grace-period state to
the show_rcu_gp_kthreads() output in order to ease debugging.
This commit also moves gp_state_getname() up in the code so that
show_rcu_gp_kthreads() can use it.
Signed-off-by: NPaul E. McKenney <paulmck@linux.ibm.com>
      69196019
    • P
      rcu: Parameterize rcu_check_gp_start_stall() · 791416c4
      由 Paul E. McKenney 提交于 
      In order to debug forward-progress stalls, it is necessary to check
for excessively delayed grace-period starts.  This is currently done
for RCU CPU stall warnings by rcu_check_gp_start_stall(), which checks
to see if the start of a requested grace period has been delayed by an
RCU CPU stall warning period.  Because rcutorture will need to check
for the time consumed by an RCU forward-progress delay, this commit
promotes gpssdelay from a local variable to a formal parameter.  It is
not necessary to export rcu_check_gp_start_stall() because rcutorture
will access it via a wrapper function.
Signed-off-by: NPaul E. McKenney <paulmck@linux.ibm.com>
      791416c4
    • P
      rcu: Avoid double multiply by HZ · b3c1d9ec
      由 Paul E. McKenney 提交于 
      The rcu_check_gp_start_stall() function multiplies the return value
from rcu_jiffies_till_stall_check() by HZ, but the units are already
in jiffies.  This commit therefore avoids the need for introduction of
a jiffies-squared unit by removing the extraneous multiplication.
Signed-off-by: NPaul E. McKenney <paulmck@linux.ibm.com>
      b3c1d9ec
    • P
      MAINTAINERS: Update from @linux.vnet.ibm.com to @linux.ibm.com · 1dfddcdb
      由 Paul E. McKenney 提交于 
      IBM's patch-friendly email infrastructure is changing domains from
@linux.vnet.ibm.com to @linux.ibm.com, which if nothing else might
save a bit of typing.  This commit therefore updates us stragglers'
email addresses in the MAINTAINERS file.  The old addresses are
expected to continue to work for a few more months.

While in the neighborhood, remove some obsolete entries, which results
in an orphaned subsystem: "JSM Neo PCI based serial card".
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Douglas Miller <dougmill@linux.ibm.com>
Cc: Eddie James <eajames@linux.ibm.com>
Cc: Frank Haverkamp <haver@linux.ibm.com>
Cc: Frederic Barrat <fbarrat@linux.ibm.com>
Cc: John Allen <jallen@linux.ibm.com>
Cc: Manoj N. Kumar <manoj@linux.ibm.com>
Cc: Matthew R. Ochs <mrochs@linux.ibm.com>
Cc: Michael Cyr <mikecyr@linux.ibm.com>
Cc: Naveen N. Rao <naveen.n.rao@linux.ibm.com>
Cc: Paulo Flabiano Smorigo <pfsmorigo@linux.ibm.com>
Cc: Philip Kelleher <pjk1939@linux.ibm.com>
Cc: Steven Royer <seroyer@linux.ibm.com>
Cc: Thomas Falcon <tlfalcon@linux.ibm.com>
Cc: Tyrel Datwyler <tyreld@linux.ibm.com>
Cc: Uma Krishnan <ukrishn@linux.ibm.com>
Acked-by: NJames Bottomley <jejb@linux.ibm.com>
Acked-by: NMimi Zohar <zohar@linux.ibm.com>
      1dfddcdb
  3. 12 11月, 2018 1 次提交
    • P
      rcu: Stop expedited grace periods from relying on stop-machine · 9cac83a5
      由 Paul E. McKenney 提交于 
      The CPU-selection code in sync_rcu_exp_select_cpus() disables preemption
to prevent the cpu_online_mask from changing.  However, this relies on
the stop-machine mechanism in the CPU-hotplug offline code, which is not
desirable (it would be good to someday remove the stop-machine mechanism).

This commit therefore instead uses the relevant leaf rcu_node structure's
->ffmask, which has a bit set for all CPUs that are fully functional.
A given CPU's bit is cleared very early during offline processing by
rcutree_offline_cpu() and set very late during online processing by
rcutree_online_cpu().  Therefore, if a CPU's bit is set in this mask, and
preemption is disabled, we have to be before the synchronize_sched() in
the CPU-hotplug offline code, which means that the CPU is guaranteed to be
workqueue-ready throughout the duration of the enclosing preempt_disable()
region of code.

This also has the side-effect of using WORK_CPU_UNBOUND if all the CPUs for
this leaf rcu_node structure are offline, which is an acceptable difference
in behavior.
Reported-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
      9cac83a5
  5. 05 11月, 2018 5 次提交
    • L
      Linux 4.20-rc1 · 65102238
      由 Linus Torvalds 提交于
      65102238
    • L
      Merge tag 'tags/upstream-4.20-rc1' of git://git.infradead.org/linux-ubifs · 42bd06e9
      由 Linus Torvalds 提交于 
      Pull UBIFS updates from Richard Weinberger:

 - Full filesystem authentication feature, UBIFS is now able to have the
   whole filesystem structure authenticated plus user data encrypted and
   authenticated.

 - Minor cleanups

* tag 'tags/upstream-4.20-rc1' of git://git.infradead.org/linux-ubifs: (26 commits)
  ubifs: Remove unneeded semicolon
  Documentation: ubifs: Add authentication whitepaper
  ubifs: Enable authentication support
  ubifs: Do not update inode size in-place in authenticated mode
  ubifs: Add hashes and HMACs to default filesystem
  ubifs: authentication: Authenticate super block node
  ubifs: Create hash for default LPT
  ubfis: authentication: Authenticate master node
  ubifs: authentication: Authenticate LPT
  ubifs: Authenticate replayed journal
  ubifs: Add auth nodes to garbage collector journal head
  ubifs: Add authentication nodes to journal
  ubifs: authentication: Add hashes to index nodes
  ubifs: Add hashes to the tree node cache
  ubifs: Create functions to embed a HMAC in a node
  ubifs: Add helper functions for authentication support
  ubifs: Add separate functions to init/crc a node
  ubifs: Format changes for authentication support
  ubifs: Store read superblock node
  ubifs: Drop write_node
  ...
      42bd06e9
    • L
      Merge tag 'nfs-for-4.20-2' of git://git.linux-nfs.org/projects/trondmy/linux-nfs · 4710e789
      由 Linus Torvalds 提交于 
      Pull NFS client bugfixes from Trond Myklebust:
 "Highlights include:

  Bugfix:
   - Fix build issues on architectures that don't provide 64-bit cmpxchg

  Cleanups:
   - Fix a spelling mistake"

* tag 'nfs-for-4.20-2' of git://git.linux-nfs.org/projects/trondmy/linux-nfs:
  NFS: fix spelling mistake, EACCESS -> EACCES
  SUNRPC: Use atomic(64)_t for seq_send(64)
      4710e789
    • L
      Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip · 35e74524
      由 Linus Torvalds 提交于 
      Pull more timer updates from Thomas Gleixner:
 "A set of commits for the new C-SKY architecture timers"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  dt-bindings: timer: gx6605s SOC timer
  clocksource/drivers/c-sky: Add gx6605s SOC system timer
  dt-bindings: timer: C-SKY Multi-processor timer
  clocksource/drivers/c-sky: Add C-SKY SMP timer
      35e74524
    • L
      Merge tag 'ntb-4.20' of git://github.com/jonmason/ntb · 04578e84
      由 Linus Torvalds 提交于 
      Pull NTB updates from Jon Mason:
 "Fairly minor changes and bug fixes:

  NTB IDT thermal changes and hook into hwmon, ntb_netdev clean-up of
  private struct, and a few bug fixes"

* tag 'ntb-4.20' of git://github.com/jonmason/ntb:
  ntb: idt: Alter the driver info comments
  ntb: idt: Discard temperature sensor IRQ handler
  ntb: idt: Add basic hwmon sysfs interface
  ntb: idt: Alter temperature read method
  ntb_netdev: Simplify remove with client device drvdata
  NTB: transport: Try harder to alloc an aligned MW buffer
  ntb: ntb_transport: Mark expected switch fall-throughs
  ntb: idt: Set PCIe bus address to BARLIMITx
  NTB: ntb_hw_idt: replace IS_ERR_OR_NULL with regular NULL checks
  ntb: intel: fix return value for ndev_vec_mask()
  ntb_netdev: fix sleep time mismatch
      04578e84
  7. 04 11月, 2018 23 次提交