1. 16 Nov, 2012 4 commits
    • Paul E. McKenney's avatar
      rcu: Add callback-free CPUs · 3fbfbf7a
      Paul E. McKenney authored
      RCU callback execution can add significant OS jitter and also can
      degrade both scheduling latency and, in asymmetric multiprocessors,
      energy efficiency.  This commit therefore adds the ability for selected
      CPUs ("rcu_nocbs=" boot parameter) to have their callbacks offloaded
      to kthreads.  If the "rcu_nocb_poll" boot parameter is also specified,
      these kthreads will do polling, removing the need for the offloaded
      CPUs to do wakeups.  At least one CPU must be doing normal callback
      processing: currently CPU 0 cannot be selected as a no-CBs CPU.
      In addition, attempts to offline the last normal-CBs CPU will fail.
      
      This feature was inspired by Jim Houston's and Joe Korty's JRCU, and
      this commit includes fixes to problems located by Fengguang Wu's
      kbuild test robot.
      
      [ paulmck: Added gfp.h include file as suggested by Fengguang Wu. ]
      Signed-off-by: default avatarPaul E. McKenney <paul.mckenney@linaro.org>
      Signed-off-by: default avatarPaul E. McKenney <paulmck@linux.vnet.ibm.com>
      3fbfbf7a
    • Paul E. McKenney's avatar
      Merge branches 'urgent.2012.10.27a', 'doc.2012.11.16a', 'fixes.2012.11.13a',... · aac1cda3
      Paul E. McKenney authored
      Merge branches 'urgent.2012.10.27a', 'doc.2012.11.16a', 'fixes.2012.11.13a', 'srcu.2012.10.27a', 'stall.2012.11.13a', 'tracing.2012.11.08a' and 'idle.2012.10.24a' into HEAD
      
      urgent.2012.10.27a: Fix for RCU user-mode transition (already in -tip).
      
      doc.2012.11.08a: Documentation updates, most notably codifying the
      	memory-barrier guarantees inherent to grace periods.
      
      fixes.2012.11.13a: Miscellaneous fixes.
      
      srcu.2012.10.27a: Allow statically allocated and initialized srcu_struct
      	structures (courtesy of Lai Jiangshan).
      
      stall.2012.11.13a: Add more diagnostic information to RCU CPU stall
      	warnings, also decrease from 60 seconds to 21 seconds.
      
      hotplug.2012.11.08a: Minor updates to CPU hotplug handling.
      
      tracing.2012.11.08a: Improved debugfs tracing, courtesy of Michael Wang.
      
      idle.2012.10.24a: Updates to RCU idle/adaptive-idle handling, including
      	a boot parameter that maps normal grace periods to expedited.
      
      Resolved conflict in kernel/rcutree.c due to side-by-side change.
      aac1cda3
    • Paul E. McKenney's avatar
      rcu: Add documentation for the new rcuexp debugfs trace file · d484a215
      Paul E. McKenney authored
      This commit adds the documentation of the rcuexp debugfs trace file
      that records statistics for expedited grace periods.
      Signed-off-by: default avatarPaul E. McKenney <paul.mckenney@linaro.org>
      Signed-off-by: default avatarPaul E. McKenney <paulmck@linux.vnet.ibm.com>
      d484a215
    • Paul E. McKenney's avatar
      rcu: Update documentation for TREE_RCU debugfs tracing · 40e80c46
      Paul E. McKenney authored
      This commit updates the tracing documentation to reflect the new
      format that has per-RCU-flavor directories.
      Signed-off-by: default avatarPaul E. McKenney <paul.mckenney@linaro.org>
      Signed-off-by: default avatarPaul E. McKenney <paulmck@linux.vnet.ibm.com>
      40e80c46
  2. 13 Nov, 2012 6 commits
  3. 08 Nov, 2012 20 commits
  4. 27 Oct, 2012 3 commits
  5. 24 Oct, 2012 1 commit
  6. 23 Oct, 2012 6 commits