1. 21 4月, 2013 1 次提交
    • V
      sched: Fix wrong rq's runnable_avg update with rt tasks · 642dbc39
      Vincent Guittot 提交于
      The current update of the rq's load can be erroneous when RT
      tasks are involved.
      
      The update of the load of a rq that becomes idle, is done only
      if the avg_idle is less than sysctl_sched_migration_cost. If RT
      tasks and short idle duration alternate, the runnable_avg will
      not be updated correctly and the time will be accounted as idle
      time when a CFS task wakes up.
      
      A new idle_enter function is called when the next task is the
      idle function so the elapsed time will be accounted as run time
      in the load of the rq, whatever the average idle time is. The
      function update_rq_runnable_avg is removed from idle_balance.
      
      When a RT task is scheduled on an idle CPU, the update of the
      rq's load is not done when the rq exit idle state because CFS's
      functions are not called. Then, the idle_balance, which is
      called just before entering the idle function, updates the rq's
      load and makes the assumption that the elapsed time since the
      last update, was only running time.
      
      As a consequence, the rq's load of a CPU that only runs a
      periodic RT task, is close to LOAD_AVG_MAX whatever the running
      duration of the RT task is.
      
      A new idle_exit function is called when the prev task is the
      idle function so the elapsed time will be accounted as idle time
      in the rq's load.
      Signed-off-by: NVincent Guittot <vincent.guittot@linaro.org>
      Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
      Acked-by: NSteven Rostedt <rostedt@goodmis.org>
      Cc: linaro-kernel@lists.linaro.org
      Cc: peterz@infradead.org
      Cc: pjt@google.com
      Cc: fweisbec@gmail.com
      Cc: efault@gmx.de
      Link: http://lkml.kernel.org/r/1366302867-5055-1-git-send-email-vincent.guittot@linaro.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>
      642dbc39
  2. 10 4月, 2013 1 次提交
  3. 11 3月, 2013 1 次提交
  4. 06 3月, 2013 6 次提交
  5. 08 2月, 2013 2 次提交
  6. 11 12月, 2012 2 次提交
  7. 24 10月, 2012 9 次提交
  8. 13 9月, 2012 1 次提交
  9. 04 9月, 2012 1 次提交
  10. 20 8月, 2012 1 次提交
    • F
      sched: Move cputime code to its own file · 73fbec60
      Frederic Weisbecker 提交于
      Extract cputime code from the giant sched/core.c and
      put it in its own file. This make it easier to deal with
      this particular area and de-bloat a bit more core.c
      Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
      Acked-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
      Cc: Tony Luck <tony.luck@intel.com>
      Cc: Fenghua Yu <fenghua.yu@intel.com>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Cc: Ingo Molnar <mingo@kernel.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Peter Zijlstra <peterz@infradead.org>
      73fbec60
  11. 14 8月, 2012 2 次提交
  12. 24 7月, 2012 1 次提交
  13. 06 7月, 2012 1 次提交
  14. 06 6月, 2012 1 次提交
  15. 14 5月, 2012 1 次提交
    • P
      sched/nohz: Fix rq->cpu_load[] calculations · 556061b0
      Peter Zijlstra 提交于
      While investigating why the load-balancer did funny I found that the
      rq->cpu_load[] tables were completely screwy.. a bit more digging
      revealed that the updates that got through were missing ticks followed
      by a catchup of 2 ticks.
      
      The catchup assumes the cpu was idle during that time (since only nohz
      can cause missed ticks and the machine is idle etc..) this means that
      esp. the higher indices were significantly lower than they ought to
      be.
      
      The reason for this is that its not correct to compare against jiffies
      on every jiffy on any other cpu than the cpu that updates jiffies.
      
      This patch cludges around it by only doing the catch-up stuff from
      nohz_idle_balance() and doing the regular stuff unconditionally from
      the tick.
      Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: pjt@google.com
      Cc: Venkatesh Pallipadi <venki@google.com>
      Link: http://lkml.kernel.org/n/tip-tp4kj18xdd5aj4vvj0qg55s2@git.kernel.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>
      556061b0
  16. 09 5月, 2012 1 次提交
  17. 13 3月, 2012 1 次提交
  18. 01 3月, 2012 1 次提交
  19. 24 2月, 2012 1 次提交
    • I
      static keys: Introduce 'struct static_key', static_key_true()/false() and... · c5905afb
      Ingo Molnar 提交于
      static keys: Introduce 'struct static_key', static_key_true()/false() and static_key_slow_[inc|dec]()
      
      So here's a boot tested patch on top of Jason's series that does
      all the cleanups I talked about and turns jump labels into a
      more intuitive to use facility. It should also address the
      various misconceptions and confusions that surround jump labels.
      
      Typical usage scenarios:
      
              #include <linux/static_key.h>
      
              struct static_key key = STATIC_KEY_INIT_TRUE;
      
              if (static_key_false(&key))
                      do unlikely code
              else
                      do likely code
      
      Or:
      
              if (static_key_true(&key))
                      do likely code
              else
                      do unlikely code
      
      The static key is modified via:
      
              static_key_slow_inc(&key);
              ...
              static_key_slow_dec(&key);
      
      The 'slow' prefix makes it abundantly clear that this is an
      expensive operation.
      
      I've updated all in-kernel code to use this everywhere. Note
      that I (intentionally) have not pushed through the rename
      blindly through to the lowest levels: the actual jump-label
      patching arch facility should be named like that, so we want to
      decouple jump labels from the static-key facility a bit.
      
      On non-jump-label enabled architectures static keys default to
      likely()/unlikely() branches.
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      Acked-by: NJason Baron <jbaron@redhat.com>
      Acked-by: NSteven Rostedt <rostedt@goodmis.org>
      Cc: a.p.zijlstra@chello.nl
      Cc: mathieu.desnoyers@efficios.com
      Cc: davem@davemloft.net
      Cc: ddaney.cavm@gmail.com
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Link: http://lkml.kernel.org/r/20120222085809.GA26397@elte.huSigned-off-by: NIngo Molnar <mingo@elte.hu>
      c5905afb
  20. 22 2月, 2012 1 次提交
  21. 27 1月, 2012 1 次提交
  22. 21 12月, 2011 1 次提交
  23. 07 12月, 2011 2 次提交