1. 26 3月, 2008 1 次提交
    • T
      NOHZ: reevaluate idle sleep length after add_timer_on() · 06d8308c
      Thomas Gleixner 提交于
      add_timer_on() can add a timer on a CPU which is currently in a long
      idle sleep, but the timer wheel is not reevaluated by the nohz code on
      that CPU. So a timer can be delayed for quite a long time. This
      triggered a false positive in the clocksource watchdog code.
      
      To avoid this we need to wake up the idle CPU and enforce the
      reevaluation of the timer wheel for the next timer event.
      
      Add a function, which checks a given CPU for idle state, marks the
      idle task with NEED_RESCHED and sends a reschedule IPI to notify the
      other CPU of the change in the timer wheel.
      
      Call this function from add_timer_on().
      Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
      Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
      Acked-by: NIngo Molnar <mingo@elte.hu>
      Cc: stable@kernel.org
      
      --
       include/linux/sched.h |    6 ++++++
       kernel/sched.c        |   43 +++++++++++++++++++++++++++++++++++++++++++
       kernel/timer.c        |   10 +++++++++-
       3 files changed, 58 insertions(+), 1 deletion(-)
      06d8308c
  2. 25 3月, 2008 4 次提交
  3. 23 3月, 2008 1 次提交
  4. 21 3月, 2008 3 次提交
  5. 20 3月, 2008 3 次提交
    • A
      memstick: automatically retrieve "INT" value from command response · ead70773
      Alex Dubov 提交于
      MemoryStick storage cards, when in parallel mode, send several meaningful bits
      of their "INT" register as part of command response.  This data is stored by
      host and can be used to spare invocation of "GET_INT" TPC on each data page
      transferred between host and card.
      Signed-off-by: NAlex Dubov <oakad@yahoo.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      ead70773
    • R
      fs: fix kernel-doc notation warnings · a6b91919
      Randy Dunlap 提交于
      Fix kernel-doc notation warnings in fs/.
      
      Warning(mmotm-2008-0314-1449//fs/super.c:560): missing initial short description on line:
       *	mark_files_ro
      Warning(mmotm-2008-0314-1449//fs/locks.c:1277): missing initial short description on line:
       *	lease_get_mtime
      Warning(mmotm-2008-0314-1449//fs/locks.c:1277): missing initial short description on line:
       *	lease_get_mtime
      Warning(mmotm-2008-0314-1449//fs/namei.c:1368): missing initial short description on line:
       * lookup_one_len:  filesystem helper to lookup single pathname component
      Warning(mmotm-2008-0314-1449//fs/buffer.c:3221): missing initial short description on line:
       * bh_uptodate_or_lock: Test whether the buffer is uptodate
      Warning(mmotm-2008-0314-1449//fs/buffer.c:3240): missing initial short description on line:
       * bh_submit_read: Submit a locked buffer for reading
      Warning(mmotm-2008-0314-1449//fs/fs-writeback.c:30): missing initial short description on line:
       * writeback_acquire: attempt to get exclusive writeback access to a device
      Warning(mmotm-2008-0314-1449//fs/fs-writeback.c:47): missing initial short description on line:
       * writeback_in_progress: determine whether there is writeback in progress
      Warning(mmotm-2008-0314-1449//fs/fs-writeback.c:58): missing initial short description on line:
       * writeback_release: relinquish exclusive writeback access against a device.
      Warning(mmotm-2008-0314-1449//include/linux/jbd.h:351): contents before sections
      Warning(mmotm-2008-0314-1449//include/linux/jbd.h:561): contents before sections
      Warning(mmotm-2008-0314-1449//fs/jbd/transaction.c:1935): missing initial short description on line:
       * void journal_invalidatepage()
      Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      a6b91919
    • P
      rcu: fix misplaced mb() in rcu_enter/exit_nohz() · ae66be9b
      Paul E. McKenney 提交于
      In the process of writing up the mechanical proof of correctness for the
      dynticks/preemptable-RCU interface, I noticed misplaced memory barriers in
      rcu_enter_nohz() and rcu_exit_nohz().
      
      This patch puts them in the right place and adds a comment.  The key thing to
      keep in mind is that rcu_enter_nohz() is -exiting- the mode that can legally
      execute RCU read-side critical sections.
      
      The memory barrier must be between any potential RCU read-side critical
      sections and the increment of the per-CPU dynticks_progress_counter, and thus
      must come -before- this increment.  And vice versa for rcu_exit_nohz().
      
      The locking in the scheduler is probably saving us for the moment.
      
      Also, switch to smp_mb() - we don't need a barrier for uniprocessor kernels.
      Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
      Acked-by: NSteven Rostedt <srostedt@redhat.com>
      Cc: Nick Piggin <nickpiggin@yahoo.com.au>
      Cc: Oleg Nesterov <oleg@tv-sign.ru>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      ae66be9b
  6. 19 3月, 2008 2 次提交
    • I
      sched: tune multi-core idle balancing · 33b0c421
      Ingo Molnar 提交于
      WAKE_IDLE is too agressive on multi-core CPUs with the new
      wake-affine code, keep it on for SMT/HT balancing alone
      (where there's no cache affinity at all between logical CPUs).
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      33b0c421
    • I
      sched: improve affine wakeups · 4ae7d5ce
      Ingo Molnar 提交于
      improve affine wakeups. Maintain the 'overlap' metric based on CFS's
      sum_exec_runtime - which means the amount of time a task executes
      after it wakes up some other task.
      
      Use the 'overlap' for the wakeup decisions: if the 'overlap' is short,
      it means there's strong workload coupling between this task and the
      woken up task. If the 'overlap' is large then the workload is decoupled
      and the scheduler will move them to separate CPUs more easily.
      
      ( Also slightly move the preempt_check within try_to_wake_up() - this has
        no effect on functionality but allows 'early wakeups' (for still-on-rq
        tasks) to be correctly accounted as well.)
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      4ae7d5ce
  7. 18 3月, 2008 2 次提交
  8. 17 3月, 2008 3 次提交
    • T
      devres: implement pcim_iomap_regions_request_all() · 916fbfb7
      Tejun Heo 提交于
      Some drivers need to reserve all PCI BARs to prevent other drivers
      misusing unoccupied BARs.  pcim_iomap_regions_request_all() requests
      all BARs and iomap specified BARs.
      Signed-off-by: NTejun Heo <htejun@gmail.com>
      Cc: Greg Kroah-Hartman <gregkh@suse.de>
      Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
      Cc: Jeff Garzik <jeff@garzik.org>
      Signed-off-by: NJeff Garzik <jeff@garzik.org>
      916fbfb7
    • C
      virtio: fix race in enable_cb · 4265f161
      Christian Borntraeger 提交于
      There is a race in virtio_net, dealing with disabling/enabling the callback.
      I saw the following oops:
      
      kernel BUG at /space/kvm/drivers/virtio/virtio_ring.c:218!
      illegal operation: 0001 [#1] SMP
      Modules linked in: sunrpc dm_mod
      CPU: 2 Not tainted 2.6.25-rc1zlive-host-10623-gd358142-dirty #99
      Process swapper (pid: 0, task: 000000000f85a610, ksp: 000000000f873c60)
      Krnl PSW : 0404300180000000 00000000002b81a6 (vring_disable_cb+0x16/0x20)
                 R:0 T:1 IO:0 EX:0 Key:0 M:1 W:0 P:0 AS:0 CC:3 PM:0 EA:3
      Krnl GPRS: 0000000000000001 0000000000000001 0000000010005800 0000000000000001
                 000000000f3a0900 000000000f85a610 0000000000000000 0000000000000000
                 0000000000000000 000000000f870000 0000000000000000 0000000000001237
                 000000000f3a0920 000000000010ff74 00000000002846f6 000000000fa0bcd8
      Krnl Code: 00000000002b819a: a7110001           tmll    %r1,1
                 00000000002b819e: a7840004           brc     8,2b81a6
                 00000000002b81a2: a7f40001           brc     15,2b81a4
                >00000000002b81a6: a51b0001           oill    %r1,1
                 00000000002b81aa: 40102000           sth     %r1,0(%r2)
                 00000000002b81ae: 07fe               bcr     15,%r14
                 00000000002b81b0: eb7ff0380024       stmg    %r7,%r15,56(%r15)
                 00000000002b81b6: a7f13e00           tmll    %r15,15872
      Call Trace:
      ([<000000000fa0bcd0>] 0xfa0bcd0)
       [<00000000002b8350>] vring_interrupt+0x5c/0x6c
       [<000000000010ab08>] do_extint+0xb8/0xf0
       [<0000000000110716>] ext_no_vtime+0x16/0x1a
       [<0000000000107e72>] cpu_idle+0x1c2/0x1e0
      
      The problem can be triggered with a high amount of host->guest traffic.
      I think its the following race:
      
      poll says netif_rx_complete
      poll calls enable_cb
      enable_cb opens the interrupt mask
      a new packet comes, an interrupt is triggered----\
      enable_cb sees that there is more work           |
      enable_cb disables the interrupt                 |
             .                                         V
             .                            interrupt is delivered
             .                            skb_recv_done does atomic napi test, ok
       some waiting                       disable_cb is called->check fails->bang!
             .
      poll would do napi check
      poll would do disable_cb
      
      The fix is to let enable_cb not disable the interrupt again, but expect the
      caller to do the cleanup if it returns false. In that case, the interrupt is
      only disabled, if the napi test_set_bit was successful.
      Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>
      Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (cleaned up doco)
      4265f161
    • A
      The ps2esdi driver was marked as BROKEN more than two years ago due to being · 2af3e601
      Adrian Bunk 提交于
      no longer working for some time.
      
      A driver that had been marked as BROKEN for such a long time seems to be
      unlikely to be revived in the forseeable future.
      
      But if anyone wants to ever revive this driver, the code is still present in
      the older kernel releases.
      Signed-off-by: NAdrian Bunk <bunk@kernel.org>
      Acked-by: NAlan Cox <alan@redhat.com>
      Cc: Jens Axboe <jens.axboe@oracle.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NJens Axboe <jens.axboe@oracle.com>
      2af3e601
  9. 15 3月, 2008 1 次提交
  10. 14 3月, 2008 1 次提交
    • G
      PCI: fix issue with busses registering multiple times in sysfs · cc74d96f
      Greg Kroah-Hartman 提交于
      PCI busses can be registered multiple times, so we need to detect if we
      have registered our bus structure in sysfs already.  If so, don't do it
      again.
      
      Thanks to Guennadi Liakhovetski <g.liakhovetski@gmx.de> for reporting
      the problem, and to Linus for poking me to get me to believe that it was
      a real problem.
      
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>
      cc74d96f
  11. 13 3月, 2008 4 次提交
  12. 11 3月, 2008 10 次提交
  13. 09 3月, 2008 2 次提交
  14. 08 3月, 2008 3 次提交