1. 15 3月, 2008 5 次提交
    • P
      sched: min_vruntime fix · 3fe69747
      Peter Zijlstra 提交于
      Current min_vruntime tracking is incorrect and will cause serious
      problems when we don't run the leftmost task for some reason.
      
      min_vruntime does two things; 1) it's used to determine a forward
      direction when the u64 vruntime wraps, 2) it's used to track the
      leftmost vruntime to position newly enqueued tasks from.
      
      The current logic advances min_vruntime whenever the current task's
      vruntime advance. Because the current task may pass the leftmost task
      still waiting we're failing the second goal. This causes new tasks to be
      placed too far ahead and thus penalizes their runtime.
      
      Fix this by making min_vruntime the min_vruntime of the waiting tasks by
      tracking it in enqueue/dequeue, and compare against current's vruntime
      to obtain the absolute minimum when placing new tasks.
      Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      3fe69747
    • H
      sched: fix race in schedule() · 0e1f3483
      Hiroshi Shimamoto 提交于
      Fix a hard to trigger crash seen in the -rt kernel that also affects
      the vanilla scheduler.
      
      There is a race condition between schedule() and some dequeue/enqueue
      functions; rt_mutex_setprio(), __setscheduler() and sched_move_task().
      
      When scheduling to idle, idle_balance() is called to pull tasks from
      other busy processor. It might drop the rq lock. It means that those 3
      functions encounter on_rq=0 and running=1. The current task should be
      put when running.
      
      Here is a possible scenario:
      
         CPU0                               CPU1
          |                              schedule()
          |                              ->deactivate_task()
          |                              ->idle_balance()
          |                              -->load_balance_newidle()
      rt_mutex_setprio()                     |
          |                              --->double_lock_balance()
          *get lock                          *rel lock
          * on_rq=0, ruuning=1               |
          * sched_class is changed           |
          *rel lock                          *get lock
          :                                  |
                                             :
                                         ->put_prev_task_rt()
                                         ->pick_next_task_fair()
                                             => panic
      
      The current process of CPU1(P1) is scheduling. Deactivated P1, and the
      scheduler looks for another process on other CPU's runqueue because CPU1
      will be idle. idle_balance(), load_balance_newidle() and
      double_lock_balance() are called and double_lock_balance() could drop
      the rq lock. On the other hand, CPU0 is trying to boost the priority of
      P1. The result of boosting only P1's prio and sched_class are changed to
      RT. The sched entities of P1 and P1's group are never put. It makes
      cfs_rq invalid, because the cfs_rq has curr and no leaf, but
      pick_next_task_fair() is called, then the kernel panics.
      Signed-off-by: NHiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
      Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      0e1f3483
    • L
      Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394-2.6 · 4faa8496
      Linus Torvalds 提交于
      * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394-2.6:
        firewire: fw-ohci: shut up false compiler warning on PPC32
        firewire: fw-ohci: use dma_alloc_coherent for ar_buffer
        ieee1394: sbp2: fix for SYM13FW500 bridge (Datafab disk)
        firewire: fw-sbp2: fix for SYM13FW500 bridge (Datafab disk)
        firewire: update Kconfig help text
        firewire: warn on fatal condition in topology code
        firewire: fw-sbp2: set single-phase retry_limit
        firewire: fw-ohci: Apple UniNorth 1st generation support
        firewire: fw-ohci: PPC PMac platform code
        firewire: endianess annotations
        firewire: endianess fix
      4faa8496
    • J
      nfsd: fix oops on access from high-numbered ports · b663c6fd
      J. Bruce Fields 提交于
      This bug was always here, but before my commit 6fa02839
      ("recheck for secure ports in fh_verify"), it could only be triggered by
      failure of a kmalloc().  After that commit it could be triggered by a
      client making a request from a non-reserved port for access to an export
      marked "secure".  (Exports are "secure" by default.)
      
      The result is a struct svc_export with a reference count one too low,
      resulting in likely oopses next time the export is accessed.
      
      The reference counting here is not straightforward; a later patch will
      clean up fh_verify().
      
      Thanks to Lukas Hejtmanek for the bug report and followup.
      Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
      Cc: Lukas Hejtmanek <xhejtman@ics.muni.cz>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      b663c6fd
    • M
      struct export_operations: adjust comments to match current members · 9b89ca7a
      Marc Dionne 提交于
      The comments in the definition of struct export_operations don't match the
      current members.
      
      Add a comment for the 2 new functions and remove 2 comments for unused ones.
      Signed-off-by: NMarc Dionne <marc.c.dionne@gmail.com>
      Acked-by: NDavid Howells <dhowells@redhat.com>
      Acked-by: NChristoph Hellwig <hch@lst.de>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      9b89ca7a
  2. 14 3月, 2008 32 次提交
  3. 13 3月, 2008 3 次提交