1. 14 Aug, 2008 2 commits
    • Peter Zijlstra's avatar
      sched: fix rt-bandwidth hotplug race · f1679d08
      Peter Zijlstra authored
      When we hot-unplug a cpu and rebuild the sched-domain, all cpus will be
      detatched. Alex observed the case where a runqueue was stealing bandwidth
      from an already disabled runqueue to satisfy its own needs.
      
      Stop this by skipping over already disabled runqueues.
      Reported-by: default avatarAlex Nixon <alex.nixon@citrix.com>
      Signed-off-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
      Tested-by: default avatarAlex Nixon <alex.nixon@citrix.com>
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      f1679d08
    • Zhang, Yanmin's avatar
      sched: fix the race between walk_tg_tree and sched_create_group · 09f2724a
      Zhang, Yanmin authored
      With 2.6.27-rc3, I hit a kernel panic when running volanoMark on my
      new x86_64 machine. I also hit it with other 2.6.27-rc kernels.
      See below log.
      
      Basically, function walk_tg_tree and sched_create_group have a race
      between accessing and initiating tg->children. Below patch fixes it
      by moving tg->children initiation to the front of linking tg->siblings
      to parent->children.
      
      {----------------panic log------------}
      
      BUG: unable to handle kernel NULL pointer dereference at 0000000000000000
      IP: [<ffffffff802292ab>] walk_tg_tree+0x45/0x7f
      PGD 1be1c4067 PUD 1bdd8d067 PMD 0
      Oops: 0000 [1] SMP
      CPU 11
      Modules linked in: igb
      Pid: 22979, comm: java Not tainted 2.6.27-rc3 #1
      RIP: 0010:[<ffffffff802292ab>]  [<ffffffff802292ab>] walk_tg_tree+0x45/0x7f
      RSP: 0018:ffff8801bfbbbd18  EFLAGS: 00010083
      RAX: 0000000000000000 RBX: ffff8800be0dce40 RCX: ffffffffffffffc0
      RDX: ffff880102c43740 RSI: 0000000000000000 RDI: ffff8800be0dce40
      RBP: ffff8801bfbbbd48 R08: ffff8800ba437bc8 R09: 0000000000001f40
      R10: ffff8801be812100 R11: ffffffff805fdf44 R12: ffff880102c43740
      R13: 0000000000000000 R14: ffffffff8022cf0f R15: ffffffff8022749f
      FS:  00000000568ac950(0063) GS:ffff8801bfa26d00(0000) knlGS:0000000000000000
      CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
      CR2: 0000000000000000 CR3: 00000001bd848000 CR4: 00000000000006e0
      DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
      DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
      Process java (pid: 22979, threadinfo ffff8801b145a000, task ffff8801bf18e450)
      Stack:  0000000000000001 ffff8800ba5c8d60 0000000000000001 0000000000000001
       ffff8800bad1ccb8 0000000000000000 ffff8801bfbbbd98 ffffffff8022ed37
       0000000000000001 0000000000000286 ffff8801bd5ee180 ffff8800ba437bc8
      Call Trace:
       <IRQ>  [<ffffffff8022ed37>] try_to_wake_up+0x71/0x24c
       [<ffffffff80247177>] autoremove_wake_function+0x9/0x2e
       [<ffffffff80228039>] ? __wake_up_common+0x46/0x76
       [<ffffffff802296d5>] __wake_up+0x38/0x4f
       [<ffffffff806169cc>] tcp_v4_rcv+0x380/0x62e
      Signed-off-by: default avatarZhang Yanmin <yanmin_zhang@linux.intel.com>
      Acked-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      09f2724a
  2. 13 Aug, 2008 1 commit
  3. 12 Aug, 2008 37 commits