• Joonsoo Kim's avatar
    Revert "slab: remove BAD_ALIEN_MAGIC" · edcad250
    Joonsoo Kim authored
    This reverts commit a6406168 ("slab: remove BAD_ALIEN_MAGIC").
    
    commit a6406168 ("slab: remove BAD_ALIEN_MAGIC") assumes that the
    system with !CONFIG_NUMA has only one memory node.  But, it turns out to
    be false by the report from Geert.  His system, m68k, has many memory
    nodes and is configured in !CONFIG_NUMA.  So it couldn't boot with above
    change.
    
    Here goes his failure report.
    
      With latest mainline, I'm getting a crash during bootup on m68k/ARAnyM:
    
      enable_cpucache failed for radix_tree_node, error 12.
      kernel BUG at /scratch/geert/linux/linux-m68k/mm/slab.c:1522!
      *** TRAP #7 ***   FORMAT=0
      Current process id is 0
      BAD KERNEL TRAP: 00000000
      Modules linked in:
      PC: [<0039c92c>] kmem_cache_init_late+0x70/0x8c
      SR: 2200  SP: 00345f90  a2: 0034c2e8
      d0: 0000003d    d1: 00000000    d2: 00000000    d3: 003ac942
      d4: 00000000    d5: 00000000    a0: 0034f686    a1: 0034f682
      Process swapper (pid: 0, task=0034c2e8)
      Frame format=0
      Stack from 00345fc4:
              002f69ef 002ff7e5 000005f2 000360fa 0017d806 003921d4 00000000
              00000000 00000000 00000000 00000000 00000000 003ac942 00000000
              003912d6
      Call Trace: [<000360fa>] parse_args+0x0/0x2ca
       [<0017d806>] strlen+0x0/0x1a
       [<003921d4>] start_kernel+0x23c/0x428
       [<003912d6>] _sinittext+0x2d6/0x95e
    
      Code: f7e5 4879 002f 69ef 61ff ffca 462a 4e47 <4879> 0035 4b1c 61ff
      fff0 0cc4 7005 23c0 0037 fd20 588f 265f 285f 4e75 48e7 301c
      Disabling lock debugging due to kernel taint
      Kernel panic - not syncing: Attempted to kill the idle task!
    
    Although there is a alternative way to fix this issue such as disabling
    use of alien cache on !CONFIG_NUMA, but, reverting issued commit is better
    to me in this time.
    Signed-off-by: default avatarJoonsoo Kim <iamjoonsoo.kim@lge.com>
    Reported-by: default avatarGeert Uytterhoeven <geert@linux-m68k.org>
    Cc: Christoph Lameter <cl@linux.com>
    Cc: Pekka Enberg <penberg@kernel.org>
    Cc: David Rientjes <rientjes@google.com>
    Cc: Vladimir Davydov <vdavydov@parallels.com>
    Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    edcad250
slab.c 109 KB