The patch titled Subject: Revert "slab: remove BAD_ALIEN_MAGIC" has been added to the -mm tree. Its filename is revert-slab-remove-bad_alien_magic.patch This patch should soon appear at http://ozlabs.org/~akpm/mmots/broken-out/revert-slab-remove-bad_alien_magic.patch and later at http://ozlabs.org/~akpm/mmotm/broken-out/revert-slab-remove-bad_alien_magic.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/SubmitChecklist when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx> Subject: Revert "slab: remove BAD_ALIEN_MAGIC" This reverts commit a640616822b2 ("slab: remove BAD_ALIEN_MAGIC"). commit a640616822b2 ("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: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx> Reported-by: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx> Cc: Christoph Lameter <cl@xxxxxxxxx> Cc: Pekka Enberg <penberg@xxxxxxxxxx> Cc: David Rientjes <rientjes@xxxxxxxxxx> Cc: Vladimir Davydov <vdavydov@xxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/slab.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff -puN mm/slab.c~revert-slab-remove-bad_alien_magic mm/slab.c --- a/mm/slab.c~revert-slab-remove-bad_alien_magic +++ a/mm/slab.c @@ -470,6 +470,8 @@ static struct kmem_cache kmem_cache_boot .name = "kmem_cache", }; +#define BAD_ALIEN_MAGIC 0x01020304ul + static DEFINE_PER_CPU(struct delayed_work, slab_reap_work); static inline struct array_cache *cpu_cache_get(struct kmem_cache *cachep) @@ -836,7 +838,7 @@ static int transfer_objects(struct array static inline struct alien_cache **alloc_alien_cache(int node, int limit, gfp_t gfp) { - return NULL; + return (struct alien_cache **)BAD_ALIEN_MAGIC; } static inline void free_alien_cache(struct alien_cache **ac_ptr) _ Patches currently in -mm which might be from iamjoonsoo.kim@xxxxxxx are origin.patch revert-slab-remove-bad_alien_magic.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html