2014-08-07 20:52 GMT+09:00 Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>: > Hi Joonsoo, > > On Tue, Jul 1, 2014 at 10:27 AM, Joonsoo Kim <iamjoonsoo.kim@xxxxxxx> wrote: >> BAD_ALIEN_MAGIC value isn't used anymore. So remove it. >> >> Acked-by: Christoph Lameter <cl@xxxxxxxxx> >> Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx> >> --- >> mm/slab.c | 4 +--- >> 1 file changed, 1 insertion(+), 3 deletions(-) >> >> diff --git a/mm/slab.c b/mm/slab.c >> index 7820a45..60c9e11 100644 >> --- a/mm/slab.c >> +++ b/mm/slab.c >> @@ -470,8 +470,6 @@ 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) >> @@ -838,7 +836,7 @@ static int transfer_objects(struct array_cache *to, >> static inline struct alien_cache **alloc_alien_cache(int node, >> int limit, gfp_t gfp) >> { >> - return (struct alien_cache **)BAD_ALIEN_MAGIC; >> + return NULL; >> } > > 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! > ---[ end Kernel panic - not syncing: Attempted to kill the idle task! > > I bisected it to commit a640616822b2c3a8009b0600f20c4a76ea8a0025 > Author: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx> > Date: Wed Aug 6 16:04:38 2014 -0700 > > slab: remove BAD_ALIEN_MAGIC > > BAD_ALIEN_MAGIC value isn't used anymore. So remove it. > > Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx> > Acked-by: Christoph Lameter <cl@xxxxxxxxx> > Cc: Pekka Enberg <penberg@xxxxxxxxxx> > Cc: David Rientjes <rientjes@xxxxxxxxxx> > Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> > Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> > > Error 12 is ENOMEM, so I first thought it went out-of-memory, but just reverting > the above commit on mainline makes it work again. Hello, Thanks for reporting. This patch only works for !NUMA. And if num_possible_nodes() is 1, then it doesn't have any effect, because alloc_alien_cache() call is always skipped. Is it possible !NUMA and num_possible_nodes() != 1? Could you check your config for CONFIG_NUMA and CONFIG_NODES_SHIFT? And, could you check booting with boot param "noaliencache"? Thanks. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx"> email@xxxxxxxxx </a>