Some of the fancier slab debugging options are disabled for caches whose objects are larger than PAGE_SIZE/8, for speed/fragmentation reasons. But this patch turns up bugs in the size-2048 slab, so it was a bad idea. Enable the debugging for slabs up to 4096 bytes. mm/slab.c | 2 +- 1 files changed, 1 insertion(+), 1 deletion(-) diff -puN mm/slab.c~SLAB_STORE_USER-larger-objects mm/slab.c --- 25/mm/slab.c~SLAB_STORE_USER-larger-objects 2003-05-12 21:22:40.000000000 -0700 +++ 25-akpm/mm/slab.c 2003-05-12 21:22:40.000000000 -0700 @@ -949,7 +949,7 @@ kmem_cache_create (const char *name, siz * with object sizes just above a power of two have a significant * amount of internal fragmentation */ - if ((size < (PAGE_SIZE>>3) || fls(size-1) == fls(size-1+3*BYTES_PER_WORD)) + if ((size < 4096 || fls(size-1) == fls(size-1+3*BYTES_PER_WORD)) && !(flags & SLAB_MUST_HWCACHE_ALIGN)) { flags |= SLAB_RED_ZONE|SLAB_STORE_USER; } _