----- Original Message ----- Yes, I remember seeing the LKML post changing the slab structure from this: struct slab { struct list_head list; unsigned long colouroff; void *s_mem; /* including colour offset */ unsigned int inuse; /* num of objs active in slab */ kmem_bufctl_t free; unsigned short nodeid; }; to this: struct slab { union { struct { struct list_head list; unsigned long colouroff; void *s_mem; /* including colour offset */ unsigned int inuse; /* num of objs active in slab */ kmem_bufctl_t free; unsigned short nodeid; }; struct slab_rcu __slab_cover_slab_rcu; }; }; I had hoped that since the pre-existing fields had been moved into an anonymous union that the member offsets would be returned by gdb the same way. Apparently not: (gdb) ptype struct slab type = struct slab { union { struct {...}; struct slab_rcu __slab_cover_slab_rcu; }; } (gdb) But the offsets can be determined in another manner. Thanks, Dave